SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

airfoil-self-noise

claude-code claude-opus-4-8 ✗ failed GOOD_FAILURE ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_FAILUREHonest miss, the agent ran correctly but couldn't solve it. Expected for a hard task; the task is sound.
SubtypeComplexity Overwhelm
EvidenceAgent achieved rmse≈2.12 (✓ vs ≤2.25), mae≈1.55 (borderline vs ≤1.55), p95≈3.35 (✓ vs ≤4.75), max≈5.28 (✓ vs ≤5.60), but p90≈3.0 (✗ vs ≤2.35 target). Final reward=0.43, below pass threshold ≥0.50. Agent's own grouped-CV validation clearly showed 4/5 metrics passing with p90 as bottleneck. Test output: 'score: 0.43 < 0.5 => reward = 0.0 (FAIL)'.
Root causeThe agent faced a fundamental generalization ceiling: interpolation (random CV) achieves p90≈2.22, but extrapolating to completely unseen (angle, chord, velocity) conditions plateaus at p90≈3.0. Despite thorough feature engineering (Strouhal, Reynolds, physics-based features), ensemble methods (ExtraTrees, HistGBM, MLPs), and extensive validation, the agent could not bridge the ~0.65 unit gap between its best p90 and the target 2.35.
RecommendationN/A - task is fine. The instruction is clear, tests are reasonable, and required information is available. The agent executed a sophisticated, well-validated approach but hit a genuine problem difficulty ceiling. This is expected for hard benchmark tasks (20-40% pass rate).
Trajectory
Tool-by-tool agent trajectory
251 tool calls · 3 tool types · 251 steps
# Airfoil Self-Noise Surrogate Build a regression surrogate for airfoil self-noise using a calibrated benchmark derived from the public UCI Airfoil Self-Noise measurements. Your starting script is: - `/app/train_and_predict.py` The grader discards any pre-existing `/app/output/predictions.csv`, stages hidden feature-only rows at `/app/data/test_features.csv`, and re-runs `python3 /app/train_and_predict.py`. Put the complete training and prediction workflow in that script, or in helper files that the script imports. Your solution must train from the labeled public data and write predictions for the grader-staged evaluation features during that re-run. ## Data Candidate-visible data: - `/app/data/train.csv`: labeled training rows. - `/app/data/validation.csv`: labeled validation rows for local tuning. - `/app/data/test_features.csv`: feature-only evaluation rows. The repository copy is a small local placeholder; during scoring, the grader replaces it with hidden feature rows using the same schema. Each labeled row has: - `sample_id` - `frequency` - `attack_angle` - `chord_length` - `free_stream_velocity` - `suction_side_displacement_thickness` - `scaled_sound_pressure_level` The target is a calibrated `scaled_sound_pressure_level` in dB. The hidden labels are not in `/app` and are not available during prediction. Raw labels copied from external UCI files are not valid labels for this benchmark and may be rejected as source-label leakage. The split holds out complete aerodynamic condition groups, where a condition is the tuple `(attack_angle, chord_length, free_stream_velocity)`. This means the hidden set tests generalization to unseen physical regimes, not just interpolation across nearby rows. ## Required Output When `python3 /app/train_and_predict.py` is re-run by the grader, it must write: - `/app/output/predictions.csv` The CSV must have exactly these columns: ```text sample_id,predicted_scaled_sound_pressure_level ``` Rules: - Include exactly one row for every `sample_id` in `/app/data/test_features.csv`. - Predictions must be numeric and finite. - Do not modify the input CSV files. - Do not use external data or runtime internet access. - Do not read or tamper with `/tests`, `/grader`, `/mcp_server`, or verifier/log reward paths. ## Scoring The verifier recomputes metrics from your predictions and hidden labels: - `hidden_rmse` - `hidden_mae` - `hidden_p90_condition_rmse` - `hidden_p95_condition_rmse` - `hidden_max_condition_rmse` The primary objective is reliable generalization across held-out aerodynamic regimes. Optimize for low global error while avoiding large per-condition failures. The `hidden_p90_condition_rmse`, `hidden_p95_condition_rmse`, and `hidden_max_condition_rmse` metrics penalize models that perform well on average but fail on specific unseen physical settings. The solved boundary is bottlenecked by the required global and per-condition metrics, including the single worst held-out condition. Reward uses the ML4Eng Reward V3 convention: - `reward >= 0.50` means solved. - Reward is bottlenecked by the weakest required metric. - Missing, stale, malformed, constant, non-finite, misaligned, or implausibly exact outputs receive `0.0`. To pass the solved boundary, all required metrics must meet the hidden targets: - `hidden_rmse <= 2.25` - `hidden_mae <= 1.55` - `hidden_p90_condition_rmse <= 2.35` - `hidden_p95_condition_rmse <= 4.75` - `hidden_max_condition_rmse <= 5.60`
Let me start by exploring the environment to understand what we're working with.
I'll start by exploring the environment and understanding the data and starting script.
bash
cd /app && ls -la && echo "---DATA---" && ls -la data/ && echo "---SCRIPT---" && cat train_and_predict.py
output
total 20
drwxrws---  4 h2tagent h2tagent 4096 Jun 21 05:20 .
drwxr-xr-x 26 root     root     4096 Jun 21 05:25 ..
drwxrws---  2 h2tagent h2tagent 4096 Jun 21 05:20 data
drwxrws---  2 h2tagent h2tagent 4096 Jun 21 05:20 output
-rwxrwx---  1 h2tagent h2tagent 3211 Jun 21 05:18 train_and_predict.py
---DATA---
total 128
drwxrws--- 2 h2tagent h2tagent  4096 Jun 21 05:20 .
drwxrws--- 4 h2tagent h2tagent  4096 Jun 21 05:20 ..
-rw-rw---- 1 h2tagent h2tagent  3595 Jun 21 05:18 test_features.csv
-rw-rw---- 1 h2tagent h2tagent 97417 Jun 21 05:18 train.csv
-rw-rw---- 1 h2tagent h2tagent 20351 Jun 21 05:18 validation.csv
---SCRIPT---
#!/usr/bin/env python3
"""Starter baseline for the Airfoil Self-Noise surrogate task.

This deliberately modest Ridge model is useful as a working end-to-end
baseline, but it is not strong enough to clear the hidden grouped split.
"""

from pathlib import Path

import numpy as np
import pandas as pd
from sklearn.base import BaseEstimator, TransformerMixin
from sklearn.linear_model import Ridge
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler


DATA_DIR = Path("/app/data")
OUTPUT_DIR = Path("/app/output")
TARGET = "scaled_sound_pressure_level"
PREDICTION = "predicted_scaled_sound_pressure_level"
FEATURES = [
    "frequency",
    "attack_angle",
    "chord_length",
    "free_stream_velocity",
    "suction_side_displacement_thickness",
]


class AirfoilFeatures(BaseEstimator, TransformerMixin):
    def fit(self, X, y=None):
        return self

    def transform(self, X):
        frame = pd.DataFrame(X, columns=FEATURES if not isinstance(X, pd.DataFrame) else X.columns)
        frequency = frame["frequency"].astype(float)
        angle = frame["attack_angle"].astype(float)
        chord = frame["chord_length"].astype(float)
        velocity = frame["free_stream_velocity"].astype(float)
        thickness = frame["suction_side_displacement_thickness"].astype(float)

        log_frequency = np.log10(frequency)
        log_thickness = np.log10(thickness)
        out = pd.DataFrame(index=frame.index)
        out["frequency"] = frequency
        out["attack_angle"] = angle
        out["chord_length"] = chord
        out["free_stream_velocity"] = velocity
        out["suction_side_displacement_thickness"] = thickness
        out["log_frequency"] = log_frequency
        out["log_thickness"] = log_thickness
        out["freq_velocity"] = log_frequency * velocity
        out["freq_angle"] = log_frequency * angle
        out["angle_velocity"] = angle * velocity
        out["thickness_angle"] = log_thickness * angle
        out["chord_velocity"] = chord * velocity
        return out.to_numpy(dtype=float)


def load_labeled_data() -> pd.DataFrame:
    parts = [pd.read_csv(DATA_DIR / "train.csv")]
    validation_path = DATA_DIR / "validation.csv"
    if validation_path.exists():
        parts.append(pd.read_csv(validation_path))
    return pd.concat(parts, ignore_index=True)


def load_evaluation_features() -> pd.DataFrame:
    test_path = DATA_DIR / "test_features.csv"
    if test_path.exists():
        return pd.read_csv(test_path)
    validation = pd.read_csv(DATA_DIR / "validation.csv")
    return validation.drop(columns=[TARGET])


def main() -> None:
    labeled = load_labeled_data()
    evaluation = load_evaluation_features()

    model = make_pipeline(
        AirfoilFeatures(),
        StandardScaler(),
        Ridge(alpha=10.0),
    )
    model.fit(labeled[FEATURES], labeled[TARGET])
    predictions = model.predict(evaluation[FEATURES])

    OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
    pd.DataFrame(
        {
            "sample_id": evaluation["sample_id"].astype(str),
            PREDICTION: predictions,
        }
    ).to_csv(OUTPUT_DIR / "predictions.csv", index=False)


if __name__ == "__main__":
    main()
Let me explore the data files in detail.
Let me examine the data files in detail.
bash
cd /app && echo "=== TRAIN HEAD ===" && head -5 data/train.csv && echo "=== VALIDATION HEAD ===" && head -5 data/validation.csv && echo "=== TEST FEATURES ===" && cat data/test_features.csv && echo "=== COUNTS ===" && wc -l data/*.csv
output
=== TRAIN HEAD ===
sample_id,frequency,attack_angle,chord_length,free_stream_velocity,suction_side_displacement_thickness,scaled_sound_pressure_level
af_train_0000,5003.72368377,0.034997843085,0.101695197262,71.2730786718,0.00120791730525,131.375168508
af_train_0001,1997.22544774,15.6337827466,0.101571096822,71.3314610261,0.0436885053477,119.435701427
af_train_0002,1248.10938712,9.47742633424,0.0253695328899,31.6576914656,0.00461706652486,131.137445156
af_train_0003,200.228488983,15.5929878809,0.101720824729,39.5544682279,0.0527780201324,124.741187675
=== VALIDATION HEAD ===
sample_id,frequency,attack_angle,chord_length,free_stream_velocity,suction_side_displacement_thickness,scaled_sound_pressure_level
af_val_0000,1998.53240303,12.3252028109,0.101492415739,39.5853154533,0.040726689388,115.836432573
af_val_0001,629.718430551,0.0186262062548,0.152498614376,39.5692331074,0.00193529208188,124.213347611
af_val_0002,12482.9663422,0.0105284256024,0.0253720007765,71.3111171362,0.000400617998197,133.621156597
af_val_0003,1600.32755515,0.0338230474173,0.0253792825467,39.6448710656,0.000429527467403,123.534534482
=== TEST FEATURES ===
sample_id,frequency,attack_angle,chord_length,free_stream_velocity,suction_side_displacement_thickness
af_val_0000,1998.53240303,12.3252028109,0.101492415739,39.5853154533,0.040726689388
af_val_0001,629.718430551,0.0186262062548,0.152498614376,39.5692331074,0.00193529208188
af_val_0002,12482.9663422,0.0105284256024,0.0253720007765,71.3111171362,0.000400617998197
af_val_0003,1600.32755515,0.0338230474173,0.0253792825467,39.6448710656,0.000429527467403
af_val_0004,4991.52268156,4.79375092775,0.0254026486661,71.338126346,0.000846568200014
af_val_0005,2495.86144742,0.0184944330227,0.0253695232334,39.6589100769,0.000429048074288
af_val_0006,2498.46919499,-0.0221311526004,0.0507598806268,55.4715562727,0.00076139950933
af_val_0007,400.055023138,4.02558783258,0.22886423046,31.7065298471,0.00508038188852
af_val_0008,1252.05696213,-0.033956960167,0.0508312723036,55.4216023091,0.000760162781301
af_val_0009,3153.0620092,-0.0187379247997,0.304951229779,31.7266222719,0.0033172021384
af_val_0010,6291.52560924,4.80686739476,0.0253900657548,71.3076410261,0.000846622561216
af_val_0011,2499.48153179,-0.0283046278268,0.304802654945,31.714108322,0.00332017638188
af_val_0012,3993.42797965,0.00242905842755,0.050739046381,55.519571195,0.00076333790294
af_val_0013,801.236174603,4.8347627987,0.0253800677813,39.628200731,0.000906448464204
af_val_0014,2504.24785431,3.33499766708,0.101486169411,71.2230178916,0.00203328705957
af_val_0015,4005.91664864,8.43054742545,0.050781496492,55.5508996708,0.0054472470328
af_val_0016,5005.51202734,4.76602056341,0.0254146764802,39.5428889537,0.000909692343177
af_val_0017,3154.55089729,12.3017464063,0.101570667133,39.6195959364,0.0407647946879
af_val_0018,3149.80872579,4.77187008506,0.0254243421119,71.3870262412,0.000848159837222
af_val_0019,998.303428181,6.67736699996,0.101654592175,55.5085985719,0.00522649318285
af_val_0020,500.450561494,6.71452065018,0.101720542321,55.5692532656,0.00520929310826
af_val_0021,800.787357893,17.4061955392,0.025425336639,39.5642882537,0.017263191882
af_val_0022,2001.20577618,-0.0305587984668,0.0507820242688,55.4501707401,0.000760512564219
af_val_0023,1248.70725388,3.31526608552,0.101606401399,71.1937166404,0.0020275259469
af_val_0024,3155.2828154,9.87155886369,0.152415248344,31.7212258081,0.0253334961215
af_val_0025,314.994039148,12.2780378494,0.101717191597,39.5690644654,0.0408329489427
af_val_0026,798.931879537,6.68878460505,0.101694222023,55.5321482532,0.00522281130998
af_val_0027,998.333264845,12.334777031,0.101554460172,55.5374339048,0.0368430722189
af_val_0028,400.019432519,8.36524539981,0.0507588951123,55.4640708311,0.00543869067677
af_val_0029,3154.19523204,-0.0305966105622,0.152271629543,39.6592773927,0.00192823733416
af_val_0030,629.878625292,17.4184416215,0.0254162514745,39.5795196568,0.0172534371927
af_val_0031,3996.45293142,17.3779773937,0.0253787213084,39
…[truncated]
So we have: - 956 training rows - 201 validation rows - 40 test feature rows (placeholder - will be replaced by hidden data) The test_features.csv placeholder appears to be the same as the validation rows (af_val_0000 etc). Let me verify this. Let me look at the data more thoroughly. The target is "calibrated" scaled_sound_pressure_level. The original UCI Airfoil Self-Noise dataset has these exact features. But the task says raw labels from UCI are NOT valid (source-label leakage) , the labels here are "calibrated" so they differ from the raw UCI values. So we must train on the provided labels. Let me understand the structure better. The condition is the tuple (attack_angle, chord_length, free_stream_velocity). The split holds out complete aerodynamic condition groups. So in the hidden test set, there are conditions (combinations of attack_angle, chord_length, free_stream_velocity) not seen in training. Wait, but in the original UCI dataset, attack_angle, chord_length, free_stream_velocity take discrete values. Here the values look continuous/noisy (e.g., attack_angle 0.034997843085 instead of 0). So this is a "calibrated benchmark derived from" UCI with added noise to the features perhaps. Let me analyze the distributions. Let me check the unique values. Let me start doing data analysis.
The placeholder `test_features.csv` looks like the validation rows without labels. Let me analyze the data distributions and environment more deeply.
bash
cd /app && python3 -c "
import pandas as pd, numpy as np
tr = pd.read_csv('data/train.csv')
va = pd.read_csv('data/validation.csv')
print('train shape', tr.shape, 'val shape', va.shape)
print('--- TRAIN describe ---')
print(tr.describe().T)
print('--- target stats train ---')
print(tr['scaled_sound_pressure_level'].describe())
print('--- target stats val ---')
print(va['scaled_sound_pressure_level'].describe())
for c in ['attack_angle','chord_length','free_stream_velocity']:
    print(c, 'train unique approx:', tr[c].round(2).nunique(), 'val:', va[c].round(2).nunique())
"
output
train shape (956, 7) val shape (201, 7)
--- TRAIN describe ---
                                     count  ...           max
frequency                            956.0  ...  20025.582040
attack_angle                         956.0  ...     22.234770
chord_length                         956.0  ...      0.305164
free_stream_velocity                 956.0  ...     71.406950
suction_side_displacement_thickness  956.0  ...      0.058556
scaled_sound_pressure_level          956.0  ...    140.289040

[6 rows x 8 columns]
--- target stats train ---
count    956.000000
mean     125.402453
std        6.704146
min      104.935002
25%      121.083472
50%      126.104163
75%      130.491660
max      140.289040
Name: scaled_sound_pressure_level, dtype: float64
--- target stats val ---
count    201.000000
mean     126.483017
std        6.979769
min      109.788714
25%      122.161017
50%      127.178549
75%      131.746459
max      138.661407
Name: scaled_sound_pressure_level, dtype: float64
attack_angle train unique approx: 182 val: 56
chord_length train unique approx: 7 val: 7
free_stream_velocity train unique approx: 64 val: 52
The features appear to be continuous (noisy versions of discrete UCI values). Let me understand the "condition" grouping better. The condition is (attack_angle, chord_length, free_stream_velocity). Since these are noisy, each row might be its own condition unless they cluster. Actually wait. Let me look at the original UCI dataset structure. The original has: - Frequency (Hz): discrete values in 1/3 octave bands - Angle of attack (degrees): 0, 1.5, 3, ... discrete - Chord length (m): 0.0254, 0.0508, 0.1016, 0.1524, 0.2286, 0.3048 (6 values) - Free-stream velocity (m/s): 31.7, 39.6, 55.5, 71.3 (4 values) - Suction side displacement thickness (m) The target: Scaled sound pressure level (dB). In the original dataset, for a given (chord, velocity, angle) there's a sweep of frequencies, and the displacement thickness is determined by (angle, chord, velocity) , it's a derived quantity. So displacement thickness is a function of angle, chord, velocity (from boundary layer computations/XFOIL). Here the data is "calibrated" and noisy. The chord_length has ~6-7 unique values even when rounded to 2 decimals. Let me check the rounding. The condition tuple (attack_angle, chord_length, free_stream_velocity) , but these are noisy floats. So "complete aerodynamic condition groups" must be based on the underlying discrete values. Let me try to recover the discrete grid by rounding. Let me look at chord_length more carefully - it should be one of 6 discrete values.
bash
cd /app && python3 -c "
import pandas as pd, numpy as np
tr = pd.read_csv('data/train.csv')
va = pd.read_csv('data/validation.csv')
all_ = pd.concat([tr,va])
print('chord_length sorted unique rounded 3:')
print(np.sort(all_['chord_length'].round(3).unique()))
print('velocity rounded 0:')
print(np.sort(all_['free_stream_velocity'].round(0).unique()))
print('velocity rounded 1 nunique:', all_['free_stream_velocity'].round(1).nunique())
print('attack_angle rounded 0 unique:')
print(np.sort(all_['attack_angle'].round(0).unique()))
print('freq min max:', all_['frequency'].min(), all_['frequency'].max())
print('thickness min max:', all_['suction_side_displacement_thickness'].min(), all_['suction_side_displacement_thickness'].max())
"
output
chord_length sorted unique rounded 3:
[0.025 0.051 0.101 0.102 0.152 0.153 0.228 0.229 0.304 0.305]
velocity rounded 0:
[32. 40. 55. 56. 71.]
velocity rounded 1 nunique: 10
attack_angle rounded 0 unique:
[ 0.  1.  2.  3.  4.  5.  7.  8.  9. 10. 11. 12. 13. 15. 16. 17. 20. 22.]
freq min max: 199.660257517 20025.5820397
thickness min max: 0.000399693758684 0.0585560895273
The features are noisy versions of the discrete UCI grid. The chord lengths are clearly the 6 UCI values: 0.0254, 0.0508, 0.1016, 0.1524, 0.2286, 0.3048. Velocities: 31.7, 39.6, 55.5, 71.3. Attack angles: discrete set. So a "condition" = (attack_angle, chord_length, free_stream_velocity) on the underlying discrete grid. The noise added makes them slightly different per row. The key challenge: the hidden test set holds out complete conditions. So we need to generalize to unseen (angle, chord, velocity) combinations. The good news: the physics of airfoil self-noise is fairly smooth in these variables, and there's a well-known structure. The frequency dependence is the dominant one (a spectral shape peaking at some frequency), and the displacement thickness captures a lot. Let me think about the modeling. This is a classic dataset. A good model: gradient boosting (e.g., GradientBoostingRegressor, HistGradientBoostingRegressor) or a well-regularized model. But because we need to generalize to unseen condition groups, we should be careful about overfitting to specific conditions. Let me first check what's available: sklearn version, xgboost, lightgbm, etc. Let me also verify: the test_features.csv placeholder matches validation rows exactly (af_val IDs). So locally, I can use validation as a proxy for the hidden test. But the hidden test will hold out conditions not in train+validation? Actually the grader "stages hidden feature-only rows". The hidden set is a separate holdout. Let me re-read. "The split holds out complete aerodynamic condition groups" , so train, validation, and hidden test all have disjoint conditions. The validation set is given for local tuning. The hidden test is separate. So to estimate generalization, I should do group-based cross-validation on (train + validation) grouped by condition. Let me set that up. Let me check available libraries first.
The features are noisy versions of the canonical UCI discrete grid (chord ∈ {0.0254...0.3048}, velocity ∈ {31.7,39.6,55.5,71.3}, discrete angles). A "condition" is the underlying (angle, chord, velocity) tuple. Let me check available ML libraries.
bash
cd /app && python3 -c "
import sklearn; print('sklearn', sklearn.__version__)
import numpy, pandas, scipy; print('numpy', numpy.__version__, 'pandas', pandas.__version__, 'scipy', scipy.__version__)
for m in ['xgboost','lightgbm','catboost','torch','tensorflow']:
    try:
        mod=__import__(m); print(m, getattr(mod,'__version__','?'))
    except Exception as e:
        print(m, 'NOT available')
"
output
sklearn 1.4.2
numpy 1.26.4 pandas 2.2.2 scipy 1.17.1
xgboost NOT available
lightgbm NOT available
catboost NOT available
torch NOT available
tensorflow NOT available
Only sklearn is available (no xgboost/lightgbm). So I'll use sklearn's HistGradientBoostingRegressor, RandomForest, ExtraTrees, GradientBoosting, or combinations. Also linear/ridge with good features, GaussianProcess, KNN, SVR, MLP. Let me first confirm the test placeholder == validation features, and understand condition grouping by building a condition key from rounded values. Let me design a condition key. Since features are noisy, I need to snap to the nearest canonical grid value. Let me define canonical grids: - chord: [0.0254, 0.0508, 0.1016, 0.1524, 0.2286, 0.3048] - velocity: [31.7, 39.6, 55.5, 71.3] - angle: the UCI angles are 0, 1.5, 2.0?, ... Actually UCI angles: 0.0, 1.5, 3.0, 4.0, 5.3, 6.7, 7.3, 8.9, 9.9, 11.0, 12.3, 12.6, 15.4, 15.6, 17.4, 19.7, 22.2. Let me just snap angle to nearest 0.1 or cluster. Actually, for grouping by condition, I should cluster the rows. But for cross-validation to estimate hidden performance, I need to group by condition. Let me build groups by rounding: angle to nearest degree might merge distinct conditions (e.g., 15.4 and 15.6). Let me look at actual angle clusters. Actually, the purpose of grouping is for GroupKFold CV so that I hold out whole conditions. The noise means each physical condition has a cluster of angle values near the true value. Let me identify the canonical angles by clustering. Let me think differently. The original UCI dataset has 1503 rows. Here we have 956 + 201 = 1157 labeled + hidden. The hidden is maybe ~150-350 rows. Total might be ~1503 or a resampled calibrated version. For the condition grouping, let me snap each feature to canonical grid and form the key. Let me find canonical angle values by looking at a histogram.
Let me confirm the placeholder matches validation, and recover the canonical condition grid by snapping noisy features to nearest grid values.
bash
cd /app && python3 -c "
import pandas as pd, numpy as np
tr = pd.read_csv('data/train.csv'); va = pd.read_csv('data/validation.csv')
tf = pd.read_csv('data/test_features.csv')
# Is placeholder == validation features?
vm = va[tf.columns].reset_index(drop=True)
print('placeholder equals first 40 val rows:', np.allclose(vm.iloc[:40,1:].values, tf.iloc[:,1:].values))
print('ids match:', list(tf.sample_id[:3]), list(va.sample_id[:3]))
all_=pd.concat([tr,va])
ang=np.sort(all_['attack_angle'].values)
# cluster angles
clusters=[]; cur=[ang[0]]
for a in ang[1:]:
    if a-cur[-1]>0.5: clusters.append(cur); cur=[a]
    else: cur.append(a)
clusters.append(cur)
print('num angle clusters:', len(clusters))
print('angle cluster centers:', [round(np.mean(c),2) for c in clusters])
print('angle cluster spread(max-min):', [round(max(c)-min(c),3) for c in clusters][:20])
"
output
placeholder equals first 40 val rows: True
ids match: ['af_val_0000', 'af_val_0001', 'af_val_0002'] ['af_val_0000', 'af_val_0001', 'af_val_0002']
num angle clusters: 14
angle cluster centers: [-0.0, 1.82, 3.19, 4.04, 5.04, 7.1, 8.64, 9.72, 11.2, 12.48, 15.48, 17.4, 19.69, 22.2]
angle cluster spread(max-min): [0.07, 0.57, 0.37, 0.27, 0.67, 0.67, 0.57, 0.47, 0.07, 0.47, 0.27, 0.07, 0.063, 0.067]
The placeholder matches validation. Angle clusters are spread due to noise. Some clusters merge close UCI angles (e.g., 5.04 might be 5.3, and the cluster spread of 0.67 suggests multiple). Actually the noise spread makes clustering tricky. But for the purpose of grouping conditions for CV, I just need a reasonable grouping. Let me snap: - chord to nearest of [0.0254, 0.0508, 0.1016, 0.1524, 0.2286, 0.3048] - velocity to nearest of [31.7, 39.6, 55.5, 71.3] - angle to nearest canonical angle cluster center The noise on angle is up to ±0.35 degrees. Canonical UCI angles: 0, 1.5, 2.0?, 3.0, 4.0, 5.3, 6.7, 7.3, 8.9, 9.9, 11.0, 12.3, 12.6, 15.4, 15.6, 17.4, 19.7, 22.2. Some of these are <0.5 apart (12.3/12.6, 15.4/15.6) so they'd merge. That's fine for grouping , gives conservative (fewer, larger) groups. Actually for proper CV estimate that mirrors the grader's condition definition, I need to match how the grader defines conditions. The grader likely rounds or uses the exact tuple. But since features are noisy, the grader must snap them too. Hmm, actually maybe the grader defines conditions based on the TRUE underlying pre-noise values which we don't have. But regardless, for my CV, grouping by snapped condition is a good proxy. Let me build a robust snapping. Let me now focus on the key question: what model generalizes best to held-out conditions? Let me set up a GroupKFold CV harness grouped by condition, and evaluate candidate models with the same metrics the grader uses: - hidden_rmse (global RMSE) - hidden_mae - per-condition RMSE percentiles (p90, p95, max) Let me build the condition key, then the CV harness. Let me write a helper to snap features and form condition groups. Actually, let me reconsider. The displacement thickness is a derived quantity from (angle, chord, velocity) in the original dataset. Let me verify: is thickness essentially a deterministic function of (angle, chord, velocity)? If so, it won't add much beyond those. But it's a strong physical predictor. Let me check correlation. Let me now build the CV harness and test several models. I'll aim for robust generalization. Let me think about the feature engineering: - log10(frequency) is important (spectral shape) - log10(thickness) - Reynolds number ~ chord * velocity / nu - Strouhal number ~ frequency * thickness / velocity The classic approach (Brooks, Pope, Marcolini - BPM model) uses Strouhal number St = f * delta* / U. The scaled sound pressure level is often modeled as a function of Strouhal number. Let me engineer these physically meaningful features. Let me create a log10(frequency), log10(thickness), log10(strouhal = freq*thickness/velocity), etc. Let me build the harness.
Placeholder equals validation. Now let me build a GroupKFold CV harness (grouped by snapped condition) that mirrors the grader's metrics, so I can evaluate models' generalization to unseen conditions.
bash
cd /app && cat > /tmp/cv_harness.py << 'EOF'
import pandas as pd, numpy as np
from sklearn.model_selection import GroupKFold

CHORDS=np.array([0.0254,0.0508,0.1016,0.1524,0.2286,0.3048])
VELS=np.array([31.7,39.6,55.5,71.3])
ANGLES=np.array([0.0,1.5,3.0,4.0,5.3,6.7,7.3,8.9,9.9,11.0,12.3,12.6,15.4,15.6,17.4,19.7,22.2])

def snap(v, grid):
    return grid[np.argmin(np.abs(grid[None,:]-np.asarray(v)[:,None]),axis=1)]

def condition_key(df):
    c=snap(df['chord_length'].values,CHORDS)
    u=snap(df['free_stream_velocity'].values,VELS)
    a=snap(df['attack_angle'].values,ANGLES)
    return pd.Series([f"{ai:.1f}_{ci:.4f}_{ui:.1f}" for ai,ci,ui in zip(a,c,u)],index=df.index)

def metrics(y_true, y_pred, cond):
    y_true=np.asarray(y_true); y_pred=np.asarray(y_pred)
    err=y_pred-y_true
    rmse=np.sqrt(np.mean(err**2)); mae=np.mean(np.abs(err))
    dfm=pd.DataFrame({'c':np.asarray(cond),'e':err})
    cr=dfm.groupby('c')['e'].apply(lambda e: np.sqrt(np.mean(e**2)))
    return dict(rmse=rmse,mae=mae,p90=np.percentile(cr,90),p95=np.percentile(cr,95),maxc=cr.max(),ncond=len(cr))

def group_cv(make_model, X, y, groups, cond, n_splits=5, seed=0):
    gkf=GroupKFold(n_splits=n_splits)
    oof=np.zeros(len(y))
    for tri,tei in gkf.split(X,y,groups):
        m=make_model()
        m.fit(X.iloc[tri],y.iloc[tri])
        oof[tei]=m.predict(X.iloc[tei])
    return metrics(y,oof,cond), oof
EOF
echo "harness written"
output
harness written
Now let me verify my condition grouping is reasonable , count conditions and rows per condition, and check that snapping is clean (no ambiguous points far from grid).
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *
import pandas as pd, numpy as np
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
all_=pd.concat([tr,va],ignore_index=True)
# check snapping residuals
c=snap(all_['chord_length'].values,CHORDS); u=snap(all_['free_stream_velocity'].values,VELS); a=snap(all_['attack_angle'].values,ANGLES)
print('max chord snap resid %:', np.max(np.abs(c-all_.chord_length)/c)*100)
print('max vel snap resid %:', np.max(np.abs(u-all_.free_stream_velocity)/u)*100)
print('max angle snap resid (deg):', np.max(np.abs(a-all_.attack_angle)))
key=condition_key(all_)
print('num conditions total:', key.nunique(), 'rows:', len(all_))
print('rows per cond: min/median/max', key.value_counts().min(), key.value_counts().median(), key.value_counts().max())
# overlap train/val conditions
ktr=condition_key(tr); kva=condition_key(va)
print('train conds:', ktr.nunique(), 'val conds:', kva.nunique(), 'overlap:', len(set(ktr)&set(kva)))
"
output
max chord snap resid %: 0.11999999980314066
max vel snap resid %: 0.149999966919185
max angle snap resid (deg): 0.5349999137200001
num conditions total: 82 rows: 1157
rows per cond: min/median/max 8 14.0 18
train conds: 67 val conds: 15 overlap: 0
The condition grouping works well: - chord snaps within 0.12%, velocity within 0.15%, angle within 0.535 degrees (a bit high, max angle noise ~0.35 but 0.535 suggests some merge, e.g., angle near 12.45 is between 12.3 and 12.6 , snapping to nearest gives residual up to 0.15+noise). Actually 0.535 is larger than expected. But it's fine. - 82 conditions total, each with 8-18 rows (frequency sweeps). - train: 67 conditions, val: 15 conditions, ZERO overlap. This confirms the grouped split structure. The validation set has 15 held-out conditions , a good local proxy for the hidden test. Importantly, my angle snap residual of 0.535 suggests maybe angle 12.3/12.6 and 15.4/15.6 merging or an angle not in my list. Let me not worry, grouping is conservative. Now, key insight: the noise means a single physical condition might be slightly split. But 82 conditions with median 14 rows each (frequency sweeps) looks right. Original UCI: for each (chord, velocity, angle) there's a frequency sweep. Now, let me establish: 1. The validation set (15 conditions) as a held-out proxy. I can train on train.csv (67 conditions) and evaluate on validation.csv (15 conditions) , this directly mirrors the hidden test scenario (unseen conditions). 2. Also do GroupKFold on the combined data for a more robust estimate. Let me first get a baseline: the starter Ridge model. Then try better models. My evaluation protocol: - Protocol A: train on train.csv, predict validation.csv, compute metrics. (mirrors hidden) - Protocol B: GroupKFold CV over all 82 conditions. Let me check the targets I need to beat: - hidden_rmse <= 2.25 - hidden_mae <= 1.55 - hidden_p90_condition_rmse <= 2.35 - hidden_p95_condition_rmse <= 4.75 - hidden_max_condition_rmse <= 5.60 With only 15 val conditions, p90/p95/max are sensitive. p95 of 15 values ≈ the ~14th value (2nd largest). max is the worst condition. So I need the worst-condition RMSE <= 5.60 and 2nd worst <= 4.75 (roughly). These are the hardest. Let me build feature engineering with physics, then evaluate multiple models. Let me start.
Condition grouping is clean: 82 conditions, train/val have zero condition overlap (15 held-out val conditions). This mirrors the hidden split well. Let me engineer physics-informed features and benchmark models using two protocols: (A) train→validation, and (B) GroupKFold CV.
bash
cd /app && cat > /tmp/features.py << 'EOF'
import numpy as np, pandas as pd
RAW=["frequency","attack_angle","chord_length","free_stream_velocity","suction_side_displacement_thickness"]

def make_features(df):
    f=df['frequency'].astype(float); a=df['attack_angle'].astype(float)
    c=df['chord_length'].astype(float); u=df['free_stream_velocity'].astype(float)
    d=df['suction_side_displacement_thickness'].astype(float)
    o=pd.DataFrame(index=df.index)
    lf=np.log10(f); ld=np.log10(d); lc=np.log10(c); lu=np.log10(u)
    o['log_freq']=lf; o['attack_angle']=a; o['log_chord']=lc; o['log_vel']=lu; o['log_thick']=ld
    # physics: Strouhal number St = f*delta/U ; Reynolds ~ c*U
    o['log_strouhal']=np.log10(f*d/u)
    o['log_reynolds']=np.log10(c*u)
    o['log_reynolds_d']=np.log10(d*u)
    # interactions
    o['lf_angle']=lf*a
    o['lf_logthick']=lf*ld
    o['lf_logchord']=lf*lc
    o['lf_logvel']=lf*lu
    o['angle_logthick']=a*ld
    o['angle_logchord']=a*lc
    o['lf2']=lf*lf
    o['angle2']=a*a
    o['raw_freq']=f
    return o

def Xy(df):
    return make_features(df), df['scaled_sound_pressure_level']
EOF
python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *; from features import *
import pandas as pd, numpy as np
from sklearn.linear_model import Ridge
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
Xtr,ytr=Xy(tr); Xva,yva=Xy(va); condva=condition_key(va)
m=make_pipeline(StandardScaler(),Ridge(alpha=10.0)).fit(Xtr,ytr)
print('Ridge(phys feats) val:',{k:round(v,3) for k,v in metrics(yva,m.predict(Xva),condva).items()})
"
output
Ridge(phys feats) val: {'rmse': 4.727, 'mae': 3.56, 'p90': 6.702, 'p95': 7.609, 'maxc': 8.486, 'ncond': 15}
Ridge with physics features gets rmse 4.7 on validation , far from target 2.25. Linear is too weak. Let me try tree-based models (HistGradientBoosting, RandomForest, ExtraTrees) and also a tuned approach. Let me write a comprehensive model comparison script. I'll evaluate on both protocols. Let me evaluate several models on the train→val protocol first.
Linear is far too weak. Let me benchmark tree-based and other nonlinear models on both protocols.
bash
cd /app && cat > /tmp/bench.py << 'EOF'
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *; from features import *
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, RandomForestRegressor, ExtraTreesRegressor, GradientBoostingRegressor
from sklearn.neighbors import KNeighborsRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler

tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
Xtr,ytr=Xy(tr); Xva,yva=Xy(va); condva=condition_key(va)
alld=pd.concat([tr,va],ignore_index=True)
Xall,yall=Xy(alld); condall=condition_key(alld); groups=condall.values

def ev(name, make):
    m=make(); m.fit(Xtr,ytr)
    mv=metrics(yva,m.predict(Xva),condva)
    cvm,_=group_cv(make,Xall,yall,groups,condall,n_splits=5)
    print(f"{name:28s} VAL rmse={mv['rmse']:.3f} mae={mv['mae']:.3f} p90={mv['p90']:.2f} p95={mv['p95']:.2f} max={mv['maxc']:.2f} | CV rmse={cvm['rmse']:.3f} mae={cvm['mae']:.3f} p90={cvm['p90']:.2f} p95={cvm['p95']:.2f} max={cvm['maxc']:.2f}")

ev('HGB default', lambda: HistGradientBoostingRegressor(random_state=0))
ev('HGB l2=1,lr.05,leaf31', lambda: HistGradientBoostingRegressor(max_iter=600,learning_rate=0.05,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=20,random_state=0))
ev('RF 500', lambda: RandomForestRegressor(n_estimators=500,n_jobs=-1,random_state=0))
ev('ExtraTrees 500', lambda: ExtraTreesRegressor(n_estimators=500,n_jobs=-1,random_state=0))
ev('KNN10', lambda: make_pipeline(StandardScaler(),KNeighborsRegressor(n_neighbors=10,weights='distance')))
ev('SVR rbf', lambda: make_pipeline(StandardScaler(),SVR(C=20,gamma='scale',epsilon=0.1)))
ev('MLP', lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=2000,alpha=1e-3,random_state=0)))
EOF
python3 /tmp/bench.py
output
HGB default                  VAL rmse=2.603 mae=2.052 p90=3.39 p95=3.82 max=4.53 | CV rmse=2.665 mae=1.964 p90=4.01 p95=4.74 max=6.50
HGB l2=1,lr.05,leaf31        VAL rmse=2.552 mae=1.991 p90=3.48 p95=3.83 max=4.39 | CV rmse=2.572 mae=1.879 p90=3.85 p95=4.42 max=5.77
RF 500                       VAL rmse=2.795 mae=2.219 p90=3.80 p95=3.93 max=4.00 | CV rmse=2.668 mae=2.009 p90=3.92 p95=4.32 max=5.29
ExtraTrees 500               VAL rmse=2.282 mae=1.802 p90=3.08 p95=3.33 max=3.64 | CV rmse=2.395 mae=1.783 p90=3.53 p95=3.93 max=5.71
KNN10                        VAL rmse=3.187 mae=2.436 p90=4.29 p95=4.84 max=5.62 | CV rmse=3.239 mae=2.455 p90=4.92 p95=5.54 max=6.88
SVR rbf                      VAL rmse=2.619 mae=1.892 p90=3.92 p95=4.16 max=4.32 | CV rmse=2.694 mae=1.902 p90=3.79 p95=4.57 max=8.63
MLP                          VAL rmse=2.717 mae=2.167 p90=3.91 p95=4.03 max=4.18 | CV rmse=2.868 mae=2.186 p90=4.10 p95=4.77 max=6.50
Good progress. ExtraTrees is the best so far with VAL rmse=2.282, mae=1.802, and CV rmse=2.395. But we need rmse<=2.25 and mae<=1.55 and p90<=2.35. All models are failing p90 (need <=2.35 but getting 3.0-4.0). The p90 target is very tight , need per-condition RMSE 90th percentile <= 2.35. Wait, the p90 target of 2.35 is close to the global rmse target of 2.25. That means MOST conditions need RMSE around 2 or less. This requires a genuinely accurate model. The mae target of 1.55 is also tight. ExtraTrees gets 1.8 mae. Let me reconsider. The features are noisy. The label is "calibrated". How much noise is in the labels? If labels have inherent noise of ~1-2 dB, then rmse ~2 might be near the floor. But the targets suggest rmse ~2 is achievable. Let me think about what's limiting. The big issue is generalizing to unseen conditions. Let me consider: 1. Better feature engineering , the physics (BPM model) strongly suggests the sound pressure level collapses onto functions of Strouhal number. Let me verify the relationships more carefully. 2. The displacement thickness delta* is key. In BPM, SPL = 10log(delta* * M^5 * L * Dh / r^2) + A(St/St_peak) + ... where M is Mach, St = f*delta*/U. So SPL depends on log(delta*), log(U) (through M^5), and a spectral shape function of St. Let me reconsider the feature set. Maybe I should combine features better. Let me check whether ExtraTrees on raw features vs engineered is better, and tune. Actually, let me reconsider the whole approach. Tree models don't extrapolate well to unseen conditions. Since the test holds out whole conditions (angle, chord, velocity combos), and trees partition on thresholds, they might do okay if the held-out condition is "interpolated" among training conditions in feature space. But angle/chord/velocity extremes would be extrapolation. Given physics structure, maybe a well-designed model combining: - A smooth physical model (GAM-like or polynomial in log features) for extrapolation - Plus tree/local corrections Let me try gradient boosting with more careful tuning and the physics features. Let me also try combining raw + engineered features for trees. Actually, let me step back and think about the target being "calibrated". The phrase "calibrated benchmark derived from the public UCI measurements" and "Raw labels copied from external UCI files are not valid labels... source-label leakage" strongly implies: they took the UCI data, and recalibrated the labels via some transformation (maybe a smooth function + noise), so that the mapping from features to label is a specific function we must learn. The features also got noise added. So essentially we must learn f(features) -> calibrated SPL. There is some irreducible noise. Let me estimate the noise floor: for conditions present in both... but train/val don't overlap in conditions. Let me estimate noise via: within a single condition (frequency sweep), the SPL varies smoothly with frequency. Fit a smooth curve per condition and look at residuals. That gives label noise estimate. Let me do that.
ExtraTrees is strongest so far (VAL rmse 2.28) but p90/mae targets remain tight. Let me estimate the label noise floor by fitting smooth curves within each condition's frequency sweep.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *
import pandas as pd, numpy as np
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
key=condition_key(alld)
alld['k']=key; alld['lf']=np.log10(alld.frequency)
res=[]
for k,g in alld.groupby('k'):
    if len(g)<6: continue
    x=g['lf'].values; y=g['scaled_sound_pressure_level'].values
    # fit cubic poly in log-frequency
    deg=min(4,len(g)-2)
    co=np.polyfit(x,y,deg); yp=np.polyval(co,x)
    res.append(y-yp)
res=np.concatenate(res)
print('within-condition residual std (deg<=4 fit): %.3f'%res.std())
print('within-condition residual RMSE: %.3f'%np.sqrt(np.mean(res**2)))
print('mean abs: %.3f'%np.mean(np.abs(res)))
"
output
within-condition residual std (deg<=4 fit): 1.014
within-condition residual RMSE: 1.014
mean abs: 0.672
The within-condition residual (after fitting a smooth curve in log-frequency for each condition) has RMSE ~1.0 dB. This is the approximate irreducible noise floor (label noise + feature noise + smoothness assumption). So an ideal model could get ~1.0 RMSE within known conditions. But for unseen conditions, we also have the error in predicting the curve itself. So the target rmse<=2.25 is achievable if we model the condition-level spectral shape well and the between-condition variation reasonably. This suggests a structured approach: model SPL as a smooth function of (log_freq and a peak frequency that depends on the condition) plus condition-level offsets. But for unseen conditions we must predict everything from features. The noise floor of 1.0 means mae floor ~0.67 within conditions. The target mae 1.55 is feasible. Let me focus on improving the model. The key metric bottlenecks are p90 (2.35) and mae (1.55) and rmse (2.25). ExtraTrees gives mae 1.78-1.80. I need to push down. Ideas: 1. Ensemble of diverse models (ExtraTrees + HGB + SVR + MLP) , averaging reduces variance and improves generalization. 2. Better features. 3. Target transformation. Let me think about the physics more. In the BPM model, the dominant scaling is: SPL ~ 10*log10(delta* * M^5 * L / r^2) + spectral_shape(St) where M = U/c_sound, L = span (= chord? no, L is span, constant here), delta* is displacement thickness. So SPL increases with log(delta*) and with 5*log(U) (M^5), and has a spectral shape that's a function of Strouhal number St = f*delta*/U, peaking at some St_peak. Key engineered features: - log_thick (log delta*) - log_vel (5*log U scaling) - log_strouhal = log(f*delta*/U) The spectral shape A(St) is a smooth function that rises then falls. Let me check: is there a strong collapse of (SPL - base) vs log_strouhal? Let me try a model that uses log_strouhal heavily. Actually, rather than over-engineering, let me try: 1. Ensemble averaging of the good models. 2. Also try adding polynomial/spline features for a ridge model that might generalize better (smooth). Let me build an ensemble and test. But first, let me tune ExtraTrees and HGB a bit more, and see if combining raw+engineered features helps trees. For trees, engineered log features can help splits. Let me test ExtraTrees with different feature sets. Let me also consider: since each condition is a frequency sweep, and frequency is the within-condition variable, the model needs to capture the spectral shape accurately. Trees can do this. Let me try an ensemble approach and also a GAM-like spline ridge. Let me set up a more systematic benchmark including ensembles.
The noise floor is ~1.0 dB RMSE, so targets are achievable with a strong model. The BPM physics suggests SPL collapses on Strouhal number with `log(δ*)` and velocity scalings. Let me test ensembles and richer feature sets, including spline features for smoothness.
bash
cd /app && cat > /tmp/bench2.py << 'EOF'
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *; from features import *
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, ExtraTreesRegressor, RandomForestRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler, SplineTransformer
from sklearn.linear_model import Ridge
from sklearn.base import BaseEstimator, RegressorMixin, clone

tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
Xtr,ytr=Xy(tr); Xva,yva=Xy(va); condva=condition_key(va)
alld=pd.concat([tr,va],ignore_index=True)
Xall,yall=Xy(alld); condall=condition_key(alld); groups=condall.values

class Avg(BaseEstimator,RegressorMixin):
    def __init__(self, models, weights=None):
        self.models=models; self.weights=weights
    def fit(self,X,y):
        self.fitted_=[clone(m).fit(X,y) for m in self.models]; return self
    def predict(self,X):
        P=np.column_stack([m.predict(X) for m in self.fitted_])
        w=np.ones(P.shape[1]) if self.weights is None else np.array(self.weights)
        return P@w/w.sum()

def ev(name, make):
    m=make(); m.fit(Xtr,ytr)
    mv=metrics(yva,m.predict(Xva),condva)
    cvm,_=group_cv(make,Xall,yall,groups,condall,n_splits=5)
    print(f"{name:26s} VAL rmse={mv['rmse']:.3f} mae={mv['mae']:.3f} p90={mv['p90']:.2f} p95={mv['p95']:.2f} max={mv['maxc']:.2f} | CV rmse={cvm['rmse']:.3f} mae={cvm['mae']:.3f} p90={cvm['p90']:.2f} p95={cvm['p95']:.2f} max={cvm['maxc']:.2f}")

et=lambda: ExtraTreesRegressor(n_estimators=800,min_samples_leaf=1,max_features=0.6,n_jobs=-1,random_state=0)
hgb=lambda: HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0)
svr=lambda: make_pipeline(StandardScaler(),SVR(C=30,gamma='scale',epsilon=0.05))
mlp=lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=3000,alpha=1e-3,random_state=0))
spl=lambda: make_pipeline(StandardScaler(),SplineTransformer(n_knots=5,degree=3),Ridge(alpha=1.0))

ev('ET tuned', et)
ev('HGB tuned', hgb)
ev('SVR tuned', svr)
ev('Spline-Ridge', spl)
ev('ENS ET+HGB', lambda: Avg([et(),hgb()]))
ev('ENS ET+HGB+SVR', lambda: Avg([et(),hgb(),svr()]))
ev('ENS ET+HGB+SVR+MLP', lambda: Avg([et(),hgb(),svr(),mlp()]))
ev('ENS ET2+HGB+SVR', lambda: Avg([et(),hgb(),svr()],weights=[2,1,1]))
EOF
python3 /tmp/bench2.py
output
ET tuned                   VAL rmse=2.312 mae=1.811 p90=2.97 p95=3.21 max=3.71 | CV rmse=2.458 mae=1.830 p90=3.45 p95=4.08 max=5.92
HGB tuned                  VAL rmse=2.664 mae=2.063 p90=3.39 p95=3.88 max=4.91 | CV rmse=2.586 mae=1.900 p90=3.83 p95=4.37 max=6.43
SVR tuned                  VAL rmse=2.650 mae=1.902 p90=4.09 p95=4.31 max=4.34 | CV rmse=2.721 mae=1.911 p90=3.77 p95=4.50 max=8.36
Spline-Ridge               VAL rmse=3.035 mae=2.360 p90=4.17 p95=4.52 max=5.09 | CV rmse=3.104 mae=2.328 p90=4.42 p95=5.07 max=6.50
ENS ET+HGB                 VAL rmse=2.356 mae=1.879 p90=3.25 p95=3.48 max=3.56 | CV rmse=2.409 mae=1.772 p90=3.49 p95=3.86 max=5.56
ENS ET+HGB+SVR             VAL rmse=2.312 mae=1.808 p90=3.31 p95=3.50 max=3.68 | CV rmse=2.272 mae=1.644 p90=3.32 p95=3.87 max=5.90
ENS ET+HGB+SVR+MLP         VAL rmse=2.284 mae=1.811 p90=3.25 p95=3.45 max=3.54 | CV rmse=2.209 mae=1.620 p90=3.25 p95=3.79 max=5.04
ENS ET2+HGB+SVR            VAL rmse=2.279 mae=1.789 p90=3.29 p95=3.45 max=3.48 | CV rmse=2.274 mae=1.660 p90=3.27 p95=3.84 max=5.43
The ensemble helps with rmse and mae (CV rmse down to ~2.2, mae down to ~1.62), but p90 is still ~3.2-3.5, far from target 2.35. The max condition is ~5.0-5.9, close to or over 5.60 target. The p90 target of 2.35 is the real bottleneck. That means 90% of conditions need RMSE <= 2.35. Currently only ~50-60% do. I need a fundamentally better model, not just ensembling. Let me reconsider. The within-condition noise floor is ~1.0. So per-condition RMSE has two parts: (1) the noise floor ~1.0, and (2) systematic bias in predicting that condition's curve. For p90 <= 2.35, most conditions need systematic error small enough that total RMSE <= 2.35, i.e., bias component <= sqrt(2.35^2 - 1.0^2) ≈ 2.13. So the model is making large systematic errors on many conditions. Why? Because trees don't extrapolate and the conditions are held out. Let me think about the physics-based structure more. The BPM model is quite accurate. Let me test whether the data follows a collapsible structure. If I can get SPL as a smooth function with the right physical variables, I can generalize to unseen conditions much better. Let me explore the relationship between SPL and log_strouhal, grouped. Let me look at how SPL depends on features. Actually, let me reconsider. The key issue is held-out conditions. Let me examine which validation conditions have the worst errors and see if they're extrapolation (e.g., extreme angle) cases. Let me look at per-condition errors for the ET model on validation.
Ensembling improves global RMSE/MAE but **p90 per-condition RMSE (~3.3) is far from the 2.35 target** , that's the true bottleneck. Trees extrapolate poorly to held-out conditions. Let me diagnose which validation conditions fail and whether the data follows a collapsible physical structure.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *; from features import *
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
Xtr,ytr=Xy(tr); Xva,yva=Xy(va); condva=condition_key(va)
m=ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=0).fit(Xtr,ytr)
pred=m.predict(Xva)
va['err']=pred-yva; va['k']=condva.values
cr=va.groupby('k').apply(lambda g: pd.Series({'rmse':np.sqrt(np.mean(g.err**2)),'bias':g.err.mean(),'n':len(g),
   'angle':g.attack_angle.mean(),'chord':g.chord_length.mean(),'vel':g.free_stream_velocity.mean()}))
print(cr.sort_values('rmse',ascending=False).round(2).to_string())
"
output
rmse  bias     n  angle  chord    vel
k                                                      
17.4_0.0254_39.6  3.71  0.04  15.0  17.40   0.03  39.58
0.0_0.0254_71.3   3.00 -0.18  10.0   0.02   0.03  71.35
12.3_0.1016_55.5  2.93 -1.90  16.0  12.30   0.10  55.51
12.3_0.1016_39.6  2.75 -2.50  16.0  12.30   0.10  39.58
6.7_0.1016_55.5   2.70 -1.53   8.0   6.68   0.10  55.50
0.0_0.3048_31.7   2.48  1.96  18.0   0.00   0.30  31.70
8.9_0.0508_55.5   2.47 -0.08  12.0   8.40   0.05  55.54
5.3_0.0254_39.6   2.32  0.98  14.0   4.80   0.03  39.58
4.0_0.2286_31.7   1.83 -0.93  15.0   4.00   0.23  31.68
0.0_0.0508_55.5   1.71 -0.20  13.0  -0.00   0.05  55.50
5.3_0.0254_71.3   1.69 -0.87  11.0   4.80   0.03  71.30
0.0_0.0254_39.6   1.59  0.13  11.0  -0.01   0.03  39.63
0.0_0.1524_39.6   1.22  0.26  14.0  -0.01   0.15  39.62
3.0_0.1016_71.3   1.12  0.16  12.0   3.31   0.10  71.26
9.9_0.1524_31.7   1.09  0.04  16.0   9.90   0.15  31.71
[stderr]
<string>:11: DeprecationWarning: DataFrameGroupBy.apply operated on the grouping columns. This behavior is deprecated, and in a future version of pandas the grouping columns will be excluded from the operation. Either pass `include_groups=False` to exclude the groupings or explicitly select the grouping columns after groupby to silence this warning.
Interesting. The worst conditions: - 17.4_0.0254_39.6 (high angle) rmse 3.71, bias ~0 , so it's a spread/shape issue, not bias. High angle = separated flow, different spectral shape. - 0.0_0.0254_71.3 rmse 3.0, bias -0.18 , shape issue. - 12.3_0.1016_55.5 and 12.3_0.1016_39.6: bias -1.9, -2.5 , systematic underestimate at high angle/large chord. These are high-angle (near-stall) conditions. - 6.7_0.1016_55.5: bias -1.5. So high-angle conditions (12.3, near stall) are underpredicted , the model trained mostly on lower angles can't extrapolate the stall noise increase. And high-frequency shape at angle 17.4 is hard. The bias in 12.3 conditions suggests the model needs to capture that SPL rises at high angle. Trees can't extrapolate beyond training angle range, but 12.3 is within range (train has up to 22.2). So why underpredict? Perhaps because for chord 0.1016 specifically at angle 12.3 the behavior differs, and the model averages over other chords. This is fundamentally hard. Let me think about the physics collapse approach which may generalize better. Let me examine the Strouhal collapse. Let me plot SPL vs log_strouhal and see if there's a clean master curve. Actually I can't plot, but I can fit and check residuals. Key BPM idea: Define St = f * delta* / U. The SPL - 10*log10(delta* M^5 L /r^2) collapses onto a spectral function of St/St_peak. Let me just test: can a model using primarily (log_strouhal, log_thick, log_vel, angle, log_chord) predict well? The trees already use these. Let me reconsider , maybe the issue is that trees don't capture the smooth angle dependence. Let me think about a different, more physical model: SPL = g(log_freq, angle, log_chord, log_vel, log_thick) where g is smooth. A neural net or SVR should capture smoothness but they underperformed trees. Alternatively, maybe I should engineer the Strouhal-based collapse explicitly and fit a flexible 1D+ model. Hmm, but the p90 target 2.35 is SO close to rmse target 2.25. This means they expect a model where nearly all conditions are well-predicted. Given noise floor 1.0, per-condition RMSE ~2.35 means bias/shape error ~2.1. Let me reconsider whether the noise floor is really 1.0 or if I can do better. Actually, maybe I should reconsider whether the thickness feature makes the problem much easier. delta* essentially encodes (angle, chord, velocity) boundary layer state. Let me check how predictable SPL is using a model that leverages delta* strongly. Let me actually look at the relationship: for the 12.3_0.1016 conditions, is delta* large? delta* = 0.04 (from test row af_val_0000 which is 12.3_0.1016_39.6, thickness 0.0407). That's a large thickness. High angle -> thick boundary layer -> more low-freq noise. The model underpredicts these. In training, are there conditions with thickness ~0.04? Let me check the training data coverage of high-thickness. Let me examine the joint coverage. The held-out conditions that fail might be at the edge of the training distribution. Let me step back and think strategically about time budget. I have limited tokens. Let me be efficient. Strategy: The bottleneck is per-condition worst cases on held-out conditions, especially high-angle/near-stall. A robust approach: 1. Strong ensemble (trees + boosting + SVR + MLP) for the global fit. 2. Physics features to aid extrapolation. But p90=3.3 vs target 2.35 is a big gap. I wonder if my CV/val estimate is pessimistic relative to the hidden set. The hidden set might have more conditions (so percentiles are smoother) and might be sampled to be "calibrated" nicely. Wait , re-read: "a calibrated benchmark derived from the public UCI Airfoil Self-Noise measurements." and targets are specific. The validation set is "for local tuning". The hidden test likely has similar difficulty. Actually, maybe the hidden test conditions are DIFFERENT from validation conditions. With only 15 val conditions, p90 is the 90th percentile ≈ between 13th and 14th value. My val p90 ~ …[truncated]
Let me check the interpolation ceiling (random CV vs grouped CV) to understand how much error is due to held-out conditions specifically, and which regimes are hardest.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *; from features import *
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor
from sklearn.model_selection import KFold
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=Xy(alld); condall=condition_key(alld)
# Random KFold (interpolation: conditions seen)
kf=KFold(5,shuffle=True,random_state=0); oof=np.zeros(len(yall))
for tri,tei in kf.split(Xall):
    m=ExtraTreesRegressor(n_estimators=600,max_features=0.6,n_jobs=-1,random_state=0).fit(Xall.iloc[tri],yall.iloc[tri])
    oof[tei]=m.predict(Xall.iloc[tei])
print('RANDOM KFold (interpolation):',{k:round(v,3) for k,v in metrics(yall,oof,condall).items()})
cvm,_=group_cv(lambda:ExtraTreesRegressor(n_estimators=600,max_features=0.6,n_jobs=-1,random_state=0),Xall,yall,condall.values,condall)
print('GROUP KFold (extrapolation):',{k:round(v,3) for k,v in cvm.items()})
"
output
RANDOM KFold (interpolation): {'rmse': 1.514, 'mae': 1.076, 'p90': 2.218, 'p95': 2.693, 'maxc': 3.637, 'ncond': 82}
GROUP KFold (extrapolation): {'rmse': 2.463, 'mae': 1.831, 'p90': 3.455, 'p95': 4.098, 'maxc': 5.99, 'ncond': 82}
Very informative: - Random KFold (conditions seen in training): rmse 1.51, mae 1.08, p90 2.22, p95 2.69, max 3.64. This is the interpolation ceiling. - Group KFold (held-out conditions): rmse 2.46, mae 1.83, p90 3.46, max 5.99. So the gap between interpolation and extrapolation is large. The solved targets (rmse 2.25, p90 2.35) are between these two. Interpolation already nearly meets p90 (2.22 <= 2.35). So the target requires getting close to interpolation performance , i.e., generalize to held-out conditions almost as well as interpolation. This is the crux. I need a model that extrapolates to unseen (angle, chord, velocity) combos nearly as well as interpolation. The physics structure is the key: if the SPL truly is a smooth function of physical variables, then a model capturing that structure can predict unseen conditions. The thickness delta* is the critical variable , it's a derived boundary-layer quantity that already encodes the aerodynamic condition. So maybe the right move is to rely heavily on delta* and frequency via Strouhal number, which collapses conditions. Let me test: a model using the Strouhal collapse. Let me think about what features best enable extrapolation. Let me examine the core relationship. In BPM, the TBL-TE noise: SPL = 10 log10(delta_s* * M^5 * L * D / r^2) + A(St_s) + (K1 - 3) + ... where St_s = f * delta_s* / U, M = U/c0. So SPL ≈ 10*log10(delta*) + 50*log10(U/c0) + A(St) + const + angle-dependent terms. So the base amplitude scales as 10*log10(delta*) + 50*log10(U). Wait M^5 -> 10*log10(M^5) = 50*log10(M) = 50*log10(U/c0). That's a strong velocity dependence. Let me construct: base = 10*log10(delta*) + 50*log10(U). And spectral shape A as function of log(St). Let me check if SPL - base collapses vs log(St). Actually, let me just check empirically: regress SPL on these physical features and see residual structure. But more productively, let me build features that make the collapse explicit and feed to trees/ensemble, then measure GROUP CV. Let me define St = f*delta*/U. And test feature set {log_St, log_thick, log_vel, log_chord, angle} vs current. Let me also add the BPM-like base term. Let me run a focused experiment: ExtraTrees and MLP on different physically-motivated feature sets, measuring GROUP CV metrics. Actually, the features I have already include log_strouhal, log_thick, log_vel, etc. The trees have access. The issue is trees partition and can't smoothly extrapolate the amplitude scaling. A linear/smooth model CAN extrapolate the 10log(delta*)+50log(U) scaling but can't capture the spectral shape flexibly. IDEA: Hybrid model: - Transform target by subtracting a physics baseline that captures amplitude scaling: SPL_resid = SPL - (a*log10(delta*) + b*log10(U) + ...). Fit a,b by linear regression. Then model residual (mostly spectral shape vs St) with trees. This could generalize better because the amplitude scaling extrapolates linearly. But trees on residual still need to extrapolate St shape. Hmm. Alternatively: a GAM = additive smooth functions. SPL = s1(log_St) + s2(log_thick) + s3(log_vel) + s4(angle) + s5(log_chord) + interactions. An additive spline model extrapolates each 1D function linearly at edges , more stable. Let me test SplineTransformer with interaction terms but careful. Actually the pure Spline-Ridge earlier gave rmse 3.0 (underfit , additive only, no interactions). Let me add key interactions: log_St with log_chord, log_St with angle. Let me think about what ACTUALLY drives good extrapolation here. The best approach may be a careful neural network that learns the smooth physical function. Let me invest in tuning an MLP ensemble with the physical features. MLPs interpolate smoothly and extrapolate more gracefully than trees for smooth functions. Let me do a focused experiment: 1. Physics feature set P1 = [log_freq, angle, log_chord, log_vel, log_thick, log_strouhal, log_reynolds] 2. MLP ensemble (multiple seeds, averaged) - smooth 3. Compare to tre …[truncated]
The interpolation ceiling (random CV: p90=2.22) nearly meets targets, but extrapolation (grouped: p90=3.46) doesn't. I must capture the smooth physical structure so held-out conditions behave like interpolation. Let me test the BPM Strouhal-collapse hypothesis.
bash
cd /app && python3 -c "
import pandas as pd, numpy as np
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
f=alld.frequency; a=alld.attack_angle; c=alld.chord_length; u=alld.free_stream_velocity; d=alld.suction_side_displacement_thickness
y=alld.scaled_sound_pressure_level
St=f*d/u
# BPM-ish base amplitude
base=10*np.log10(d)+50*np.log10(u/340.0)
resid=y-base
import numpy as np
# correlation of resid with log St
lSt=np.log10(St)
print('corr(y, 10log d):', np.corrcoef(y,10*np.log10(d))[0,1].round(3))
print('corr(y, 50log u):', np.corrcoef(y,50*np.log10(u))[0,1].round(3))
print('corr(resid, logSt):', np.corrcoef(resid,lSt)[0,1].round(3))
# fit resid ~ poly(logSt) and check
for deg in [2,3,4,5]:
    co=np.polyfit(lSt,resid,deg); r=resid-np.polyval(co,lSt)
    print(f'resid~poly(logSt) deg{deg}: R2={1-r.var()/resid.var():.3f} rmse={np.sqrt((r**2).mean()):.3f}')
# full: y ~ poly(logSt) deg5 + linear(10logd,50logu,angle,logc)
import numpy as np
from numpy.linalg import lstsq
X=np.column_stack([np.ones_like(y)]+[lSt**k for k in range(1,6)]+[np.log10(d),np.log10(u),a,np.log10(c)])
coef,_,_,_=lstsq(X,y,rcond=None); yp=X@coef; r=y-yp
print('y~poly5(logSt)+phys linear: rmse=%.3f mae=%.3f R2=%.3f'%(np.sqrt((r**2).mean()),np.abs(r).mean(),1-r.var()/y.var()))
"
output
corr(y, 10log d): -0.348
corr(y, 50log u): 0.085
corr(resid, logSt): -0.56
resid~poly(logSt) deg2: R2=0.346 rmse=9.691
resid~poly(logSt) deg3: R2=0.353 rmse=9.641
resid~poly(logSt) deg4: R2=0.353 rmse=9.639
resid~poly(logSt) deg5: R2=0.354 rmse=9.634
y~poly5(logSt)+phys linear: rmse=4.476 mae=3.372 R2=0.562
The simple Strouhal collapse is weak (R² ~0.35-0.56). The BPM single-Strouhal collapse isn't enough , real data needs the full model with multiple spectral mechanisms and angle-dependent separation noise. So a simple physical parametric model won't reach the target. Let me reconsider. The linear physics model gives rmse 4.5. Trees give 2.46 (group CV). The target 2.25 is below trees. So I need trees/ML but with better extrapolation. Key: reduce the worst held-out condition errors. Let me reconsider the structure. Maybe combining smooth physical features with trees in a way that helps. Or maybe a larger, more careful ensemble. Let me reconsider the gap. Group CV ET: rmse 2.46, target 2.25. Ensemble (ET+HGB+SVR+MLP) gave CV rmse 2.21 already ≤ 2.25! And mae 1.62 (target 1.55, slightly over). p90 3.25 (target 2.35, over). max 5.04 (target 5.60, OK). p95 3.79 (target 4.75, OK). So with the 4-model ensemble, on the 82-condition group CV: - rmse 2.21 ✓ (<=2.25) - mae 1.62 ✗ (need <=1.55, close) - p90 3.25 ✗ (need <=2.35, big gap) - p95 3.79 ✓ (<=4.75) - max 5.04 ✓ (<=5.60) So rmse, p95, max are OK. mae is close. p90 is the big problem. Wait , p90 <= 2.35 but p95 <= 4.75. That's a weird ordering: p90 target (2.35) is much lower than p95 target (4.75). So they allow the top 5-10% of conditions to be bad (up to 4.75 at p95, 5.60 max), but the 90th percentile must be tight (2.35). This means: at least 90% of conditions must have RMSE <= 2.35, but the worst 10% can be up to 4.75-5.60. So I need ~90% of conditions under 2.35. Currently with the ensemble, what fraction is under 2.35? p90=3.25 means 90th percentile is 3.25, so only ~75-80% are under 2.35 maybe. I need to push more conditions under 2.35. This reframes the problem: I need to reduce the number of "moderately bad" conditions (those between 2.35 and 3.5). The truly terrible ones (high angle stall) can remain up to 5.6. So the focus: improve the bulk of held-out conditions to be under 2.35 RMSE. Given interpolation gets p90 2.22, it's achievable if extrapolation is good enough. Let me look at the distribution of per-condition RMSE for the ensemble in group CV , how many are between 2.35 and 3.25? Let me compute the full sorted per-condition RMSE for the best ensemble in group CV. This tells me exactly where I stand. Let me build the ensemble OOF and examine.
The simple physics collapse is too weak (R²≈0.35). The reframing is key: **p90≤2.35 but p95≤4.75** means ~90% of conditions must be tight while the worst 10% can be loose. Let me examine the full per-condition RMSE distribution for the best ensemble under grouped CV.
bash
cd /app && cat > /tmp/ens_oof.py << 'EOF'
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *; from features import *
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, ExtraTreesRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import GroupKFold

alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=Xy(alld); condall=condition_key(alld); groups=condall.values

def makers():
    return [
     ('ET',lambda: ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=0)),
     ('HGB',lambda: HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0)),
     ('SVR',lambda: make_pipeline(StandardScaler(),SVR(C=30,gamma='scale',epsilon=0.05))),
     ('MLP',lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=3000,alpha=1e-3,random_state=0))),
    ]

gkf=GroupKFold(5)
oofs={n:np.zeros(len(yall)) for n,_ in makers()}
for tri,tei in gkf.split(Xall,yall,groups):
    for n,mk in makers():
        m=mk().fit(Xall.iloc[tri],yall.iloc[tri]); oofs[n][tei]=m.predict(Xall.iloc[tei])
ens=np.mean([oofs[n] for n,_ in makers()],axis=0)
m=metrics(yall,ens,condall)
print('ENSEMBLE group CV:',{k:round(v,3) for k,v in m.items()})
# per-condition rmse distribution
dfm=pd.DataFrame({'c':condall.values,'e':ens-yall.values})
cr=dfm.groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2))).sort_values()
print('num conditions:',len(cr))
print('frac <=2.35:',(cr<=2.35).mean().round(3))
print('count in (2.35,3.5]:',((cr>2.35)&(cr<=3.5)).sum())
print('worst 12:'); print(cr.tail(12).round(2).to_string())
np.save('/tmp/oof_ens.npy',ens); np.save('/tmp/yall.npy',yall.values)
EOF
python3 /tmp/ens_oof.py
output
ENSEMBLE group CV: {'rmse': 2.209, 'mae': 1.62, 'p90': 3.252, 'p95': 3.791, 'maxc': 5.036, 'ncond': 82}
num conditions: 82
frac <=2.35: 0.72
count in (2.35,3.5]: 16
worst 12:
c
8.9_0.0508_55.5     2.82
8.9_0.1016_71.3     2.97
4.0_0.0508_71.3     3.10
12.6_0.1524_71.3    3.27
15.6_0.1016_71.3    3.28
12.3_0.1016_71.3    3.55
17.4_0.0254_31.7    3.56
17.4_0.0254_39.6    3.80
7.3_0.2286_71.3     3.92
19.7_0.0508_71.3    4.14
22.2_0.0254_39.6    4.91
12.6_0.1524_39.6    5.04
Now I have clarity: - 72% of conditions are <=2.35. I need 90%. - 16 conditions are in (2.35, 3.5]. These are the "moderately bad" ones I need to fix. - The worst are high-angle (17.4, 19.7, 22.2, 12.6) and high-velocity (71.3) conditions. To get p90<=2.35, I need ~90% (74 of 82) under 2.35. Currently 59 of 82 (72%). I need ~15 more conditions to drop under 2.35. Many of the worst are at velocity 71.3 and high angles. These are extrapolation-hard. Let me think about what would systematically help the "moderately bad" conditions (2.35-3.5). These aren't catastrophic; they're conditions where the model is a bit off. Better features or better smoothing could help. Let me reconsider the high-velocity (71.3) problem. Many bad conditions are at 71.3 m/s (the max velocity). Trees can't extrapolate the velocity scaling beyond 71.3, but 71.3 IS in the training range. However, when a whole condition at 71.3 is held out, the model must interpolate from other velocities. The velocity scaling (50*log10(U) in BPM) is smooth and should interpolate fine. But trees might not. Idea: incorporate the physical velocity scaling explicitly. Actually, the issue: when holding out a condition, e.g., (8.9, 0.0508, 55.5), the training set still has (8.9, 0.0508, 31.7), (8.9, 0.0508, 39.6), (8.9, 0.0508, 71.3)? NO , the grouping holds out by (angle, chord, velocity). But does it also hold out (8.9, 0.0508, *) for all velocities? No, only the specific tuple. So other velocities at same (angle,chord) ARE in training. So the model can interpolate across velocity. Wait, but in GroupKFold, each fold holds out a random set of conditions. The related conditions (same angle,chord, different velocity) are likely in training. So interpolation across velocity should be possible IF the model uses velocity smoothly. Let me test: does adding stronger velocity features help? Or is the problem the spectral shape? Let me look at WHY specific conditions fail. Let me examine (12.6_0.1524_39.6) , worst at 5.04. And (8.9_0.0508_55.5) at 2.82. Actually, let me take a more productive path: systematically improve the model. Let me try: 1. Better/more features (add more interactions, maybe Mach, Reynolds variants). 2. Try stacking instead of simple averaging. 3. Increase ensemble diversity with multiple seeds and bootstraps , reduces variance on moderate conditions. Actually, variance reduction via more ensemble members and seeds directly reduces per-condition RMSE for the "moderate" conditions (where error is variance, not bias). Let me check: are the moderate conditions bias-dominated or variance-dominated? Let me examine bias vs rmse for the worst conditions. Earlier for ET on val: 12.3_0.1016 had bias -1.9 to -2.5 (bias-dominated). 17.4_0.0254_39.6 had bias 0.04 (variance/shape-dominated). For bias-dominated conditions, ensembling same-type models won't help; need better features/structure. For variance/shape, more trees/smoothing helps. Let me think about the bias in high-angle large-chord conditions (12.3_0.1016 underpredicted). The model underpredicts noise at high angle. Why? Because at angle 12.3 with chord 0.1016, there's likely separation noise (higher SPL). If training has angle 12.3 at other chords and other angles at chord 0.1016, the model should interpolate. Unless the interaction angle×chord is strong and undersampled. Let me add explicit angle×chord, angle×velocity interactions and thickness-based features. Actually trees already model interactions. Hmm. Let me reconsider: maybe the thickness feature is THE key. delta* encodes the separation state. At high angle, delta* is large. Let me check if the model properly uses delta*. The bias might come from delta* for held-out high-angle conditions being outside the training delta* range for that chord. Let me take a step back and just try to maximize performance empirically with: 1. More features. 2. Multi-seed bagged ensemble of ET + HGB + MLP + SVR. 3. Maybe a stacking meta-learner. Let me test whe …[truncated]
Now it's crystal clear: **72% of conditions are ≤2.35; I need ~90%**. 16 "moderately bad" conditions (2.35–3.5), mostly high-angle/high-velocity, must be pulled under 2.35. Let me expand the physics feature set and test impact on the grouped-CV p90.
bash
cd /app && cat > /tmp/features2.py << 'EOF'
import numpy as np, pandas as pd
def make_features(df):
    f=df['frequency'].astype(float).values; a=df['attack_angle'].astype(float).values
    c=df['chord_length'].astype(float).values; u=df['free_stream_velocity'].astype(float).values
    d=df['suction_side_displacement_thickness'].astype(float).values
    lf=np.log10(f); ld=np.log10(d); lc=np.log10(c); lu=np.log10(u)
    nu=1.5e-5
    o={}
    o['log_freq']=lf; o['attack_angle']=a; o['log_chord']=lc; o['log_vel']=lu; o['log_thick']=ld
    o['log_St_d']=np.log10(f*d/u)       # displacement-thickness Strouhal
    o['log_St_c']=np.log10(f*c/u)       # chord Strouhal
    o['log_Re_c']=np.log10(c*u/nu)      # chord Reynolds
    o['log_Re_d']=np.log10(d*u/nu)      # thickness Reynolds
    o['mach']=u/340.0
    o['d_over_c']=d/c                    # relative BL thickness
    o['log_d_over_c']=np.log10(d/c)
    # interactions
    o['lf_angle']=lf*a; o['lf_ld']=lf*ld; o['lf_lc']=lf*lc; o['lf_lu']=lf*lu
    o['a_ld']=a*ld; o['a_lc']=a*lc; o['a_lu']=a*lu
    o['lf2']=lf*lf; o['angle2']=a*a; o['ld2']=ld*ld
    o['raw_freq']=f; o['raw_thick']=d
    o['sin_a']=np.sin(np.radians(a))
    return pd.DataFrame(o,index=df.index)
def Xy(df):
    return make_features(df), df['scaled_sound_pressure_level']
EOF
python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, ExtraTreesRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=F.Xy(alld); condall=condition_key(alld); groups=condall.values
makers=[
 lambda: ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=0),
 lambda: HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0),
 lambda: make_pipeline(StandardScaler(),SVR(C=30,gamma='scale',epsilon=0.05)),
 lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=3000,alpha=1e-3,random_state=0)),
]
gkf=GroupKFold(5); oofs=[np.zeros(len(yall)) for _ in makers]
for tri,tei in gkf.split(Xall,yall,groups):
    for i,mk in enumerate(makers):
        oofs[i][tei]=mk().fit(Xall.iloc[tri],yall.iloc[tri]).predict(Xall.iloc[tei])
ens=np.mean(oofs,axis=0)
m=metrics(yall,ens,condall)
print('ENS richfeat group CV:',{k:round(v,3) for k,v in m.items()})
cr=pd.DataFrame({'c':condall.values,'e':ens-yall.values}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
print('frac<=2.35:',(cr<=2.35).mean().round(3))
"
output
ENS richfeat group CV: {'rmse': 2.176, 'mae': 1.594, 'p90': 3.352, 'p95': 3.646, 'maxc': 4.928, 'ncond': 82}
frac<=2.35: 0.744
Richer features helped rmse (2.18), mae (1.59), p95 (3.65), max (4.93) but p90 still 3.35 and frac<=2.35 only 74%. The p90 is stubborn. I need a different strategy to pull the moderate conditions under 2.35. Let me reconsider the problem. Maybe the condition definition the grader uses is different from mine, giving different per-condition groupings. But I should optimize my proxy. Key realization: p90 across 82 conditions = the 8th worst condition's RMSE (since 90th percentile of 82 ≈ index 73-74, so ~8 conditions above). To get p90<=2.35, I need at most ~8 conditions above 2.35, i.e., 74+ under 2.35. Currently 61 under (74%). Need 13 more. This is a big ask. Let me think about whether the hidden test might be easier/different. The validation set (15 conditions) is my closest proxy to the hidden test. On validation, the ET model got p90 ~2.97. Let me check the ensemble on validation specifically (train→val), and the fraction under 2.35. Actually the hidden test is a separate holdout. The relationship between my CV and the hidden metric is uncertain. The grader's condition grouping might aggregate differently (maybe coarser → fewer, larger conditions → more stable percentiles, OR the exact noisy tuple → each row its own condition). WAIT. This is important. Re-read: "a condition is the tuple (attack_angle, chord_length, free_stream_velocity)". If the grader uses the EXACT float tuple, then since features are noisy, every row has a unique tuple → each condition = 1 row → per-condition RMSE = |error| of single row → p90_condition_rmse = 90th percentile of absolute errors! And max_condition_rmse = max absolute error. Hmm, but that contradicts "holds out complete aerodynamic condition groups" which implies groups with multiple rows. But the held-out grouping was done on the TRUE (pre-noise) values presumably. The grader computing per-condition RMSE would need to group rows, but if tuples are unique due to noise, grouping fails. Let me reconsider. The grader says it "recomputes metrics from your predictions and hidden labels". It computes hidden_p90_condition_rmse. For this to be meaningful (RMSE over multiple rows), conditions must group multiple rows. So the grader must snap/round the noisy features to recover conditions, OR the hidden features are NOT noisy (the true grid values), OR the hidden label file includes a condition id. Given the hidden features use "the same schema" (sample_id + 5 features), there's no explicit condition column. So the grader must derive conditions from features. It likely rounds them. Actually, maybe in the hidden set, the features are on the clean grid (not noisy), OR the grader rounds. Either way, my snapping-based grouping is a reasonable proxy. But here's a thought: if the grader rounds angle to, say, nearest 0.5 or integer, and chord/velocity to canonical, then conditions group similarly to mine. My grouping gave 82 conditions over 1157 rows (avg 14 rows). That matches the UCI structure (frequency sweeps). Let me not overthink the grader's exact grouping. Let me assume it's similar to mine and optimize for robust per-condition performance. Given the difficulty of p90<=2.35, let me reconsider if there's a better modeling paradigm. The interpolation result (random CV) gave p90=2.22. So IF I could make held-out conditions behave like interpolation, I'd pass. The difference is the model sees the condition during interpolation. Semi-supervised idea: The hidden test features ARE available at predict time (the grader stages them). I can use the test features (unlabeled) to inform the model! Transductive learning. For example: - I know the test conditions' feature values (frequency sweeps). - I can't use labels, but I can use the structure. But more powerful: since each test condition is a frequency sweep at a fixed (angle, chord, velocity), and the spectral shape is smooth in frequency, I could enforce smoothness within each test condition. E.g., fit the model, then smooth predictions …[truncated]
A key insight: the target is smooth in frequency within each condition, and at predict time I have each test condition's full frequency sweep. I can **smooth predictions across frequency within each condition** to remove model jitter (variance) , directly lowering per-condition RMSE. Let me test this on the grouped-CV out-of-fold predictions.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp')
from cv_harness import *
import pandas as pd, numpy as np
ens=np.load('/tmp/oof_ens.npy'); yall=np.load('/tmp/yall.npy')
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
cond=condition_key(alld).values; lf=np.log10(alld.frequency.values)
print('RAW ENS:',{k:round(v,3) for k,v in metrics(yall,ens,cond).items()})
def smooth(pred, deg):
    out=pred.copy()
    for c in np.unique(cond):
        idx=np.where(cond==c)[0]
        if len(idx)<deg+2: continue
        x=lf[idx]; y=pred[idx]; co=np.polyfit(x,y,min(deg,len(idx)-1)); out[idx]=np.polyval(co,x)
    return out
for deg in [2,3,4,5]:
    sm=smooth(ens,deg)
    m=metrics(yall,sm,cond)
    cr=pd.DataFrame({'c':cond,'e':sm-yall}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'SMOOTH deg{deg}:',{k:round(v,3) for k,v in m.items()},'frac<=2.35:',round((cr<=2.35).mean(),3))
"
output
RAW ENS: {'rmse': 2.209, 'mae': 1.62, 'p90': 3.252, 'p95': 3.791, 'maxc': 5.036, 'ncond': 82}
SMOOTH deg2: {'rmse': 2.43, 'mae': 1.828, 'p90': 3.353, 'p95': 4.129, 'maxc': 5.135, 'ncond': 82} frac<=2.35: 0.622
SMOOTH deg3: {'rmse': 2.299, 'mae': 1.688, 'p90': 3.191, 'p95': 4.153, 'maxc': 5.276, 'ncond': 82} frac<=2.35: 0.695
SMOOTH deg4: {'rmse': 2.26, 'mae': 1.657, 'p90': 3.252, 'p95': 3.937, 'maxc': 5.102, 'ncond': 82} frac<=2.35: 0.707
SMOOTH deg5: {'rmse': 2.235, 'mae': 1.64, 'p90': 3.227, 'p95': 3.933, 'maxc': 5.042, 'ncond': 82} frac<=2.35: 0.72
Polynomial smoothing doesn't help (even hurts at low degree because it imposes too rigid a shape that adds bias). The model predictions aren't jittery enough across frequency for smoothing to help; the errors are more systematic (bias in the curve level/shape). So the problem is bias, not variance. So the issue is the model systematically mispredicts entire conditions. That's a harder problem requiring better extrapolation of the condition-level behavior. Let me reconsider. Since errors are bias-dominated per condition, I need the model to get the overall level right for held-out conditions. Let me look at this from a different angle. What if I use the transductive information differently: the test features tell me the test conditions. The displacement thickness delta* is a deterministic function of (angle, chord, velocity) in the original data. For a held-out condition, delta* is given in the features. So delta* provides strong info about the condition's boundary layer state even though (angle,chord,velocity) combo is unseen. The model already uses delta*. But maybe the relationship SPL-vs-features has structure I can exploit. Let me reconsider the level/bias issue. For each condition, the "level" (mean SPL offset) is what's mispredicted. Let me see if I can predict the condition-level mean better. Actually, let me reconsider whether the problem is really that hard, or if my CV is overly pessimistic. Let me focus on the actual validation set (the designated local tuning proxy, 15 conditions) and see the real numbers for the best ensemble. The hidden set is probably most similar to validation in construction. Let me compute the ensemble train→val metrics with rich features. Earlier (bench2) ET+HGB+SVR+MLP on val gave rmse 2.284, mae 1.811, p90 3.25, p95 3.45, max 3.54. With rich features let me recompute. Val p90 3.25 is the issue. Hmm. But wait , on validation, max was only 3.54 (well under 5.60), p95 3.45 (under 4.75). Only p90 (3.25) exceeds 2.35, and mae (1.81) exceeds 1.55, rmse (2.28) slightly over 2.25. The val set has 15 conditions; p90 = ~90th percentile ≈ 2nd worst of 15. So I need the 2nd-worst condition <= 2.35. That's demanding. Let me think hard about reducing per-condition bias. Approach: Quantile/robust aggregation won't fix bias. Better features or model structure will. Let me reconsider the BPM physics. Self-noise has multiple mechanisms: 1. TBL-TE (turbulent boundary layer - trailing edge): dominant at low angles. 2. Separation-stall noise: dominant at high angles. 3. LBL-VS (laminar BL vortex shedding): low Reynolds. 4. TE bluntness. Each has different scaling. The transition between regimes (especially stall at high angle) causes the model trouble. The high-angle conditions (12.3+, chord-dependent stall) are where bias appears. One idea: separate models or features for stall regime. But that's complex. Let me try a fundamentally stronger single approach: Gaussian Process Regression with a physically-scaled kernel could give smooth extrapolation with good uncertainty. But GP on 1157 points is feasible (O(n³) ~ 1.5e9, doable). Let me try GP with RBF+linear kernel on scaled physical features. GP extrapolates smoothly and might handle held-out conditions better. Actually, let me reconsider my approach to be more systematic about reducing the moderately-bad conditions. Let me try: 1. A much bigger, more diverse ensemble: ET (multiple seeds/params), RF, HGB (multiple), GB, SVR, MLP (multiple seeds), KNN, KernelRidge, GP. Average them. Diversity reduces both variance and some bias. 2. Weight the ensemble to minimize CV p90. Let me test a GP and KernelRidge first, since smooth models might nail the level better. Let me test additional base learners on group CV.
Smoothing doesn't help , errors are **bias-dominated per condition**, not jitter. I need models that extrapolate the condition level better. Let me test smooth global learners (Gaussian Process, KernelRidge) and more diverse trees to add to the ensemble.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.kernel_ridge import KernelRidge
from sklearn.gaussian_process import GaussianProcessRegressor
from sklearn.gaussian_process.kernels import RBF, WhiteKernel, ConstantKernel, DotProduct, Matern
from sklearn.ensemble import RandomForestRegressor, GradientBoostingRegressor
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=F.Xy(alld); condall=condition_key(alld); groups=condall.values
def ev(name,make):
    cvm,_=group_cv(make,Xall,yall,groups,condall,5)
    print(f'{name:22s} CV rmse={cvm[\"rmse\"]:.3f} mae={cvm[\"mae\"]:.3f} p90={cvm[\"p90\"]:.2f} p95={cvm[\"p95\"]:.2f} max={cvm[\"maxc\"]:.2f}')
ev('KernelRidge rbf', lambda: make_pipeline(StandardScaler(),KernelRidge(alpha=0.1,kernel='rbf',gamma=0.05)))
ev('KernelRidge rbf2', lambda: make_pipeline(StandardScaler(),KernelRidge(alpha=0.3,kernel='rbf',gamma=0.1)))
k=ConstantKernel(1.0)*Matern(length_scale=np.ones(Xall.shape[1]),nu=2.5)+WhiteKernel(0.5)
ev('GP Matern-ARD', lambda: make_pipeline(StandardScaler(),GaussianProcessRegressor(kernel=k,alpha=1e-6,normalize_y=True,n_restarts_optimizer=0)))
ev('RF tuned', lambda: RandomForestRegressor(n_estimators=600,max_features=0.5,min_samples_leaf=2,n_jobs=-1,random_state=0))
ev('GB', lambda: GradientBoostingRegressor(n_estimators=500,learning_rate=0.03,max_depth=3,subsample=0.8,random_state=0))
"
output
[stderr]
KernelRidge rbf        CV rmse=8.678 mae=4.679 p90=9.16 p95=15.07 max=53.81
KernelRidge rbf2       CV rmse=16.588 mae=9.835 p90=18.77 p95=35.88 max=83.77Shell command timed out.
Tool interaction exceeded 300 seconds.
KernelRidge with those gammas is terrible (overfit/underfit), and GP with ARD is too slow (timed out). Let me restart the tool and avoid GP ARD (too slow) and bad KRR. Let me be more careful and faster. Let me restart and focus. The tree ensemble is the workhorse. Let me focus on: 1. Tuning KernelRidge properly (it can be good with right gamma/alpha). 2. A faster GP (single length scale, no restarts) or skip GP. 3. Building the final robust ensemble. Actually KernelRidge RBF needs proper gamma. gamma=0.05 gave rmse 8.7 (bad). The features have ~26 dims; default gamma=1/n_features~0.04. The issue might be that some features (raw_freq ~ thousands) aren't scaled well , but StandardScaler handles that. rmse 8.7 is way off, suggesting gamma too large causing near-interpolation overfit that fails on held-out groups. Let me try much smaller gamma and larger alpha. Let me restart.
bash
restart: true
output
<system>tool has been restarted.</system>
bash
cd /app && timeout 250 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.kernel_ridge import KernelRidge
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=F.Xy(alld); condall=condition_key(alld); groups=condall.values
def ev(name,make):
    cvm,_=group_cv(make,Xall,yall,groups,condall,5)
    print(f'{name:22s} CV rmse={cvm[\"rmse\"]:.3f} mae={cvm[\"mae\"]:.3f} p90={cvm[\"p90\"]:.2f} p95={cvm[\"p95\"]:.2f} max={cvm[\"maxc\"]:.2f}')
for g,a in [(0.01,0.1),(0.02,0.5),(0.03,1.0),(0.05,2.0)]:
    ev(f'KRR g{g} a{a}', lambda g=g,a=a: make_pipeline(StandardScaler(),KernelRidge(alpha=a,kernel='rbf',gamma=g)))
"
output
KRR g0.01 a0.1         CV rmse=3.573 mae=2.423 p90=4.28 p95=5.23 max=18.40
KRR g0.02 a0.5         CV rmse=5.631 mae=3.602 p90=6.85 p95=8.99 max=30.92
KRR g0.03 a1.0         CV rmse=8.051 mae=5.160 p90=9.61 p95=14.33 max=41.72
KRR g0.05 a2.0         CV rmse=13.062 mae=8.558 p90=17.76 p95=26.36 max=59.08
KernelRidge is consistently bad here , the RBF kernel with many features overfits to training groups and fails on held-out conditions with huge max errors (18-59!). The raw_freq and raw_thick features likely cause issues. KRR is not suitable. Let me drop KRR and GP. Let me refocus. The tree ensemble (ET+HGB+SVR+MLP) with rich features is my best: CV rmse 2.18, mae 1.59, p90 3.35, p95 3.65, max 4.93. The fundamental challenge is p90. Let me reconsider the whole framing once more. Actually , maybe I'm overcomplicating. Let me reconsider the grader's condition definition. What if the grader's "condition" grouping produces FEWER, larger groups than mine (e.g., it ignores the noise and groups by something coarser), making per-condition RMSE more stable and the p90 easier? Or what if the hidden test set is constructed so that per-condition groups are large? I genuinely don't know the grader's grouping. But my job is to minimize per-condition errors robustly. Let me assume my proxy is reasonable and push hard. Let me reconsider the bias problem with a concrete plan: The per-condition bias means the model gets the LEVEL of a held-out condition wrong. To fix levels, I should ensure the model captures the main level-driving physics: delta* and velocity and angle. Let me test an idea: Add the condition-level mean as a target-encoded-like feature is leakage. No. Alternative: Use a model that directly predicts well. Let me reconsider , maybe the MLP, properly tuned and ensembled over many seeds, gives smooth level predictions that generalize. Let me test a bagged MLP ensemble (10 seeds) alone on group CV. And a bagged ET with more trees. Actually, the best lever for bias on held-out conditions might be feature selection , removing features that cause overfitting to specific conditions (like raw_freq, raw_thick which let trees memorize). Let me test dropping raw features. Let me also reconsider: maybe fewer, more physical features generalize better for the smooth models. Let me test the ensemble with a leaner feature set. Let me run a focused experiment: the 4-model ensemble with (a) rich features, (b) lean physical features, (c) rich minus raw. Measure group CV. Keep it fast (precompute OOF per model, combine). Let me time-box to ~200s. Actually, let me reconsider the SVR contribution , SVR had max 8.36 earlier (unstable). MLP is smooth. Let me build the OOF matrix for a set of candidate base learners ONCE, then experiment with combinations/weights cheaply. This is efficient. Let me compute OOF for: ET, HGB, MLPx3seeds, SVR, RF, GB on rich features. Save OOF matrix. Then explore combos. Let me do it in the background to avoid timeout, writing results to a file. Let me write a script that computes OOF for several learners and saves to npz.
KernelRidge/GP are unstable here (huge max errors). Let me precompute grouped-CV out-of-fold predictions for a diverse set of base learners once, save them, then cheaply explore ensemble combinations. I'll run it in the background to avoid timeouts.
bash
cd /app && cat > /tmp/make_oof.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, ExtraTreesRegressor, RandomForestRegressor, GradientBoostingRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import GroupKFold

alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=F.Xy(alld); cond=condition_key(alld); groups=cond.values
Xnr=Xall.drop(columns=['raw_freq','raw_thick'])

learners={
 'ET': (Xall, lambda: ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=0)),
 'ETnr': (Xnr, lambda: ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=1)),
 'HGB': (Xall, lambda: HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0)),
 'RF': (Xall, lambda: RandomForestRegressor(n_estimators=600,max_features=0.5,min_samples_leaf=2,n_jobs=-1,random_state=0)),
 'GB': (Xnr, lambda: GradientBoostingRegressor(n_estimators=500,learning_rate=0.03,max_depth=3,subsample=0.8,random_state=0)),
 'SVR': (Xnr, lambda: make_pipeline(StandardScaler(),SVR(C=30,gamma='scale',epsilon=0.05))),
 'MLP0': (Xnr, lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=3000,alpha=1e-3,random_state=0))),
 'MLP1': (Xnr, lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(200,100),max_iter=3000,alpha=3e-3,random_state=1))),
 'MLP2': (Xnr, lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=3000,alpha=1e-3,random_state=2))),
}
gkf=GroupKFold(5)
splits=list(gkf.split(Xall,yall,groups))
oof={}
for name,(Xd,mk) in learners.items():
    p=np.zeros(len(yall))
    for tri,tei in splits:
        p[tei]=mk().fit(Xd.iloc[tri],yall.iloc[tri]).predict(Xd.iloc[tei])
    oof[name]=p
    m=metrics(yall,p,cond)
    print(f'{name:6s} rmse={m["rmse"]:.3f} mae={m["mae"]:.3f} p90={m["p90"]:.2f} p95={m["p95"]:.2f} max={m["maxc"]:.2f}',flush=True)
np.savez('/tmp/oof_all.npz', y=yall.values, cond=cond.values, **oof)
print('DONE')
EOF
nohup python3 /tmp/make_oof.py > /tmp/oof_log.txt 2>&1 &
echo "started pid $!"
output
started pid 887
While that runs, let me think more about the strategy. Let me wait and check the log.
bash
sleep 60 && cat /tmp/oof_log.txt
output
ET     rmse=2.369 mae=1.745 p90=3.39 p95=4.02 max=5.44
ETnr   rmse=2.407 mae=1.775 p90=3.37 p95=3.99 max=5.63
HGB    rmse=2.422 mae=1.774 p90=3.67 p95=4.05 max=5.33
bash
sleep 75 && cat /tmp/oof_log.txt
output
ET     rmse=2.369 mae=1.745 p90=3.39 p95=4.02 max=5.44
ETnr   rmse=2.407 mae=1.775 p90=3.37 p95=3.99 max=5.63
HGB    rmse=2.422 mae=1.774 p90=3.67 p95=4.05 max=5.33
RF     rmse=2.609 mae=1.946 p90=3.88 p95=4.38 max=5.50
GB     rmse=2.700 mae=2.006 p90=3.94 p95=4.32 max=8.78
SVR    rmse=2.856 mae=1.999 p90=3.93 p95=4.89 max=8.74
MLP0   rmse=3.086 mae=2.281 p90=4.44 p95=4.80 max=9.60
MLP1   rmse=2.800 mae=2.117 p90=3.97 p95=4.48 max=7.54
MLP2   rmse=2.896 mae=2.192 p90=4.19 p95=4.90 max=7.37
DONE
Now I have OOF for all learners. Individually, ET is best (rmse 2.37). The MLPs are noticeably worse now (dropping raw features hurt them?) , MLP0 rmse 3.09. SVR and GB have high max (8+). Wait, these individual numbers are a bit worse than before because I changed feature sets (MLP/SVR on Xnr which drops raw features). Earlier MLP in the full ensemble was on Xall (rich). Let me note MLPs here are weaker. Let me now explore ensemble combinations on the saved OOF to find the combo minimizing p90 (and keeping mae/rmse under target). Let me do a search. Actually, the fundamental issue persists: even the best individual (ET p90 3.39) and ensembles (~3.25) are far from p90 2.35. Averaging similar models reduces variance but the bias-dominated conditions remain. I keep hitting the wall that ~26% of conditions have RMSE > 2.35 due to systematic bias on held-out physical regimes. Let me step back and reconsider the problem from scratch. Is there something about the data generation I'm missing that would let a model generalize much better? The target is "calibrated". Let me reconsider: maybe the calibration is a smooth monotonic transform of a physics model, and the features map cleanly. Let me check if there's a cleaner functional form. Actually, let me reconsider the noise floor. I estimated ~1.0 within-condition. But between conditions, the held-out condition LEVEL must be predicted. If the calibrated target has condition-level noise (a random offset per condition added during calibration), then NO model could predict held-out condition levels better than that noise , making the target unachievable by design unless the offset is small. Let me check: is there condition-level structure? Let me look at whether the within-condition smooth fit residual (1.0) plus between-condition predictable-ness explains things. Hmm, let me reconsider. Let me directly test the best POSSIBLE per-condition prediction: if I fit a model on ALL data (including the condition) how low does per-condition RMSE go? That's the noise floor including condition level. The random-CV gave p90 2.22, which includes condition level being learnable (since random CV has same conditions in train). So condition levels ARE learnable to p90 2.22. Good , no huge per-condition offset noise. So the target IS achievable in principle; I just need better extrapolation. Let me reconsider: what makes random-CV work (p90 2.22) that grouped-CV lacks? In random CV, each condition has ~11 of its ~14 rows in training (the sweep), so the model learns the condition's level/shape directly. In grouped CV, the condition is entirely absent. To bridge this: I need the model to infer the condition's level/shape from (angle, chord, velocity, delta*) alone. The delta* feature is the key bridge because it's condition-specific and physically meaningful. KEY IDEA: In the original UCI data, delta* is a DETERMINISTIC function of (angle, chord, velocity). So for a held-out condition, the delta* value is a strong, possibly near-unique identifier of the boundary-layer state. If SPL depends primarily on (frequency, delta*, velocity) , with angle/chord only acting through delta* , then held-out conditions with a given delta* behave like training conditions with similar delta*. This would generalize well! Let me test this hypothesis: model SPL using ONLY (frequency, delta*, velocity) features (+ derived St, Re). If angle and chord add little beyond delta*, then a model without them might generalize BETTER (less overfitting to specific angle/chord combos) and interpolate via delta*. Let me test feature sets: - S1: [log_freq, log_thick, log_vel] + [log_St_d, log_Re_d, mach] (no angle, no chord) - S2: S1 + angle - S3: full Let me quickly test ET on these via group CV. Let me run this test.
I have OOF for all learners. Now a crucial hypothesis: in the UCI data, `δ*` is a deterministic function of (angle, chord, velocity), so it may be a sufficient statistic for the boundary-layer state. Modeling SPL via (frequency, δ*, velocity) , dropping angle/chord , might **generalize better** to unseen angle/chord combos. Let me test feature-subset generalization.
bash
cd /app && timeout 250 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
cond=condition_key(alld); y=alld['scaled_sound_pressure_level']
f=alld.frequency.values; a=alld.attack_angle.values; c=alld.chord_length.values
u=alld.free_stream_velocity.values; d=alld.suction_side_displacement_thickness.values
lf=np.log10(f); ld=np.log10(d); lc=np.log10(c); lu=np.log10(u)
feats={
 'freq,d,U(+St,Re)': np.column_stack([lf,ld,lu,np.log10(f*d/u),np.log10(d*u/1.5e-5),u/340]),
 '+angle': np.column_stack([lf,ld,lu,np.log10(f*d/u),np.log10(d*u/1.5e-5),u/340,a]),
 '+angle+chord': np.column_stack([lf,ld,lu,lc,np.log10(f*d/u),np.log10(f*c/u),np.log10(d*u/1.5e-5),np.log10(c*u/1.5e-5),u/340,a]),
 'no_thick(a,c,U,f)': np.column_stack([lf,a,lc,lu,np.log10(f*c/u),np.log10(c*u/1.5e-5)]),
}
for name,Xm in feats.items():
    Xd=pd.DataFrame(Xm)
    cvm,_=group_cv(lambda:ExtraTreesRegressor(n_estimators=600,max_features=0.7,n_jobs=-1,random_state=0),Xd,y,cond.values,cond,5)
    cr=pd.DataFrame({'c':cond.values,'e':_-y.values}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'ET [{name:22s}] rmse={cvm[\"rmse\"]:.3f} mae={cvm[\"mae\"]:.3f} p90={cvm[\"p90\"]:.2f} p95={cvm[\"p95\"]:.2f} max={cvm[\"maxc\"]:.2f} frac<=2.35={ (cr<=2.35).mean():.2f}')
"
output
ET [freq,d,U(+St,Re)      ] rmse=4.148 mae=3.195 p90=6.22 p95=7.30 max=7.68 frac<=2.35=0.24
ET [+angle                ] rmse=2.944 mae=2.315 p90=4.28 p95=4.56 max=4.98 frac<=2.35=0.39
ET [+angle+chord          ] rmse=2.398 mae=1.795 p90=3.51 p95=3.93 max=5.52 frac<=2.35=0.62
ET [no_thick(a,c,U,f)     ] rmse=2.927 mae=2.191 p90=4.05 p95=5.02 max=7.38 frac<=2.35=0.45
Interesting and important: - Using only (freq, d, U) WITHOUT angle/chord is MUCH WORSE (rmse 4.15). So delta* is NOT a sufficient statistic , angle and chord carry independent info. My hypothesis was wrong. - Adding angle helps, adding chord helps more. Full (+angle+chord) is best (rmse 2.40). - Dropping thickness (no_thick) is worse (2.93). So thickness IS important too. So all features matter. The full feature set is needed. Good to confirm. So I'm back to: the rich-feature ensemble (~rmse 2.18, p90 3.35) is near the best, and p90 is the wall. Let me reconsider the achievability. The interpolation p90 is 2.22. Grouped is 3.35. The target 2.35 sits much closer to interpolation. Let me reconsider whether the hidden test will have the SAME difficulty as my grouped CV. My grouped CV holds out random conditions. But the actual train/val/hidden split was done ONCE with specific conditions. The validation set is the official "local tuning" proxy. Let me look very carefully at the validation performance, because the hidden set is likely constructed the same way as validation (same split procedure). Let me reconsider , the key question: are the validation conditions "easier" than random grouped CV? The official split might deliberately make validation/hidden representative. Let me compute the best ensemble's metrics specifically on the official validation set (train→val), with full rich features and the full ensemble, to see the real target-relevant numbers. Actually, I realize I should reconsider the possibility that the grader groups conditions more coarsely, OR that the per-condition metric is computed over larger groups making it more forgiving. But let me focus on what I can control: get the best model, and evaluate on the official validation split as the primary proxy (since it's the designated local proxy and most similar to hidden). Let me compute the full ensemble (ET+ETnr+HGB+RF on rich features, which are the strong ones; maybe add MLP/SVR lightly) on train→val, and also do repeated grouped CV to estimate variance. Actually, let me reconsider the ensemble weights using the saved OOF to directly optimize for the metrics. Let me load OOF and search weighted combos minimizing a composite. But I should validate on the official val split too. Hmm, but the OOF I saved is from grouped CV over all data (train+val). The official val split is a subset. Let me just also generate train→val predictions for each learner to evaluate on the official 15 conditions. Let me be strategic. Let me reconsider the entire approach given the difficulty. Perhaps I'm over-indexing on p90 from a pessimistic proxy. Let me reconsider: maybe the GRADER's per-condition grouping uses the TRUE underlying condition (without noise) and the hidden set has MANY rows per condition (large frequency sweeps), making per-condition RMSE stable. If a condition has 14 rows and the model has bias b and noise s, per-condition RMSE ≈ sqrt(b² + s²). With s~1.0 (noise floor) and typical bias... Let me just try to push the model as hard as I can and measure on BOTH the official val split AND grouped CV. Let me build the best ensemble and get honest numbers on the official validation. Let me also try one more modeling idea that could genuinely help bias: a two-stage approach where I first fit trees, then correct per-condition level using a smooth model of the residual vs physical features. Probably won't help bias either. Let me get concrete val numbers for a strong ensemble. Let me build it and also save a combined metric. I'll create the production approach and test train→val. Let me first look at the official validation performance with a strong blend. Let me write the candidate final pipeline and evaluate on val. Given time, let me define the blend: weighted average of ET(rich), ETnr, HGB(rich), RF(rich), and a light MLP(rich) + SVR(rich). Let me compute train→val for each on rich features and blend. Let me do that now.
Confirmed: all features matter (δ* is not a sufficient statistic; dropping angle/chord or thickness hurts badly). The full-feature ensemble is near-best. Let me get honest numbers on the **official validation split** (the designated proxy, most similar to hidden) for individual learners and blends, using rich features throughout.
bash
cd /app && cat > /tmp/val_eval.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, ExtraTreesRegressor, RandomForestRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
Xtr,ytr=F.Xy(tr); Xva,yva=F.Xy(va); cva=condition_key(va)
defs={
 'ET': lambda: ExtraTreesRegressor(n_estimators=1000,max_features=0.6,n_jobs=-1,random_state=0),
 'HGB': lambda: HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0),
 'RF': lambda: RandomForestRegressor(n_estimators=800,max_features=0.5,min_samples_leaf=2,n_jobs=-1,random_state=0),
 'SVR': lambda: make_pipeline(StandardScaler(),SVR(C=30,gamma='scale',epsilon=0.05)),
 'MLP': lambda: make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=(128,128,64),max_iter=3000,alpha=1e-3,random_state=0)),
}
P={}
for n,mk in defs.items():
    P[n]=mk().fit(Xtr,ytr).predict(Xva)
    m=metrics(yva,P[n],cva)
    print(f'{n:5s} VAL rmse={m["rmse"]:.3f} mae={m["mae"]:.3f} p90={m["p90"]:.2f} p95={m["p95"]:.2f} max={m["maxc"]:.2f}')
for combo in [['ET','HGB'],['ET','HGB','RF'],['ET','HGB','SVR','MLP'],['ET','HGB','RF','SVR','MLP']]:
    pr=np.mean([P[n] for n in combo],axis=0); m=metrics(yva,pr,cva)
    print(f'BLEND {"+".join(combo):20s} rmse={m["rmse"]:.3f} mae={m["mae"]:.3f} p90={m["p90"]:.2f} p95={m["p95"]:.2f} max={m["maxc"]:.2f}')
np.savez('/tmp/valP.npz', y=yva.values, cond=cva.values, **P)
EOF
timeout 250 python3 /tmp/val_eval.py
output
ET    VAL rmse=2.319 mae=1.791 p90=3.33 p95=3.48 max=3.67
HGB   VAL rmse=2.677 mae=1.967 p90=4.08 p95=4.36 max=4.83
RF    VAL rmse=2.780 mae=2.177 p90=3.93 p95=4.06 max=4.15
SVR   VAL rmse=2.699 mae=1.930 p90=4.21 p95=4.41 max=4.43
MLP   VAL rmse=2.475 mae=1.868 p90=3.94 p95=4.13 max=4.15
BLEND ET+HGB               rmse=2.403 mae=1.829 p90=3.73 p95=3.89 max=3.91
BLEND ET+HGB+RF            rmse=2.495 mae=1.915 p90=3.73 p95=3.83 max=3.96
BLEND ET+HGB+SVR+MLP       rmse=2.207 mae=1.670 p90=3.22 p95=3.38 max=3.65
BLEND ET+HGB+RF+SVR+MLP    rmse=2.282 mae=1.735 p90=3.34 p95=3.46 max=3.67
On the official validation (15 conditions): - Best blend ET+HGB+SVR+MLP: rmse 2.207, mae 1.670, p90 3.22, p95 3.38, max 3.65. So on val: rmse 2.21 (✓ <=2.25), p95 3.38 (✓), max 3.65 (✓), mae 1.67 (✗ need 1.55), p90 3.22 (✗ need 2.35). The max and p95 are comfortably under target. Only p90 and mae fail. On 15 conditions, p90 ≈ 90th percentile ≈ the 2nd-highest of 15 (index ~13.6). So p90 = 3.22 means the 2nd worst condition is 3.22. The max (worst) is 3.65. So the top 2 conditions are 3.22-3.65. For p90<=2.35, I need the 2nd-worst condition <=2.35, i.e., at most 1 condition above 2.35 (the max can be up to 5.60). Wait, with 15 conditions, np.percentile(,90) uses linear interpolation: index = 0.9*(15-1) = 12.6, so between the 13th and 14th sorted values (0-indexed 12 and 13). So p90 is between the 2nd and 3rd worst. To get p90<=2.35, I need roughly the 3rd-worst and below <=2.35, allowing ~2 conditions above 2.35. Currently on val, how many conditions are above 2.35? Let me check. The earlier ET val per-condition showed many above 2.35 (8 of 15 were >2.3). So I need to drastically cut that. I keep coming back to: most conditions need to be under 2.35. This is the interpolation-level performance. Let me take yet another step back. The required p90 (2.35) ≈ required rmse (2.25). For p90≈rmse, the per-condition RMSEs must be tightly clustered around the global RMSE (no heavy tail until p95+). This happens when errors are homoscedastic across conditions. Currently my errors have a tail (some conditions much worse). Given the noise floor is ~1.0 and interpolation rmse is 1.5 with p90 2.22, the achievable regime is tight. For grouped/held-out, I'm at rmse 2.2 but p90 3.3 , a heavier tail because some held-out conditions are systematically off. Let me reconsider if there's label leakage potential being hinted: "Raw labels copied from external UCI files are not valid labels for this benchmark and may be rejected as source-label leakage." This strongly implies people might try to match rows to the UCI dataset and copy labels. The benchmark is "calibrated" so those raw labels are wrong AND detected. So the intended solution is honest ML. Good, I'm doing that. Given the difficulty, let me reconsider whether my CV is unnecessarily pessimistic due to my condition grouping being too fine (splitting true conditions into multiple groups, creating small noisy groups with high RMSE variance). If the grader's grouping is coarser, small-group noise inflates my p90 relative to the grader's. Let me check: my grouping gave some conditions with as few as 8 rows. The UCI frequency sweeps typically have ~15-20 points. If my snapping splits a true condition (e.g., angle 12.3 vs 12.6) the grouping differs from truth. Let me verify my groups align with true UCI conditions by checking if each group is a clean frequency sweep (monotonic coverage). Actually, let me reconsider the angle snapping. My ANGLES list might be wrong. The true UCI angles are: 0, 1.5, 3, 4, 5.3, 6.7, 7.3, 8.9, 9.9, 11, 12.3, 12.6, 15.4, 15.6, 17.4, 19.7, 22.2. But the calibrated data might use a different set. My cluster centers earlier were: [-0.0, 1.82, 3.19, 4.04, 5.04, 7.1, 8.64, 9.72, 11.2, 12.48, 15.48, 17.4, 19.69, 22.2] , only 14 clusters (noise merged some). The merged ones (5.04 might be 5.3, 7.1 might be 6.7/7.3 merged, 8.64 = 8.9, 12.48 = 12.3/12.6 merged, 15.48 = 15.4/15.6 merged). So my angle grid over-merges. This means my conditions might COMBINE two true conditions (e.g., 12.3 and 12.6) into one group. That would AVERAGE their errors , could go either way. This grouping uncertainty means my p90 proxy is noisy. The grader's actual p90 could be better or worse. Given all this, my best path: build the strongest, most robust ensemble (lowest rmse, mae, and tightest per-condition distribution), and accept that I've optimized the proxy. The blend ET+HGB+SVR+MLP gives val rmse 2.21, mae 1.67, p90 3.22, max 3.65. But mae 1.67 > 1.55 and p90 3.22 > 2.35 concern m …[truncated]
On validation, the best blend hits rmse 2.21, p95 3.38, max 3.65 (all good) but **mae 1.67 and p90 3.22 miss**. Let me decompose per-condition error into level-bias vs shape components to target the fix.
bash
cd /app && timeout 200 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import numpy as np, pandas as pd
d=np.load('/tmp/valP.npz')
y=d['y']; cond=d['cond']
pred=np.mean([d['ET'],d['HGB'],d['SVR'],d['MLP']],axis=0)
err=pred-y
df=pd.DataFrame({'c':cond,'e':err})
rows=[]
for c,g in df.groupby('c'):
    e=g.e.values; rmse=np.sqrt(np.mean(e**2)); bias=e.mean(); shape=np.sqrt(np.mean((e-bias)**2))
    rows.append((c,len(e),rmse,bias,shape))
r=pd.DataFrame(rows,columns=['c','n','rmse','bias','shape']).sort_values('rmse',ascending=False)
print(r.round(2).to_string(index=False))
print()
print('mean |bias|=%.3f mean shape=%.3f'%(r.bias.abs().mean(),r.shape.mean()))
print('conditions with rmse>2.35: %d of %d'%((r.rmse>2.35).sum(),len(r)))
print('of those, bias-dominated (|bias|>shape):',((r.rmse>2.35)&(r.bias.abs()>r.shape)).sum())
"
output
[stderr]
Traceback (most recent call last):
  File "<string>", line 6, in <module>
  File "/usr/local/lib/python3.12/dist-packages/numpy/lib/npyio.py", line 256, in __getitem__
    return format.read_array(bytes,
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/dist-packages/numpy/lib/format.py", line 795, in read_array
    raise ValueError("Object arrays cannot be loaded when "
ValueError: Object arrays cannot be loaded when allow_pickle=False
bash
cd /app && timeout 200 python3 -c "
import numpy as np, pandas as pd
d=np.load('/tmp/valP.npz',allow_pickle=True)
y=d['y']; cond=d['cond']
pred=np.mean([d['ET'],d['HGB'],d['SVR'],d['MLP']],axis=0)
err=pred-y
df=pd.DataFrame({'c':cond,'e':err})
rows=[]
for c,g in df.groupby('c'):
    e=g.e.values; rmse=np.sqrt(np.mean(e**2)); bias=e.mean(); shape=np.sqrt(np.mean((e-bias)**2))
    rows.append((c,len(e),rmse,bias,shape))
r=pd.DataFrame(rows,columns=['c','n','rmse','bias','shape']).sort_values('rmse',ascending=False)
print(r.round(2).to_string(index=False))
print('mean |bias|=%.3f mean shape=%.3f'%(r.bias.abs().mean(),r.shape.mean()))
print('conditions with rmse>2.35: %d of %d; bias-dominated:'%((r.rmse>2.35).sum(),len(r)),((r.rmse>2.35)&(r.bias.abs()>r.shape)).sum())
"
output
c  n  rmse  bias  shape
17.4_0.0254_39.6 15  3.65 -0.02   3.65
 0.0_0.0254_71.3 10  3.26 -0.63   3.20
12.3_0.1016_55.5 16  3.15 -1.99   2.45
 8.9_0.0508_55.5 12  2.91  0.56   2.85
 6.7_0.1016_55.5  8  2.75 -1.56   2.27
12.3_0.1016_39.6 16  2.44 -1.83   1.62
 4.0_0.2286_31.7 15  1.74 -0.93   1.48
 0.0_0.3048_31.7 18  1.67  1.37   0.95
 0.0_0.1524_39.6 14  1.60  0.87   1.35
 5.3_0.0254_71.3 11  1.56 -1.10   1.10
 5.3_0.0254_39.6 14  1.55  0.25   1.53
 0.0_0.0254_39.6 11  1.36  0.81   1.09
 3.0_0.1016_71.3 12  1.23  0.11   1.23
 0.0_0.0508_55.5 13  0.98  0.23   0.95
 9.9_0.1524_31.7 16  0.90 -0.26   0.86
[stderr]
Traceback (most recent call last):
  File "<string>", line 14, in <module>
AttributeError: 'tuple' object has no attribute 'mean'
The decomposition is very informative. The worst conditions: - 17.4_0.0254_39.6: rmse 3.65, bias 0, shape 3.65 → SHAPE error (spectral shape wrong at high angle). - 0.0_0.0254_71.3: rmse 3.26, shape 3.20 → SHAPE. - 12.3_0.1016_55.5: rmse 3.15, bias -1.99, shape 2.45 → BOTH. - 8.9_0.0508_55.5: rmse 2.91, shape 2.85 → SHAPE. - 6.7_0.1016_55.5: bias -1.56, shape 2.27 → BOTH. - 12.3_0.1016_39.6: bias -1.83 → BIAS-dominated. So it's a MIX. Several are shape-dominated (the spectral curve across frequency is wrong), several have negative bias at high angle/mid-chord (underprediction). Shape errors at high angle (17.4, 0.0254 small chord) and high velocity (71.3): the model gets the frequency dependence wrong. These are conditions where the spectral peak/rolloff differs. The small-chord (0.0254) high-frequency behavior: at small chord, the spectrum extends to higher frequency. The model may not extrapolate the high-frequency rolloff. Bias at 12.3_0.1016 (high angle, medium chord): underprediction , likely separation/stall noise onset that the model underestimates. To fix shape errors, I need the model to capture frequency dependence accurately for these regimes. The smoothing idea failed because the model's shape is biased (not jittery). Hmm, the shape component at 17.4_0.0254_39.6 is 3.65 , that's large. The model's predicted curve vs true curve across frequency differs by 3.65 RMS even after removing the mean. That means the spectral SHAPE is quite wrong for this condition. Let me look at that specific condition: is it at the edge of the frequency range? Small chord 0.0254 + high angle 17.4. In training, do we have 0.0254 at high angles? And 17.4 at other chords? This is extrapolation in the angle×chord×frequency interaction. Very hard. Given the difficulty, let me consider that the hidden test might not contain these specific hard conditions, OR might contain others. My val set is what it is. Let me take a pragmatic stance: I'll build the best possible robust ensemble and also apply a mild shape regularization where it helps. But my earlier poly-smoothing didn't help because shape errors are biased, not jittery. Let me reconsider. Maybe I can improve the spectral shape modeling by giving the model better frequency features. The spectral shape is governed by Strouhal number St = f*delta*/U (peak location). Let me ensure the model has the RIGHT peak-relative frequency. In BPM, the spectrum peaks at a specific St. If I provide log(St) AND the model can learn the universal shape, held-out conditions would share the shape. I already provide log_St_d. But trees treat log_freq and log_St_d as separate; maybe giving ONLY log_St_d (not raw log_freq) for the frequency dependence would force the universal-shape behavior. But earlier removing features hurt. The model benefits from both. Let me try a different tack to reduce shape error: add more Strouhal-like features at different scalings and polynomial terms of log_St so smooth models capture the universal spectral shape, and let trees pick. Actually, I've spent a lot. Let me make a decision on the modeling and also hedge on robustness. The reality: - My val metrics: rmse 2.21 (✓), p95 3.38 (✓), max 3.65 (✓), mae 1.67 (✗), p90 3.22 (✗). - I need to get mae from 1.67 to <=1.55 and p90 from 3.22 to <=2.35. These are substantial gaps on the val proxy. But maybe the hidden set differs. Let me at least maximize and make mae/p90 as low as possible. Let me try to improve via: 1. Better MLP (the smooth model) with the rich features and more capacity + ensembling many seeds → lower variance, better shape generalization. 2. Optimal blend weights. Let me test a larger MLP ensemble on val and see if it helps the shape-dominated conditions. Let me also reconsider: maybe a weighted blend favoring ET (best max/rmse) plus many MLPs (smooth shape). Let me generate several MLP seeds on rich features train→val and see. Let me generate more base predictions on val: MLP x5 seeds (rich), ET(ri …[truncated]
Errors are a mix of spectral-shape and level-bias, concentrated at high-angle/high-velocity held-out regimes. Smooth models (MLP) may generalize shape better. Let me build a multi-seed MLP ensemble plus trees and search blends, targeting mae and p90.
bash
cd /app && cat > /tmp/val_eval2.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.ensemble import HistGradientBoostingRegressor, ExtraTreesRegressor
from sklearn.svm import SVR
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
Xtr,ytr=F.Xy(tr); Xva,yva=F.Xy(va); cva=condition_key(va)
P={}
P['ET']=ExtraTreesRegressor(n_estimators=1000,max_features=0.6,n_jobs=-1,random_state=0).fit(Xtr,ytr).predict(Xva)
P['HGB']=HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0).fit(Xtr,ytr).predict(Xva)
P['SVR']=make_pipeline(StandardScaler(),SVR(C=30,gamma='scale',epsilon=0.05)).fit(Xtr,ytr).predict(Xva)
mlps=[]
for s in range(6):
    arch=[(128,128,64),(200,100),(150,150,75),(256,128),(128,96,64,32),(180,120,60)][s]
    pr=make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=arch,max_iter=4000,alpha=1e-3,random_state=s,early_stopping=False)).fit(Xtr,ytr).predict(Xva)
    mlps.append(pr)
P['MLP']=np.mean(mlps,axis=0)
def show(name,pr):
    m=metrics(yva,pr,cva); print(f'{name:24s} rmse={m["rmse"]:.3f} mae={m["mae"]:.3f} p90={m["p90"]:.2f} p95={m["p95"]:.2f} max={m["maxc"]:.2f}')
show('MLPx6',P['MLP'])
for combo in [['ET','HGB','SVR','MLP'],['ET','MLP'],['ET','HGB','MLP'],['ET','SVR','MLP']]:
    show('+'.join(combo),np.mean([P[n] for n in combo],axis=0))
# weight search (coarse) over ET,HGB,SVR,MLP minimizing composite
best=None
import itertools
names=['ET','HGB','SVR','MLP']
for ws in itertools.product([0,1,2,3],repeat=4):
    if sum(ws)==0: continue
    w=np.array(ws)/sum(ws); pr=sum(w[i]*P[names[i]] for i in range(4))
    m=metrics(yva,pr,cva)
    score=(m['p90']/2.35)+(m['mae']/1.55)+(m['rmse']/2.25)+0.3*(m['maxc']/5.6)
    if best is None or score<best[0]: best=(score,ws,m)
print('BEST weights',best[1],{k:round(v,3) for k,v in best[2].items()})
np.savez('/tmp/valP2.npz', y=yva.values, cond=cva.values, **P)
EOF
timeout 280 python3 /tmp/val_eval2.py
output
MLPx6                    rmse=2.219 mae=1.695 p90=3.28 p95=3.61 max=3.85
ET+HGB+SVR+MLP           rmse=2.224 mae=1.669 p90=3.44 p95=3.55 max=3.61
ET+MLP                   rmse=2.159 mae=1.623 p90=3.11 p95=3.27 max=3.48
ET+HGB+MLP               rmse=2.196 mae=1.664 p90=3.28 p95=3.43 max=3.64
ET+SVR+MLP               rmse=2.236 mae=1.654 p90=3.29 p95=3.39 max=3.62
BEST weights (1, 1, 0, 3) {'rmse': 2.132, 'mae': 1.596, 'p90': 3.014, 'p95': 3.169, 'maxc': 3.528, 'ncond': 15}
Best weighted blend (ET=1, HGB=1, MLP=3): rmse 2.13, mae 1.60, p90 3.01, p95 3.17, max 3.53. Better, but p90 3.01 still > 2.35 and mae 1.60 > 1.55. ET+MLP blend: rmse 2.16, mae 1.62, p90 3.11, max 3.48. The MLP-heavy blend helps. But p90 ~3.0 persists. I'm overfitting weights to 15 conditions if I push too hard. The p90 wall at ~3.0 seems fundamental with this feature/model approach. The shape-dominated conditions (17.4_0.0254_39.6 = 3.65 shape) won't go away with blending. Let me reconsider the problem completely. I've been assuming standard ML. But the huge gap between interpolation (p90 2.22) and extrapolation (p90 3.0-3.4) suggests the held-out conditions need their spectral curve inferred from physics. Let me reconsider the transductive approach seriously, because it's the highest-leverage idea left. The grader stages ALL hidden feature rows and re-runs the script. So at training time I have access to the full set of test feature rows (unlabeled). I can use them. Transductive idea that fixes SHAPE errors: For each test condition (a frequency sweep), the SHAPE of SPL vs frequency is a smooth curve. The model predicts a curve. If the shape is systematically wrong for extrapolated conditions, I can't fix it without labels. BUT , I could use the fact that within a condition the curve must be smooth and physically shaped (single peak, specific rolloff). That's what smoothing tried, didn't help. Alternatively , here's a powerful transductive technique: augment the training set using the test features with PSEUDO-LABELS from the model, then retrain. Self-training. This can help the model adjust decision boundaries near the test distribution. But pseudo-labels from a biased model reinforce bias. Risky. Let me reconsider whether the issue is my condition grouping making val look harder than it is. Let me check: the grader likely uses the TRUE condition (pre-noise). The val set has specific conditions. My snapping merges 12.3/12.6 and 15.4/15.6. If the true val conditions are distinct, my grouping merging them could INFLATE or deflate per-condition RMSE. Actually, the validation set's conditions , let me check how many TRUE conditions are in val. If val has 15 of my merged groups but actually ~15-18 true conditions, it's similar. I think I'm at the point of diminishing returns on the proxy. Let me reconsider the ACTUAL reward mechanics. The target boundary is "solved" at reward>=0.50, and "Reward is bottlenecked by the weakest required metric." Maybe even if I don't hit ALL targets exactly, partial credit exists, but "To pass the solved boundary, all required metrics must meet the hidden targets." So for reward>=0.50 I need all metrics under target. Given my val proxy shows p90~3.0 and mae~1.6, I'm not clearly passing. But the hidden set could be more forgiving (more conditions → smoother percentiles, or different conditions). Let me reconsider: maybe I should trust that the hidden set is LARGER than 15 conditions (the val is just a small local proxy). If the hidden set has, say, 40+ conditions sampled similarly to the overall distribution, then p90 would be like my grouped-CV p90 over 82 conditions (3.35) , still too high. Hmm. Wait, but actually , let me reconsider. Maybe I'm being too pessimistic because my MODEL isn't good enough, not because the task is impossible. The task explicitly says these targets are achievable ("The solved boundary is bottlenecked by..."). The task designers believe a good solution hits p90<=2.35. So there must be a modeling approach that gets most held-out conditions under 2.35. Let me think about what that approach is. The key must be capturing the physics well enough that extrapolation works. Let me reconsider feature engineering for the SPECTRAL SHAPE. In BPM, the TBL-TE spectrum shape is a function A(St/St_peak) where St_peak depends on Reynolds number. The spectral shape function A is a specific curve (in dB) that rises ~St² at low St, peaks, and falls. If I provide the model w …[truncated]
The p90 wall (~3.0) is driven by spectral-shape errors in extrapolated regimes. The BPM model says the TBL-TE spectrum collapses on Strouhal number relative to a peak. Let me examine the actual spectra and test whether a peak-relative frequency feature improves collapse.
bash
cd /app && timeout 120 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import numpy as np, pandas as pd
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
alld['k']=condition_key(alld).values; alld['lf']=np.log10(alld.frequency)
# for each condition find peak freq (argmax SPL) and shape
rows=[]
for k,g in alld.groupby('k'):
    g=g.sort_values('lf')
    i=g.scaled_sound_pressure_level.values.argmax()
    rows.append((k,len(g),g.lf.values[i],g.scaled_sound_pressure_level.max(),g.scaled_sound_pressure_level.min(),
                 g.attack_angle.mean(),g.chord_length.mean(),g.free_stream_velocity.mean(),g.suction_side_displacement_thickness.mean()))
r=pd.DataFrame(rows,columns=['k','n','lf_peak','smax','smin','a','c','u','d'])
# how often is peak at the lowest frequency (monotonic decreasing)?
print('fraction peak at lowest freq bin:', (r.groupby('k').head(1).lf_peak.values==[alld[alld.k==k].lf.min() for k in r.k]).mean().round(2) if False else 'skip')
lfmins=alld.groupby('k').lf.min(); 
r['at_low']= [abs(lp-lfmins[k])<0.05 for k,lp in zip(r.k,r.lf_peak)]
print('frac peak at lowest bin:',r.at_low.mean().round(2))
print('lf_peak range:',r.lf_peak.min().round(2),r.lf_peak.max().round(2))
# regress lf_peak on log features
import numpy as np
X=np.column_stack([np.ones(len(r)),np.log10(r.d),np.log10(r.u),np.log10(r.c),r.a])
b,_,_,_=np.linalg.lstsq(X,r.lf_peak,rcond=None); pr=X@b; resid=r.lf_peak-pr
print('lf_peak regression R2=%.2f resid_std=%.3f'%(1-resid.var()/r.lf_peak.var(),resid.std()))
print('dynamic range (smax-smin) median:',(r.smax-r.smin).median().round(1))
"
output
fraction peak at lowest freq bin: skip
frac peak at lowest bin: 0.0
lf_peak range: 2.4 3.9
lf_peak regression R2=0.89 resid_std=0.120
dynamic range (smax-smin) median: 16.7
Very promising! - The spectral peak is NOT at the lowest frequency bin (frac=0.0), so there's a real peak in range. - lf_peak (log10 of peak frequency) ranges 2.4 to 3.9 and is predictable from log features with R²=0.89, residual std 0.12 (in log10 units). So the peak frequency IS well-predicted by (log_thick, log_vel, log_chord, angle). This means I can construct a "peak-relative" frequency feature: rel_lf = log_freq - lf_peak_predicted. The spectral shape vs rel_lf should collapse across conditions, enabling much better generalization. BUT , the model already has log_freq and all the features, so in principle a flexible model can construct this internally. The question is whether trees do it well. Trees struggle because the peak location is a smooth function and they'd need many splits. By providing rel_lf explicitly, I help the model collapse the shape. Let me build this feature: 1. Fit a linear (or small) model to predict lf_peak from [log_thick, log_vel, log_chord, angle] using the training conditions' peak estimates. Actually, I can't compute lf_peak for test conditions (no labels). But I CAN predict lf_peak from the regression (R²=0.89). So I fit the lf_peak regression on training conditions, then for ANY row compute predicted lf_peak from its features, and rel_lf = log_freq - lf_peak_pred. But wait, this requires condition-level peak estimation from training labels to fit the regression , that's fine, it's training. Then rel_lf is computable for any row from features alone. Actually even simpler and more robust: I don't need the peak per se. I can just add rel_lf as an engineered feature = log_freq - (linear combo predicting peak). But the linear combo is learned from data. Let me just include it. Actually, the cleanest: add a feature that is log_freq minus a physics estimate of peak location. Let me use the fitted regression coefficients (from training) to compute lf_peak_pred for all rows, then rel_lf = lf - lf_peak_pred. Add this and maybe rel_lf², rel_lf³ to help capture the universal shape A(rel_lf). Let me also add the St-based version. But rel_lf based on the empirical peak regression is likely best. Let me test this: build features including rel_lf (and powers), and evaluate grouped CV + val. This could be the breakthrough. Importantly, to avoid leakage in CV, the lf_peak regression should be fit only on training folds. But since it's a smooth 5-parameter regression, fitting on all data vs folds makes negligible difference. For correctness in the final pipeline, I'll fit it on the training data available at fit time. For CV evaluation, I'll fit within-fold to be honest. Let me implement as a transformer that fits the peak regression in .fit(). Let me create this enhanced feature pipeline and test on val (train→val) and grouped CV. Let me write a custom estimator that: - In fit(X, y): estimates per-condition peak (needs condition grouping + y), fits lf_peak ~ features regression, stores coef. - In transform: computes rel_lf and powers, appends to features. But condition grouping in fit needs the condition key. I can compute it from X (snapping). Let me pass the raw df. Actually, to keep it simple and avoid leakage concerns, let me fit the peak regression using condition-level peaks derived from the training data. Let me implement carefully. Let me write the enhanced approach and test.
Excellent , the spectral **peak frequency is predictable from features (R²=0.89)**. Adding a "peak-relative frequency" feature should let the model collapse the spectral shape and generalize to unseen conditions. Let me implement this as a leakage-safe transformer and test it.
bash
cd /app && cat > /tmp/features3.py << 'EOF'
import numpy as np, pandas as pd
import sys; sys.path.insert(0,'/tmp')
from cv_harness import condition_key

def base_feats(df):
    f=df['frequency'].astype(float).values; a=df['attack_angle'].astype(float).values
    c=df['chord_length'].astype(float).values; u=df['free_stream_velocity'].astype(float).values
    d=df['suction_side_displacement_thickness'].astype(float).values
    lf=np.log10(f); ld=np.log10(d); lc=np.log10(c); lu=np.log10(u); nu=1.5e-5
    o={}
    o['log_freq']=lf; o['attack_angle']=a; o['log_chord']=lc; o['log_vel']=lu; o['log_thick']=ld
    o['log_St_d']=np.log10(f*d/u); o['log_St_c']=np.log10(f*c/u)
    o['log_Re_c']=np.log10(c*u/nu); o['log_Re_d']=np.log10(d*u/nu)
    o['mach']=u/340.0; o['d_over_c']=d/c; o['log_d_over_c']=np.log10(d/c)
    o['lf_angle']=lf*a; o['lf_ld']=lf*ld; o['lf_lc']=lf*lc; o['lf_lu']=lf*lu
    o['a_ld']=a*ld; o['a_lc']=a*lc; o['a_lu']=a*lu
    o['lf2']=lf*lf; o['angle2']=a*a; o['ld2']=ld*ld
    o['sin_a']=np.sin(np.radians(a))
    return pd.DataFrame(o,index=df.index), dict(lf=lf,ld=ld,lc=lc,lu=lu,a=a)

from sklearn.base import BaseEstimator, TransformerMixin
class PeakRel(BaseEstimator, TransformerMixin):
    """Adds peak-relative log-frequency features. Fits a peak-location regression from training labels."""
    def fit(self, df, y):
        df=df.reset_index(drop=True); y=np.asarray(y)
        k=condition_key(df).values
        rows=[]; 
        import pandas as pd
        g=pd.DataFrame({'k':k,'lf':np.log10(df['frequency'].astype(float).values),'y':y,
                        'ld':np.log10(df['suction_side_displacement_thickness'].astype(float).values),
                        'lu':np.log10(df['free_stream_velocity'].astype(float).values),
                        'lc':np.log10(df['chord_length'].astype(float).values),
                        'a':df['attack_angle'].astype(float).values})
        feats=[]; targ=[]
        for key,gg in g.groupby('k'):
            if len(gg)<4: continue
            # smooth peak: fit quadratic in lf, take vertex within range
            co=np.polyfit(gg.lf,gg.y,2)
            if co[0]<0:
                lfp=-co[1]/(2*co[0]); lfp=min(max(lfp,gg.lf.min()),gg.lf.max())
            else:
                lfp=gg.lf.values[gg.y.values.argmax()]
            feats.append([1,gg.ld.mean(),gg.lu.mean(),gg.lc.mean(),gg.a.mean(),gg.a.mean()**2]); targ.append(lfp)
        A=np.array(feats); b=np.array(targ)
        self.coef_,_,_,_=np.linalg.lstsq(A,b,rcond=None)
        return self
    def _predict_peak(self, parts):
        A=np.column_stack([np.ones_like(parts['lf']),parts['ld'],parts['lu'],parts['lc'],parts['a'],parts['a']**2])
        # use row-level feature means? peak depends on condition-level; row features give same since condition-constant-ish
        return A@self.coef_
    def transform(self, df):
        base,parts=base_feats(df)
        lfp=self._predict_peak(parts)
        rel=parts['lf']-lfp
        base['rel_lf']=rel; base['rel_lf2']=rel*rel; base['rel_lf3']=rel**3
        base['rel_pos']=np.maximum(rel,0); base['rel_neg']=np.minimum(rel,0)
        return base.values
EOF
echo "written"
timeout 200 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
from features3 import PeakRel
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
from sklearn.pipeline import make_pipeline
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
ytr=tr['scaled_sound_pressure_level']; yva=va['scaled_sound_pressure_level']; cva=condition_key(va)
for name,mk in [('ET',lambda:ExtraTreesRegressor(n_estimators=1000,max_features=0.6,n_jobs=-1,random_state=0)),
                ('HGB',lambda:HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0))]:
    pipe=make_pipeline(PeakRel(),mk()); pipe.fit(t
…[truncated]
output
written
ET+PeakRel VAL rmse=2.236 mae=1.658 p90=3.41 p95=3.75 max=4.06
HGB+PeakRel VAL rmse=2.389 mae=1.815 p90=3.55 p95=3.92 max=4.38
The PeakRel feature didn't help much (ET: rmse 2.24 vs 2.32 before , slight rmse improvement but p90 3.41 worse, max 4.06 worse). The trees already capture this via existing features, and adding redundant features adds noise. The peak-relative idea isn't the silver bullet for trees. The shape errors persist. Let me step back and think about the token budget (~119k) and make a strategic decision. I've established: - Best blend (ET+HGB+MLP weighted, MLP-heavy): val rmse ~2.13, mae ~1.60, p90 ~3.0, p95 ~3.2, max ~3.5. - rmse, p95, max comfortably pass. mae close (1.60 vs 1.55). p90 is the stubborn one (3.0 vs 2.35). The p90 gap is large and I've tried many things. Let me reconsider whether my VALIDATION proxy's p90 is representative of the hidden set. Critical realization: On my val set of 15 conditions, p90 is computed as np.percentile(15 values, 90) which is essentially the 2nd-worst condition. This is a HIGH-VARIANCE estimate. One bad condition dominates. The hidden set might have a different number of conditions. Also, my per-condition grouping MERGES close angles (12.3+12.6, 15.4+15.6). If the grader treats them separately, a merged group's RMSE differs. Given irreducible uncertainty about the grader's exact grouping and hidden conditions, my best strategy is to MINIMIZE the tail of per-condition errors as robustly as possible, which means: 1. Lowest global RMSE and MAE (helps all metrics). 2. Tightest per-condition distribution (reduce worst conditions). The MLP-heavy blend does well. Let me also consider that maybe averaging MORE diverse models reduces the worst-condition errors. Actually, let me reconsider the whole thing with fresh eyes on ROBUSTNESS. The metric that's most at risk is p90. But notice the targets: p90<=2.35, p95<=4.75, max<=5.60. On my val, I get p90 3.0, p95 3.2, max 3.5. So my p95 and max are WAY under their targets (3.2<<4.75, 3.5<<5.60) but p90 is over its target (3.0>2.35). This is a strange profile: my per-condition errors are tightly clustered (p90≈p95≈max≈3.0-3.5, no heavy tail). The targets EXPECT a heavy tail (p90 2.35 but max up to 5.60). So the target profile suggests: MOST conditions very good (<2.35) with a FEW bad ones (up to 5.60). My model: uniformly mediocre (all ~2-3.5). This means I should aim to make MOST conditions excellent, even at the cost of a few bad ones. The "uniformly mediocre" profile fails p90 but the "mostly excellent + few bad" profile passes p90 (and easily passes p95/max since they allow 4.75/5.60). How to get "mostly excellent"? This points toward INTERPOLATION-quality predictions for most conditions. Which points back to: the model must nail most held-out conditions. Hmm. But if the model can't extrapolate, it's mediocre everywhere, not excellent-mostly. Wait , maybe the issue is that my val set happens to contain several hard conditions. Let me reconsider: is my model actually "uniformly mediocre" or does it have some excellent and some bad? From the decomposition: val conditions ranged from rmse 0.90 (excellent) to 3.65 (bad). So it's NOT uniform , I have 6 conditions <1.7 and several >2.4. So the profile is: ~half good, ~half mediocre-bad. To pass p90 on 15 conditions, I need ~13-14 of 15 under 2.35. Currently ~7-8 are under. I need to roughly double the "good" conditions. I think the honest conclusion is: this requires a genuinely better model than I've built. Let me make one more serious attempt at a fundamentally better approach, then finalize with the best I have. Best remaining idea: Let me reconsider the MLP as the primary model but make it much better , a carefully regularized deep MLP trained on the full rich+physics features with target normalization, trained long, ensembled over many seeds AND folds (bagging). MLPs can learn the smooth physical function and may extrapolate the shape better than trees. My MLPx6 got val rmse 2.22, mae 1.70, p90 3.28 , similar to trees. Not obviously better. Alternatively , maybe I should embrace the stru …[truncated]
The PeakRel feature doesn't help trees (redundant). The key insight from the target profile: p95≤4.75 and max≤5.60 are **generous** while p90≤2.35 is **tight** , the intended model gets *most* conditions excellent with a few bad, whereas mine is uniformly mediocre. Let me run a stable grouped-CV comparison of regularization levels and the MLP-heavy blend to find what tightens p90.
bash
cd /app && cat > /tmp/cv_final.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=F.Xy(alld); cond=condition_key(alld); groups=cond.values
gkf=GroupKFold(5); splits=list(gkf.split(Xall,yall,groups))
def oof(mk,Xd):
    p=np.zeros(len(yall))
    for tri,tei in splits: p[tei]=mk().fit(Xd.iloc[tri],yall.iloc[tri]).predict(Xd.iloc[tei])
    return p
def rep(name,p):
    m=metrics(yall,p,cond); cr=pd.DataFrame({'c':groups,'e':p-yall.values}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'{name:26s} rmse={m["rmse"]:.3f} mae={m["mae"]:.3f} p90={m["p90"]:.2f} p95={m["p95"]:.2f} max={m["maxc"]:.2f} frac<=2.35={(cr<=2.35).mean():.2f}',flush=True)
    return p
et=oof(lambda:ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=0),Xall); rep('ET',et)
etr=oof(lambda:ExtraTreesRegressor(n_estimators=800,max_features=0.6,min_samples_leaf=3,n_jobs=-1,random_state=0),Xall); rep('ET msl3',etr)
hgb=oof(lambda:HistGradientBoostingRegressor(max_iter=800,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0),Xall); rep('HGB',hgb)
mlp=np.mean([oof(lambda s=s:make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=[(128,128,64),(200,100),(150,150,75)][s],max_iter=4000,alpha=1e-3,random_state=s)),Xall) for s in range(3)],axis=0); rep('MLPx3',mlp)
rep('ET+HGB+MLP',(et+hgb+mlp)/3)
rep('1ET+1HGB+3MLP',(et+hgb+3*mlp)/5)
rep('2ET+1HGB+2MLP',(2*et+hgb+2*mlp)/5)
rep('ETr+HGB+MLP',(etr+hgb+mlp)/3)
np.savez('/tmp/oof_final.npz',y=yall.values,cond=groups,et=et,etr=etr,hgb=hgb,mlp=mlp)
print('DONE')
EOF
nohup python3 /tmp/cv_final.py > /tmp/cvf_log.txt 2>&1 &
echo "pid $!"
output
pid 1367
bash
sleep 120 && cat /tmp/cvf_log.txt
output
ET                         rmse=2.369 mae=1.745 p90=3.39 p95=4.02 max=5.44 frac<=2.35=0.68
ET msl3                    rmse=2.462 mae=1.818 p90=3.55 p95=4.17 max=5.46 frac<=2.35=0.66
HGB                        rmse=2.422 mae=1.774 p90=3.67 p95=4.05 max=5.33 frac<=2.35=0.67
MLPx3                      rmse=2.570 mae=1.895 p90=4.02 p95=4.36 max=5.22 frac<=2.35=0.60
ET+HGB+MLP                 rmse=2.201 mae=1.611 p90=3.23 p95=3.45 max=4.57 frac<=2.35=0.70
1ET+1HGB+3MLP              rmse=2.267 mae=1.669 p90=3.35 p95=3.64 max=4.64 frac<=2.35=0.67
2ET+1HGB+2MLP              rmse=2.216 mae=1.625 p90=3.19 p95=3.38 max=4.70 frac<=2.35=0.70
ETr+HGB+MLP                rmse=2.228 mae=1.634 p90=3.23 p95=3.49 max=4.57 frac<=2.35=0.68
DONE
On the stable 82-condition grouped CV: - Best blend (2ET+1HGB+2MLP): rmse 2.216, mae 1.625, p90 3.19, p95 3.38, max 4.70, frac<=2.35=0.70. - ET+HGB+MLP: rmse 2.201, mae 1.611, p90 3.23, max 4.57. So on the full CV, p90 ~3.2, frac<=2.35 ~0.70. Still far from 0.90. The regularized ET (msl3) was worse. So more regularization doesn't help here. I've now done extensive modeling. The honest conclusion: with standard ML on these features, grouped-CV p90 plateaus around 3.2, frac<=2.35 around 0.70. The target p90<=2.35 requires frac<=2.35 around 0.90. There's a persistent ~0.85 dB gap on p90. This strongly suggests I'm missing something structural, OR the targets rely on the hidden set being constructed differently/more favorably than my CV. Let me reconsider the task statement once more: "a calibrated benchmark derived from the public UCI Airfoil Self-Noise measurements." and the specific target values. The phrase "calibrated" + the warning about "source-label leakage" suggests the labels were transformed from UCI. Let me reconsider: maybe the hidden test set features are the CLEAN UCI grid values (not noisy), while the train/val features are noisy. If the hidden features are clean, then the conditions group perfectly and the model (trained on noisy features) predicts on clean features. That wouldn't drastically change difficulty though. Alternatively , maybe I should reconsider the magnitude of feature noise. If I could "denoise" the features (snap to grid), predictions might be cleaner. Let me test: snap test/val features to the canonical grid before prediction, and train on snapped features too. This removes feature noise, potentially improving consistency. Actually, snapping features to grid could help because: 1. It removes feature noise (which adds prediction variance). 2. It makes held-out conditions align with the grid structure. But the labels were generated from noisy features presumably. Hmm. Let me test snapping. Actually, let me reconsider the displacement thickness. delta* is NOT on a simple grid , it's continuous (derived). Snapping angle/chord/velocity but keeping delta* might help. Let me test: train and predict with angle/chord/velocity snapped to canonical grid (removing their noise), keeping frequency and delta* as-is. This denoises 3 of 5 features. Let me test this quickly on grouped CV and val. Actually wait , a cleaner idea for reducing per-condition error: since within a condition, angle/chord/velocity should be CONSTANT (they're condition-defining), but noise makes them vary row-to-row. If I snap them to the condition's representative value (e.g., median within condition), then all rows in a condition share identical angle/chord/velocity , and the model's prediction variation across the condition comes only from frequency/delta*. This could reduce spurious per-condition variance. For test conditions, I'd snap using the grid. Let me test snapping angle/chord/velocity to canonical grid for BOTH train and eval. Let me also reconsider delta*: within a condition, delta* should be constant too (it's determined by angle/chord/velocity). But it has noise. Snapping delta* to its condition-median would require grouping. For test, I can group by snapped condition and take median delta*. That denoises delta* per condition. This "condition denoising" could meaningfully reduce per-condition error variance. Let me test it. Plan for test-time denoising: 1. Snap angle, chord, velocity to canonical grid → defines condition. 2. Within each condition group (in the eval set), replace delta* and frequency? No, frequency varies within condition (it's the sweep). Keep frequency. Replace delta* with the group's... but delta* might legitimately be constant per condition. Let me check: within a training condition, does delta* vary only by noise? Let me check delta* coefficient of variation within conditions. Let me test both snapping features and the condition-denoising.
Grouped-CV p90 plateaus at ~3.2. Let me test a different lever: the condition-defining features (angle/chord/velocity, and δ*) should be *constant* within a condition, but noise makes them vary. **Denoising** them (snapping to grid / condition-median) could cut spurious per-condition variance. Let me first check how much these vary within conditions.
bash
cd /app && timeout 120 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import numpy as np, pandas as pd
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
alld['k']=condition_key(alld).values
for col in ['attack_angle','chord_length','free_stream_velocity','suction_side_displacement_thickness']:
    cv=alld.groupby('k')[col].apply(lambda s: s.std()/ (abs(s.mean())+1e-9))
    print(f'{col:36s} within-cond CoV median={cv.median():.4f} max={cv.max():.4f}')
# is delta* constant within condition (ignoring noise)?
d=alld.groupby('k')['suction_side_displacement_thickness'].agg(['mean','std','min','max'])
print('delta* within-cond relative spread (max-min)/mean median:', ((d['max']-d['min'])/d['mean']).median().round(3))
"
output
attack_angle                         within-cond CoV median=0.0038 max=44.3050
chord_length                         within-cond CoV median=0.0009 max=0.0010
free_stream_velocity                 within-cond CoV median=0.0010 max=0.0012
suction_side_displacement_thickness  within-cond CoV median=0.0018 max=0.0021
delta* within-cond relative spread (max-min)/mean median: 0.005
The within-condition coefficient of variation is TINY: - attack_angle CoV 0.0038 (but max 44 for the 0-degree condition where mean≈0, so noise is tiny absolute ~0.04 deg) - chord 0.0009, velocity 0.0010, delta* 0.0018. So angle/chord/velocity/delta* are essentially CONSTANT within a condition (noise ~0.1-0.5%). This confirms they're condition-defining and the noise is tiny. So denoising them won't change much (the noise is already negligible). The feature noise isn't the problem. So the per-condition errors are genuine model extrapolation errors, not feature noise. Denoising won't help. OK. I've thoroughly explored this. Let me accept the modeling reality and think about the meta-question: is the target achievable, and what's my best shot? Let me reconsider the gap between my grouped CV (p90 3.2) and the target (2.35) once more. The target was presumably set by the benchmark creators based on a reference solution. Maybe their reference solution used a model class I haven't tried, or maybe their hidden set is easier than my CV. Let me reconsider: my grouped CV uses 5 folds over 82 conditions, so each fold holds out ~16 conditions, trains on ~66. The actual task trains on train.csv (67 conditions) + I can add validation (15) = 82 conditions, and predicts the HIDDEN set. If the hidden set is, say, 15-40 conditions NOT in my 82, then my model trains on ALL 82 conditions (more data than any CV fold) → better than CV estimate. So my final model, trained on all 82 conditions, will be somewhat better than the CV numbers (which train on only ~66). That's a favorable factor. How much better? Going from 66→82 training conditions (+24% data) might reduce error by ~5-10%. Not enough to close the gap alone. Let me reconsider: maybe I should include MORE data diversity. I only have train+val = 82 conditions. Can't get more (no external data allowed). Let me make my peace and also try ONE more potentially-high-impact idea: a proper STACKING ensemble where a meta-learner combines base models, possibly capturing where each is reliable. And combine with the peak-relative features for the MLP. But stacking on 82 conditions risks overfit. Actually, let me reconsider the possibility that the benchmark's per-condition grouping is COARSER than mine, which would LOWER the p90. For instance, if the grader groups by (chord, velocity) only, or by coarser angle bins, there'd be fewer, larger groups, and per-condition RMSE would average over more rows → the distribution tightens toward the global RMSE. My global RMSE is ~2.2, so p90 of coarser groups would be closer to 2.2-2.5 → potentially passing! Conversely if finer, p90 worsens. The task explicitly says condition = (attack_angle, chord_length, free_stream_velocity). That's my grouping. So probably similar granularity. Alright. Let me also reconsider: the metric is per-condition RMSE. For a condition with few rows, RMSE is noisier. My smallest groups have ~8 rows. If the hidden set conditions have MORE rows each (full frequency sweeps ~15-20), per-condition RMSE is more stable (closer to the true per-condition bias+noise), which could be higher or lower. I'm going in circles on speculation. Let me take decisive action: 1. Build the best robust model I can (weighted blend ET+HGB+MLP, tuned). 2. Train on ALL labeled data (train+val). 3. Apply the frequency-smoothing ONLY if it helps (it didn't, so skip). 4. Write predictions. And crucially, make the pipeline robust and correct for the grader (reads test_features.csv, writes predictions.csv with right columns, handles any number of rows). But before finalizing, let me make a genuine last attempt at substantially improving generalization via an approach I haven't tried: data augmentation by leveraging the physics-based spectral collapse to generate synthetic training signal, OR a carefully designed neural net with the peak-relative feature that forces shape collapse. Actually, let me try the MLP WITH peak-relative features (features3) , smo …[truncated]
Within-condition feature noise is negligible (~0.1–0.5%), so denoising won't help , the per-condition errors are genuine extrapolation. Smooth models should benefit most from the physics collapse feature. Let me test the MLP with peak-relative features.
bash
cd /app && timeout 250 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
from features3 import PeakRel
import features2 as F
import pandas as pd, numpy as np
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
tr=pd.read_csv('data/train.csv'); va=pd.read_csv('data/validation.csv')
ytr=tr['scaled_sound_pressure_level']; yva=va['scaled_sound_pressure_level']; cva=condition_key(va)
# MLP with PeakRel
def mlp_pr(s,arch):
    return make_pipeline(PeakRel(),StandardScaler(),MLPRegressor(hidden_layer_sizes=arch,max_iter=4000,alpha=1e-3,random_state=s))
archs=[(128,128,64),(200,100),(150,150,75)]
prs=[]
for s in range(3):
    p=mlp_pr(s,archs[s]); p.fit(tr,ytr); prs.append(p.predict(va))
mlp_pr_pred=np.mean(prs,axis=0)
m=metrics(yva,mlp_pr_pred,cva); print('MLPx3+PeakRel VAL',{k:round(v,3) for k,v in m.items()})
# compare plain MLP rich
Xtr,_=F.Xy(tr); Xva,_=F.Xy(va)
prs2=[make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=archs[s],max_iter=4000,alpha=1e-3,random_state=s)).fit(Xtr,ytr).predict(Xva) for s in range(3)]
mlp_plain=np.mean(prs2,axis=0)
print('MLPx3 plain VAL',{k:round(v,3) for k,v in metrics(yva,mlp_plain,cva).items()})
" 2>&1 | grep -v Warning
output
MLPx3+PeakRel VAL {'rmse': 2.454, 'mae': 1.801, 'p90': 3.572, 'p95': 3.64, 'maxc': 3.789, 'ncond': 15}
MLPx3 plain VAL {'rmse': 2.328, 'mae': 1.786, 'p90': 3.335, 'p95': 3.757, 'maxc': 4.258, 'ncond': 15}
PeakRel doesn't help the MLP either (rmse 2.45 vs 2.33 plain). My peak estimation or the feature adds noise. Let me abandon PeakRel. OK. I've spent considerable effort. The models plateau at grouped-CV p90 ~3.2 and val p90 ~3.0. Let me now seriously reconsider whether the hidden targets might be more achievable than my proxy suggests, and just build the most robust possible solution. Actually, let me reconsider one important thing: the reward function. It says "Reward uses the ML4Eng Reward V3 convention: reward >= 0.50 means solved. Reward is bottlenecked by the weakest required metric." This implies a CONTINUOUS reward per metric, and the overall reward is the minimum across metrics (bottleneck). Being under target gives reward>=0.50 for that metric. So even if I don't hit all targets, I get SOME reward (the min across metrics). My goal is to maximize the minimum , which means I should balance all metrics, and especially improve the WORST one relative to its target. My metrics relative to targets (using grouped CV, trained on subset , final will be a bit better): - rmse 2.20 / 2.25 = 0.98 (just under ✓) - mae 1.61 / 1.55 = 1.04 (just over) - p90 3.2 / 2.35 = 1.36 (well over , WORST) - p95 3.4 / 4.75 = 0.72 (well under ✓) - max 4.6 / 5.60 = 0.82 (under ✓) So p90 is the bottleneck at 1.36x target. To maximize reward, I must focus on p90. Even getting p90 from 3.2 to 2.8 improves the bottleneck reward. So: how to reduce p90 specifically? p90 = ~8th worst of 82 conditions (or 2nd worst of 15 in val). I need to reduce the number of moderately-bad conditions. The frac<=2.35 is 0.70 in CV. I want to maximize the 90th percentile being low = push the 73rd-worst... no, p90 is the value at the 90th percentile = the condition such that 90% are below it. To lower p90, I lower the error of the conditions ranked around 74-82 (the worst ~10%)... no. p90 is the 90th percentile = roughly the 8th-worst (since 10% of 82 = 8.2). Lowering p90 means lowering the 8th-worst condition's RMSE. That requires improving conditions ranked ~74th-75th. Equivalently, get more conditions under any given threshold. To get p90<=2.35, need 90% under 2.35. Improving the bulk requires better average extrapolation. Blending + good features is the main tool. I'm near the limit. Let me try a couple more diverse base learners to add to the blend that might help the tail: - A KNN in a carefully scaled physical space (for local interpolation among conditions). - Bagged SVR. Actually SVR/KNN had high max. Let me instead try to directly reduce per-condition error via a TRANSDUCTIVE self-training / manifold approach. Or , reconsider the target transform. Hmm, let me reconsider whether predicting in a transformed target space helps. The SPL target is already in dB (log scale). Let me try a completely different and powerful approach for tabular extrapolation: a large ExtraTrees/RandomForest but with FEWER max_features and MORE trees plus a LOCAL linear correction... no. Let me reconsider , maybe I should ACCEPT the blend and focus on making it as good as possible, then ensure robustness. The realistic best is p90~3.0 on val, ~3.2 on CV. Wait, let me reconsider the final training advantage. When I train on ALL 82 conditions and predict a SEPARATE hidden set, the model has seen more conditions than in CV folds. Let me actually estimate this: Leave-one-group-out would train on 81 conditions. That's the closest to the real scenario (train on all available, predict unseen). LOGO CV p90 might be notably lower than 5-fold (which trains on only 66). Let me estimate via a larger number of folds (e.g., 10-fold grouped → trains on ~74 conditions) to see the trend. If p90 drops meaningfully with more training conditions, the real hidden performance is better than my 5-fold estimate. Let me test 5-fold vs 10-fold grouped CV p90 for the blend. Quick check of the trend. Let me use the saved oof_final... no, that's 5-fold. Let me run a 10-fold CV for the main blend c …[truncated]
PeakRel doesn't help. The bottleneck is clearly **p90**. Importantly, the real scenario trains on *all* 82 conditions, while 5-fold CV trains on only ~66. Let me check how metrics improve with more training conditions (5/10/15-fold) to estimate the real-scenario benefit.
bash
cd /app && timeout 280 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import features2 as F
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('data/train.csv'),pd.read_csv('data/validation.csv')],ignore_index=True)
Xall,yall=F.Xy(alld); cond=condition_key(alld); groups=cond.values
for nf in [5,10,20]:
    gkf=GroupKFold(nf); 
    et=np.zeros(len(yall)); hg=np.zeros(len(yall))
    for tri,tei in gkf.split(Xall,yall,groups):
        et[tei]=ExtraTreesRegressor(n_estimators=600,max_features=0.6,n_jobs=-1,random_state=0).fit(Xall.iloc[tri],yall.iloc[tri]).predict(Xall.iloc[tei])
        hg[tei]=HistGradientBoostingRegressor(max_iter=600,learning_rate=0.04,max_leaf_nodes=31,l2_regularization=1.0,min_samples_leaf=15,random_state=0).fit(Xall.iloc[tri],yall.iloc[tri]).predict(Xall.iloc[tei])
    bl=(et+hg)/2
    m=metrics(yall,bl,cond); cr=pd.DataFrame({'c':groups,'e':bl-yall.values}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'{nf}-fold (train~{int(82*(nf-1)/nf)} conds) ET+HGB: rmse={m[\"rmse\"]:.3f} mae={m[\"mae\"]:.3f} p90={m[\"p90\"]:.2f} p95={m[\"p95\"]:.2f} max={m[\"maxc\"]:.2f} frac<=2.35={(cr<=2.35).mean():.2f}')
"
output
5-fold (train~65 conds) ET+HGB: rmse=2.288 mae=1.667 p90=3.30 p95=3.97 max=4.99 frac<=2.35=0.70
10-fold (train~73 conds) ET+HGB: rmse=2.210 mae=1.612 p90=3.37 p95=3.81 max=4.92 frac<=2.35=0.71
20-fold (train~77 conds) ET+HGB: rmse=2.141 mae=1.575 p90=2.92 p95=3.62 max=4.74 frac<=2.35=0.77
There IS a meaningful trend with more training conditions: - 5-fold (train ~65): rmse 2.29, mae 1.67, p90 3.30, frac 0.70 - 10-fold (train ~73): rmse 2.21, mae 1.61, p90 3.37, frac 0.71 - 20-fold (train ~77): rmse 2.14, mae 1.58, p90 2.92, frac 0.77 So as training conditions increase toward the full 82 (real scenario trains on ALL 82), metrics improve: rmse→2.14, mae→1.58, p90→2.92, frac→0.77. Leave-one-group-out (train on 81) would be even better. The trend suggests the real hidden performance (train on 82, predict unseen) is better than my 5-fold estimate , maybe p90 ~2.7-2.9, rmse ~2.1, mae ~1.55. Still p90 likely >2.35 but closer. This is encouraging: the real deployment trains on all 82 conditions, so my pessimistic 5-fold p90 (3.2) overestimates the true error. The 20-fold (train 77) gives p90 2.92. Extrapolating to train-82, maybe p90 ~2.7. So the gap to 2.35 is smaller than feared, but still present. Every bit of model improvement helps the bottleneck. Given this, let me now: 1. Add MLP to the blend (it helped before) and use the strongest configuration. 2. Train on all data. 3. Maximize via a good weighted blend. Let me estimate the final blend (ET+HGB+MLP) with 20-fold CV to get the most realistic estimate, then lock in the approach. Actually MLP is slow for 20-fold. Let me just confirm ET+HGB+MLP at 10-fold and trust the trend. Actually, let me be efficient and move toward finalizing. The plan: - Final model: weighted blend of ET (2x seeds), HGB (2 configs), MLP (3 seeds), all on rich features (features2), trained on all labeled data. - This gave the best balance. But let me reconsider MLP's contribution at higher fold counts. Let me do a 10-fold CV of the full blend ET+HGB+MLPx3 to confirm it beats ET+HGB, then finalize. Let me run it in background. Actually, let me reconsider whether to include validation data in training. Yes , more conditions = better (the trend shows this clearly). The starter already concatenates train+val. I'll keep that. Let me reconsider one more potential improvement for p90: since p90 is the bottleneck and the worst conditions are high-angle/high-velocity, maybe I can improve those specifically. But without more data, hard. Let me also reconsider adding a KNN-in-physical-space model to the blend for diversity , it might help some conditions. But earlier KNN was weak. Skip. Let me do a final CV check of the full blend at 10-fold (realistic-ish), including MLP, then write the production script. Let me run in background while I draft the script. Let me first draft the production script, then validate it end-to-end (it will also serve as the final CV check via its own logic). Actually, let me just run a 10-fold blend check quickly. Let me write the final script now, making it robust, then test it end-to-end. I'll incorporate ET+HGB+MLP blend with weights that performed well (2ET+1HGB+2MLP gave good p90 on 5-fold: p90 3.19; ET+HGB+MLP equal gave 3.23). Let me use a reasonable weighting. Let me determine good weights more carefully using the saved oof_final.npz (5-fold OOF for et, etr, hgb, mlp). Let me search weights minimizing p90 (with constraints rmse/mae reasonable) , but avoid overfitting by keeping weights simple. Let me check a few. Let me load oof_final and search integer weights over (et, hgb, mlp).
There's a clear, encouraging trend: more training conditions sharply improves p90 (20-fold: p90=2.92, frac≤2.35=0.77). Since the real run trains on **all 82 conditions**, true performance should exceed my 5-fold estimates. Let me optimize blend weights on the saved OOF, then lock in the design.
bash
cd /app && timeout 100 python3 -c "
import numpy as np, pandas as pd, itertools, sys; sys.path.insert(0,'/tmp')
from cv_harness import metrics
d=np.load('/tmp/oof_final.npz',allow_pickle=True)
y=d['y']; cond=d['cond']; et=d['et']; hgb=d['hgb']; mlp=d['mlp']
def sc(p):
    m=metrics(y,p,cond); return m
best=[]
for we,wh,wm in itertools.product(range(0,5),repeat=3):
    if we+wh+wm==0: continue
    p=(we*et+wh*hgb+wm*mlp)/(we+wh+wm); m=sc(p)
    best.append((m['p90'],m['rmse'],m['mae'],m['p95'],m['maxc'],(we,wh,wm)))
best.sort()
print('Top by p90 (5-fold OOF):')
for b in best[:6]:
    print(f'  w={b[5]} p90={b[0]:.3f} rmse={b[1]:.3f} mae={b[2]:.3f} p95={b[3]:.3f} max={b[4]:.3f}')
# balanced score
bal=sorted(best,key=lambda b:max(b[1]/2.25,b[2]/1.55,b[0]/2.35,b[3]/4.75,b[4]/5.6))
print('Top by bottleneck ratio:')
for b in bal[:6]:
    print(f'  w={b[5]} p90={b[0]:.3f} rmse={b[1]:.3f} mae={b[2]:.3f} p95={b[3]:.3f} max={b[4]:.3f} bneck={max(b[1]/2.25,b[2]/1.55,b[0]/2.35):.3f}')
"
output
Top by p90 (5-fold OOF):
  w=(2, 0, 1) p90=3.123 rmse=2.262 mae=1.667 p95=3.427 max=4.981
  w=(4, 0, 2) p90=3.123 rmse=2.262 mae=1.667 p95=3.427 max=4.981
  w=(2, 2, 1) p90=3.135 rmse=2.213 mae=1.617 p95=3.584 max=4.564
  w=(4, 4, 2) p90=3.135 rmse=2.213 mae=1.617 p95=3.584 max=4.564
  w=(4, 1, 2) p90=3.143 rmse=2.227 mae=1.634 p95=3.364 max=4.817
  w=(4, 1, 3) p90=3.153 rmse=2.227 mae=1.636 p95=3.347 max=4.802
Top by bottleneck ratio:
  w=(2, 0, 1) p90=3.123 rmse=2.262 mae=1.667 p95=3.427 max=4.981 bneck=1.329
  w=(4, 0, 2) p90=3.123 rmse=2.262 mae=1.667 p95=3.427 max=4.981 bneck=1.329
  w=(2, 2, 1) p90=3.135 rmse=2.213 mae=1.617 p95=3.584 max=4.564 bneck=1.334
  w=(4, 4, 2) p90=3.135 rmse=2.213 mae=1.617 p95=3.584 max=4.564 bneck=1.334
  w=(4, 1, 2) p90=3.143 rmse=2.227 mae=1.634 p95=3.364 max=4.817 bneck=1.337
  w=(4, 1, 3) p90=3.153 rmse=2.227 mae=1.636 p95=3.347 max=4.802 bneck=1.342
The weight search is fairly flat , weights (2,2,1) for (ET, HGB, MLP) give rmse 2.213, mae 1.617, p90 3.135, p95 3.584, max 4.564. The p90 bottleneck ratio is ~1.33 on 5-fold. On the full-train scenario it'll be better. Given flatness, a balanced weight like ET:HGB:MLP = 2:1:2 or 2:2:1 is fine. I'll go with a robust, roughly-equal blend that keeps max low too. Let me pick weights ET=2, HGB=1, MLP=2 (balances p90 and keeps diversity), or (2,2,1). The differences are tiny. I'll use ET=2, HGB=2, MLP=1 style... Let me use a balanced (2,1,2) , but let me just pick (2,2,1) which had good rmse/mae/max. Actually for robustness to the unknown hidden set, I want a blend that is strong on ALL metrics, not overfit to 5-fold p90. Equal-ish weights are safest. Let me go with ET=2, HGB=1, MLP=2. Hmm, these are all so close it doesn't matter much. Let me use ET=2, HGB=2, MLP=1 (rmse 2.213, mae 1.617, max 4.564 , best max, good rmse/mae). Now let me finalize the production script. Key design decisions: 1. Features: features2 (rich physics features). Robust to any input. 2. Models: ExtraTrees (2 seeds), HistGBR (1-2), MLP (3 seeds). Blend. 3. Train on train + validation. 4. Predict on test_features.csv. 5. Write predictions.csv with exact columns. 6. Robustness: handle NaNs/infs in features, ensure finite outputs, string sample_id. Let me also make the script not too slow (grader re-runs it). ET 1000 trees x2, HGB, MLP x3 , should run in ~1-2 min. Fine. Let me also add a small safety: if test has few rows, still works. One more consideration: the task says "implausibly exact outputs receive 0.0" , meaning if predictions exactly match something (like if I accidentally output raw UCI labels), it's rejected. My ML predictions are fine (not exact). Also "Do not read or tamper with /tests, /grader..." , I won't. Let me also reconsider: should I include the MLP given it's stochastic and slower? It helped the blend notably (reduced mae and p90). Yes, include it with fixed seeds for reproducibility. Let me now also reconsider whether to add more seeds/bagging to reduce variance further. More ET seeds and MLP seeds = lower variance = tighter per-condition = better p90. Let me use ET with more estimators (1200) and 2 seeds, MLP 3 seeds. That adds robustness. Let me write the final script now. I'll embed the feature engineering directly (no external imports needed beyond sklearn) so it's self-contained. Let me write it carefully. Actually, let me reconsider the condition-aware smoothing one more time , it hurt because poly imposed bias. But a GENTLE smoothing (high-degree, or only averaging model predictions across seeds) is already done via ensemble. Skip explicit smoothing. Let me also reconsider: should I train models on the FULL feature set including raw_freq/raw_thick? Earlier for MLP/SVR I dropped raw (they're badly scaled , but StandardScaler handles scaling; still, raw_freq has huge range and after standardizing it's fine, but it's redundant with log_freq). For trees, raw features let them memorize. Let me keep features2 as-is (it includes raw_freq, raw_thick) for trees, and for MLP use the same (StandardScaler normalizes). Actually in features2 I have raw_freq and raw_thick. For the MLP, including raw_freq (highly correlated with log_freq) is redundant but harmless after scaling. To be safe and consistent, I'll use the full features2 for all models (the val_eval used features2 full for all and got good blend results: rmse 2.21). Wait, in val_eval.py I used F.Xy (features2, full including raw) for ALL models including MLP/SVR and the blend ET+HGB+SVR+MLP got rmse 2.207, mae 1.670, p90 3.22. And in make_oof I used Xnr (no raw) for MLP/SVR. Both similar. I'll use full features2 for all for simplicity. Let me write the final script. Let me structure: - FEATURES list (raw input columns). - make_features(df) -> DataFrame (features2 logic). - load data, build X, y. - fit models, blend, predict. - clip/sanitize, write. Let me write it.
The weight search is flat; a balanced blend (ET:HGB:MLP ≈ 2:2:1) gives rmse 2.21, mae 1.62, max 4.56. Since the real run trains on all 82 conditions (better than CV), this is my design. Let me write the self-contained production script.
str_replace_based_edit_tool
command: create
path: /app/train_and_predict.py
file_text: #!/usr/bin/env python3
"""Airfoil Self-Noise surrogate.

Trains a physics-informed ensemble (ExtraTrees + HistGradientBoosting + MLP)
on the labeled public data and writes calibrated predictions for the
grader-staged evaluation features.

The task holds out *complete* aerodynamic condition groups
``(attack_angle, chord_length, free_stream_velocity)``, so the model is
designed and blended to generalize to unseen physical regimes rather than to
interpolate nearby rows. Feature engineering follows the Brooks-Pope-Marcolini
(BPM) self-noise scalings (Strouhal/Reynolds numbers, log amplitude terms),
which extrapolate more gracefully than raw coordinates. The ensemble averages a
low-bias tree model, a boosted tree model, and smooth neural nets to shrink the
per-condition error tail that the grader penalizes (p90/p95/max condition RMSE).
"""

from pathlib import Path
import warnings

import numpy as np
import pandas as pd

from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler

warnings.filterwarnings("ignore")

DATA_DIR = Path("/app/data")
OUTPUT_DIR = Path("/app/output")
TARGET = "scaled_sound_pressure_level"
PREDICTION = "predicted_scaled_sound_pressure_level"
FEATURES = [
    "frequency",
    "attack_angle",
    "chord_length",
    "free_stream_velocity",
    "suction_side_displacement_thickness",
]


def make_features(df: pd.DataFrame) -> pd.DataFrame:
    """Physics-informed feature map (BPM self-noise scalings + interactions)."""
    f = np.asarray(df["frequency"], dtype=float)
    a = np.asarray(df["attack_angle"], dtype=float)
    c = np.asarray(df["chord_length"], dtype=float)
    u = np.asarray(df["free_stream_velocity"], dtype=float)
    d = np.asarray(df["suction_side_displacement_thickness"], dtype=float)

    # Guard against non-positive values before taking logs.
    eps = 1e-12
    f = np.clip(f, eps, None)
    c = np.clip(c, eps, None)
    u = np.clip(u, eps, None)
    d = np.clip(d, eps, None)

    lf = np.log10(f)
    ld = np.log10(d)
    lc = np.log10(c)
    lu = np.log10(u)
    nu = 1.5e-5  # kinematic viscosity of air (m^2/s)

    o = {}
    # Primary (log) coordinates.
    o["log_freq"] = lf
    o["attack_angle"] = a
    o["log_chord"] = lc
    o["log_vel"] = lu
    o["log_thick"] = ld
    # Dimensionless BPM-style groups.
    o["log_St_d"] = np.log10(f * d / u)      # displacement-thickness Strouhal
    o["log_St_c"] = np.log10(f * c / u)      # chord Strouhal
    o["log_Re_c"] = np.log10(c * u / nu)     # chord Reynolds
    o["log_Re_d"] = np.log10(d * u / nu)     # thickness Reynolds
    o["mach"] = u / 340.0
    o["d_over_c"] = d / c
    o["log_d_over_c"] = np.log10(d / c)
    # Interactions (let smooth models capture coupled trends).
    o["lf_angle"] = lf * a
    o["lf_ld"] = lf * ld
    o["lf_lc"] = lf * lc
    o["lf_lu"] = lf * lu
    o["a_ld"] = a * ld
    o["a_lc"] = a * lc
    o["a_lu"] = a * lu
    o["lf2"] = lf * lf
    o["angle2"] = a * a
    o["ld2"] = ld * ld
    o["sin_a"] = np.sin(np.radians(a))
    o["raw_freq"] = f
    o["raw_thick"] = d

    out = pd.DataFrame(o, index=df.index)
    return out.replace([np.inf, -np.inf], np.nan).fillna(0.0)


def load_labeled_data() -> pd.DataFrame:
    parts = [pd.read_csv(DATA_DIR / "train.csv")]
    validation_path = DATA_DIR / "validation.csv"
    if validation_path.exists():
        parts.append(pd.read_csv(validation_path))
    data = pd.concat(parts, ignore_index=True)
    # Keep only rows with a usable (finite) target.
    data = data[np.isfinite(pd.to_numeric(data[TARGET], errors="coerce"))]
    return data.reset_index(drop=True)


def load_evaluation_features() -> pd.DataFrame:
    test_path = DATA_DIR / "test_features.csv"
    if test_path.exists():
        return pd.read_csv(test_path)
    # Fallback for local runs without a 
…[truncated]
output
Existing file was successfully overwritten at /app/train_and_predict.py
Now let me test the script end-to-end. First, I'll simulate the grader: remove any existing predictions, run the script, check the output. But the placeholder test_features.csv == validation features (with labels known to me). So I can run the script, then compare predictions to the true validation labels to get a realistic metric estimate (though the model was trained on validation too, so this is optimistic/in-sample for those 15 conditions). That's fine for a sanity check of the pipeline. For a true held-out estimate, I'll rely on my earlier grouped CV. But let me at least verify the script runs and produces valid output. Let me run it and time it.
Now let me test the script end-to-end, simulating the grader (discard old predictions, re-run), and verify the output format.
bash
cd /app && rm -f output/predictions.csv && time python3 train_and_predict.py && echo "---OUTPUT---" && head -5 output/predictions.csv && echo "..." && wc -l output/predictions.csv
output
---OUTPUT---
sample_id,predicted_scaled_sound_pressure_level
af_val_0000,116.4554807596162
af_val_0001,124.95713396017285
af_val_0002,132.88160505368134
af_val_0003,124.4287633508136
...
41 output/predictions.csv
[stderr]
real	0m29.495s
user	0m32.360s
sys	0m0.950s
The script runs in ~30s and produces 40 predictions (41 lines with header). Now let me validate the output format and do sanity checks: 1. Exactly one row per sample_id. 2. Numeric and finite. 3. Columns correct. Let me also verify predictions are reasonable vs known validation labels (these 15 conditions were in training, so it's in-sample-ish, but the sample_ids af_val_* correspond to validation rows which ARE in my training set now , so this overlaps). This just sanity-checks magnitudes. Let me run validation checks.
The script runs in ~30s and outputs 40 well-formed predictions. Let me run format/sanity validation and confirm no input files were modified.
bash
cd /app && python3 -c "
import pandas as pd, numpy as np
p=pd.read_csv('output/predictions.csv')
tf=pd.read_csv('data/test_features.csv')
assert list(p.columns)==['sample_id','predicted_scaled_sound_pressure_level'], p.columns
assert len(p)==len(tf), (len(p),len(tf))
assert p['sample_id'].astype(str).tolist()==tf['sample_id'].astype(str).tolist(), 'id mismatch/order'
assert np.isfinite(p['predicted_scaled_sound_pressure_level']).all(), 'non-finite'
assert p['predicted_scaled_sound_pressure_level'].nunique()>5, 'looks constant'
print('Format checks PASSED. rows=',len(p))
print('pred range:',p.iloc[:,1].min().round(2),'to',p.iloc[:,1].max().round(2),'std',p.iloc[:,1].std().round(2))
# Compare to known validation labels (same ids) just as a magnitude sanity check
va=pd.read_csv('data/validation.csv').set_index('sample_id')['scaled_sound_pressure_level']
m=p.set_index('sample_id').join(va)
err=m['predicted_scaled_sound_pressure_level']-m['scaled_sound_pressure_level']
print('vs val labels (in-sample-ish) rmse=%.3f mae=%.3f'%(np.sqrt((err**2).mean()),err.abs().mean()))
"
output
Format checks PASSED. rows= 40
pred range: 114.85 to 137.8 std 6.38
vs val labels (in-sample-ish) rmse=0.662 mae=0.470
The format checks pass. The in-sample-ish rmse (0.66) just confirms the model fits (these conditions are in training now). Not a generalization estimate. Now, the critical concern remains: will this pass the hidden targets, especially p90<=2.35? My grouped-CV estimate suggests p90 ~2.7-3.2 when trained on all data. This is the bottleneck. Let me think harder about reducing p90. I have ~97k tokens. Let me make a focused effort on a genuinely better approach. Key realization revisited: The benchmark designers set p90<=2.35 as achievable. There must be an approach that does notably better on held-out conditions. Let me reconsider. One thing I haven't fully exploited: the TRANSDUCTIVE setting. At predict time, I have ALL hidden test rows (the full frequency sweeps for each hidden condition). This is valuable. Let me think about how to use unlabeled test data to improve predictions. Idea: The hidden test conditions each have a full frequency sweep. I can identify the test conditions (group test rows by snapped angle/chord/velocity). For each test condition, I know the exact (angle, chord, velocity, delta*) and the set of frequencies. Transductive technique that could genuinely help: For each test condition, the model predicts a spectral curve. The ERROR has a "level" component (bias) and "shape" component. I can't fix bias without labels. BUT, if I believe the training data's conditions span the space, I could use a NEAREST-CONDITION approach: find training conditions similar to the test condition and transfer their residual structure. Too speculative. Alternative high-value idea: Reduce per-condition VARIANCE (shape jitter) by averaging many diverse models AND by exploiting within-condition smoothness. Earlier polynomial smoothing hurt because it imposed a rigid global shape. But a GENTLE smoothing that only removes high-frequency jitter (not re-shaping) could help shape-dominated conditions. However, I found errors are bias-dominated, not jitter. So smoothing won't help. Let me reconsider the shape-dominated conditions (e.g., 17.4_0.0254_39.6 shape=3.65). The model's predicted curve shape is wrong. Why? Small chord (0.0254) at high angle (17.4). The spectrum at small chord extends to high frequency. Let me look at whether the model extrapolates the high-frequency behavior. Actually, let me reconsider: maybe the issue is that for some held-out conditions, the model is asked to extrapolate in frequency beyond what it saw FOR THAT delta*/chord. But frequency range is similar across conditions. Let me try yet another angle: instead of one global model, use the known physics that SPL curves are smooth and the RESIDUAL from a per-condition smooth fit is ~1.0. What if I fit the model, then for each test condition, re-fit a smooth low-order curve to the model's predictions but ANCHORED to reduce bias? No anchor without labels. I think I've exhausted the clever ideas given constraints. Let me instead maximize the ensemble's raw quality with more diversity and careful tuning, which incrementally helps p90. Let me reconsider whether a larger/different MLP or more seeds helps. Also whether adding a RandomForest and GradientBoosting increases diversity beneficially. Let me test a broader ensemble on the stable 20-fold CV (closest to real scenario) to pick the final blend. But 20-fold with MLP is slow. Let me do a 10-fold CV comparison of my CURRENT final blend vs a broader blend, to confirm I've got the best, using a background run. I'll measure the realistic metrics. Actually, given the trend (more training conditions → better), the most important thing is that my final model trains on all 82 conditions. My CV underestimates. Let me get the best estimate of the REAL scenario via Leave-One-Group-Out (LOGO) , train on 81 conditions, predict 1. That's exactly the deployment scenario (train on all available, predict unseen). LOGO over 82 conditions = 82 fits per model. ET is fast but MLP×3 would be slow (82×3 MLP fits). Let me d …[truncated]
Format is valid and no inputs modified. The remaining risk is the p90 bottleneck. Trees build their own interactions, so the many explicit product features may cause overfitting. Let me test whether a **leaner feature set generalizes better for trees**, while running a realistic 20-fold eval of the full blend in the background.
bash
cd /app && cat > /tmp/cv_blend20.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
sys.path.insert(0,'/app')
import train_and_predict as T
import pandas as pd, numpy as np
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('/app/data/train.csv'),pd.read_csv('/app/data/validation.csv')],ignore_index=True)
X=T.make_features(alld[T.FEATURES]); y=alld[T.TARGET].to_numpy(float); cond=condition_key(alld); groups=cond.values
gkf=GroupKFold(20); preds=np.zeros(len(y)); tw=0.0
mods=T.build_models()
for est,w in mods: tw+=w
for tri,tei in gkf.split(X,y,groups):
    acc=np.zeros(len(tei))
    for est,w in T.build_models():
        est.fit(X.iloc[tri],y[tri]); acc+=w*est.predict(X.iloc[tei])
    preds[tei]=acc/tw
m=metrics(y,preds,cond); cr=pd.DataFrame({'c':groups,'e':preds-y}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
print('FULL BLEND 20-fold:',{k:round(v,3) for k,v in m.items()},'frac<=2.35=%.2f'%(cr<=2.35).mean())
EOF
nohup python3 /tmp/cv_blend20.py > /tmp/blend20_log.txt 2>&1 &
echo "blend20 pid $!"
# meanwhile: lean vs rich features for ET (10-fold)
timeout 200 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('/app/data/train.csv'),pd.read_csv('/app/data/validation.csv')],ignore_index=True)
y=alld['scaled_sound_pressure_level'].to_numpy(float); cond=condition_key(alld); groups=cond.values
f=alld.frequency.values;a=alld.attack_angle.values;c=alld.chord_length.values;u=alld.free_stream_velocity.values;d=alld.suction_side_displacement_thickness.values
lf=np.log10(f);ld=np.log10(d);lc=np.log10(c);lu=np.log10(u)
lean=pd.DataFrame(dict(lf=lf,a=a,lc=lc,lu=lu,ld=ld,Std=np.log10(f*d/u),Stc=np.log10(f*c/u),Rec=np.log10(c*u/1.5e-5),Red=np.log10(d*u/1.5e-5),mach=u/340,doc=d/c))
import train_and_predict as T; rich=T.make_features(alld[T.FEATURES])
for name,X in [('lean',lean),('rich',rich)]:
    gkf=GroupKFold(10); p=np.zeros(len(y))
    for tri,tei in gkf.split(X,y,groups):
        p[tei]=ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=0).fit(X.iloc[tri],y[tri]).predict(X.iloc[tei])
    m=metrics(y,p,cond); cr=pd.DataFrame({'c':groups,'e':p-y}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'ET {name:4s} 10fold rmse={m[\"rmse\"]:.3f} mae={m[\"mae\"]:.3f} p90={m[\"p90\"]:.2f} p95={m[\"p95\"]:.2f} max={m[\"maxc\"]:.2f} frac<=2.35={(cr<=2.35).mean():.2f}')
"
output
blend20 pid 1920
ET lean 10fold rmse=2.378 mae=1.758 p90=3.52 p95=3.92 max=5.64 frac<=2.35=0.70
ET rich 10fold rmse=2.292 mae=1.662 p90=3.37 p95=4.01 max=5.49 frac<=2.35=0.71
Rich features are slightly better than lean for ET (rmse 2.29 vs 2.38, p90 3.37 vs 3.52). So keep rich features. Good , my current design is validated. Let me wait for the 20-fold full blend result (the most realistic estimate).
Rich features win for trees, confirming the design. Let me check the realistic 20-fold full-blend estimate.
bash
sleep 90 && cat /tmp/blend20_log.txt
output
<system>Tool ran without output or errors</system>
bash
sleep 120 && cat /tmp/blend20_log.txt
output
<system>Tool ran without output or errors</system>
Still running (20 folds × 6 models, MLP is slow). Let me wait a bit more.
bash
sleep 150 && cat /tmp/blend20_log.txt && echo "---" && ps aux | grep cv_blend20 | grep -v grep | wc -l
output
---
1
Still running (process count 1). MLP × 3 seeds × 20 folds = 60 MLP fits plus 40 ET (1200 trees) fits + 20 HGB. This is slow. Let me wait more.
bash
sleep 180 && cat /tmp/blend20_log.txt && echo "---running:" && ps aux | grep cv_blend20 | grep -v grep | wc -l
output
FULL BLEND 20-fold: {'rmse': 2.111, 'mae': 1.546, 'p90': 3.07, 'p95': 3.335, 'maxc': 4.992, 'ncond': 82} frac<=2.35=0.77
---running:
0
The realistic 20-fold full-blend estimate (train on ~78 conditions, close to the real 82): - rmse 2.111 (✓ <=2.25) - mae 1.546 (✓ <=1.55, just under!) - p90 3.07 (✗ need <=2.35) - p95 3.335 (✓ <=4.75) - max 4.992 (✓ <=5.60) - frac<=2.35 = 0.77 So 4 of 5 metrics pass in this realistic estimate. Only p90 (3.07) fails, needing 2.35. mae is right at the boundary (1.546). When trained on the FULL 82 conditions (real deployment, predicting a separate hidden set), metrics should be slightly better still. But p90 at 3.07 → even with improvement unlikely to reach 2.35 unless the hidden set is more favorable. So p90 is THE bottleneck, consistently ~3.0. I need a breakthrough on p90, or accept partial reward. Let me think very carefully about p90 one final time. p90 is the 90th percentile of per-condition RMSE. frac<=2.35 = 0.77 means 77% of conditions are good. I need 90%. The difference is ~10-13 conditions. The per-condition RMSE has a noise floor of ~1.0 (within-condition). A condition with perfect level+shape prediction still has RMSE ~1.0. The bad conditions have RMSE 2.4-5.0 due to level/shape extrapolation errors. Given the noise floor is 1.0, and targets want p90<=2.35, the designers' reference model must achieve per-condition bias+shape error small enough that sqrt(1.0² + err²)<=2.35 for 90% of conditions → err<=2.13 for 90%. My model achieves err<=2.13 for only 77%. To improve, I need better extrapolation for ~13% more conditions. Let me reconsider the noise floor estimate. Maybe within-condition noise is actually LOWER than 1.0 and I can fit shape better. Earlier I fit deg-4 poly per condition and got residual 1.0. But maybe the TRUE noise is lower and the poly (deg 4) couldn't capture the real shape. If noise is actually ~0.5, then the per-condition RMSE floor is 0.5, giving more headroom. Let me re-examine: fit higher-degree splines per condition. Actually, more importantly: maybe I should reconsider whether the reported metrics are even computed per-condition the way I think. Let me re-read: "hidden_p90_condition_rmse". Yes, per-condition RMSE, 90th percentile. Let me try ONE more modeling idea that targets extrapolation directly: a GAM-style model using SplineTransformer on the key physical variables WITH interaction terms, regularized. Smooth additive models extrapolate better than trees for the level/shape. Earlier pure spline-ridge was 3.0 rmse (underfit, additive only). Let me add the critical 2-way interactions via products of splines or via a richer basis. Actually, let me reconsider the whole thing. What if I ensemble the trees/MLP with a well-regularized high-degree polynomial ridge that extrapolates smoothly? The blend already includes MLP (smooth). Adding more smooth models of different types might reduce the tail. Hmm. Let me try adding a Huber/robust smooth model and a KNN in standardized physical space to the blend, and see if the 20-fold p90 improves. But I've seen individual weak models. Let me take a different, decisive approach: I'll accept that p90 ≈ 3.0 is near my ceiling with pure feature-based ML, and ensure the OTHER metrics are as strong as possible (they pass with margin), maximizing the reward floor. The reward is bottlenecked by the weakest metric; if p90 can't reach 0.50-reward threshold, at least the continuous reward for p90 at 3.07 vs 2.35... I don't know the exact reward curve, but closer is better. But wait , let me reconsider if the hidden set might genuinely be easier. My CV holds out RANDOM conditions including the hardest (high-angle stall, extreme chords). The actual hidden split was chosen ONCE. The validation set (the designated proxy) has p90 ~3.0 too. So the hidden set is probably similar. BUT , here's a thought: the benchmark is "calibrated." Maybe the calibration REDUCES the per-condition difficulty (smooths out the hard physics) so that a good model CAN hit p90 2.35. My data IS the calibrated data, so my CV should reflect that. And it shows p90 3.0. So either my …[truncated]
The realistic 20-fold estimate: **rmse 2.11 ✓, mae 1.55 ✓, p95 3.34 ✓, max 4.99 ✓**, with only **p90 3.07** missing (target 2.35). p90 is the sole bottleneck. Since smooth models should extrapolate the physics best, let me test a beefier multi-seed MLP ensemble (relu vs tanh) to see if it reduces the tail.
bash
cd /app && cat > /tmp/mlp_test.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
sys.path.insert(0,'/app'); import train_and_predict as T
import pandas as pd, numpy as np
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('/app/data/train.csv'),pd.read_csv('/app/data/validation.csv')],ignore_index=True)
X=T.make_features(alld[T.FEATURES]); y=alld[T.TARGET].to_numpy(float); cond=condition_key(alld); groups=cond.values
def cvpred(builder,nf=10):
    gkf=GroupKFold(nf); p=np.zeros(len(y))
    for tri,tei in gkf.split(X,y,groups):
        acc=np.zeros(len(tei)); ms=builder()
        for m in ms: m.fit(X.iloc[tri],y[tri]); acc+=m.predict(X.iloc[tei])
        p[tei]=acc/len(ms)
    return p
def rep(name,p):
    m=metrics(y,p,cond); cr=pd.DataFrame({'c':groups,'e':p-y}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'{name:22s} rmse={m["rmse"]:.3f} mae={m["mae"]:.3f} p90={m["p90"]:.2f} p95={m["p95"]:.2f} max={m["maxc"]:.2f} frac={ (cr<=2.35).mean():.2f}',flush=True)
    return p
def relu(): return [make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=a,alpha=1e-3,max_iter=4000,random_state=s)) for s,a in enumerate([(128,128,64),(200,100),(150,150,75),(256,128,64),(180,120,60)])]
def tanh(): return [make_pipeline(StandardScaler(),MLPRegressor(hidden_layer_sizes=a,activation='tanh',alpha=3e-3,max_iter=4000,random_state=s)) for s,a in enumerate([(128,128,64),(200,100),(150,150,75),(256,128,64),(180,120,60)])]
pr=rep('MLP relu x5',cvpred(relu))
pt=rep('MLP tanh x5',cvpred(tanh))
rep('MLP relu+tanh',(pr+pt)/2)
np.savez('/tmp/mlp_oof.npz',relu=pr,tanh=pt,y=y,cond=groups)
EOF
nohup python3 /tmp/mlp_test.py > /tmp/mlp_log.txt 2>&1 &
echo "pid $!"; sleep 200; cat /tmp/mlp_log.txt
output
pid 2572
bash
sleep 120 && cat /tmp/mlp_log.txt && echo "running:" && ps aux|grep mlp_test|grep -v grep|wc -l
output
MLP relu x5            rmse=2.584 mae=1.882 p90=3.91 p95=4.28 max=7.06 frac=0.59
running:
1
MLP relu x5 alone: rmse 2.58, p90 3.91 , worse than the blend. So pure MLP isn't better. Let me wait for tanh but I suspect similar. The MLP is not the savior; the blend works because trees+MLP diversity helps. Let me stop waiting on this; MLP alone is weaker. The blend (trees + MLP) at p90 3.07 is my best. Let me accept the modeling ceiling and think about whether there's anything structurally different I can do to break p90. Let me reconsider the problem from the data-generation perspective ONE more time. The features are noisy versions of the UCI grid. The target is "calibrated." What if the calibration means: target = f(TRUE features) + noise, where TRUE features are the clean grid values, and the NOISE added to features is independent? Then when I train on noisy features, I have errors-in-variables, which biases/blurs the learned function. If I could recover the TRUE (clean) features by snapping, the function would be cleaner. I showed within-condition feature noise is tiny (0.1-0.5%). So snapping barely changes features. But the TARGET might depend on clean features. Since noise is tiny, this matters little. Hmm. Let me reconsider the within-condition noise floor (1.0) , is it really irreducible label noise, or structure? Let me fit a more flexible per-condition model (e.g., smoothing spline / higher degree) and see if residual drops below 1.0. If residual stays ~1.0, it's real label noise → p90 floor is real. If it drops, there's fittable structure. Let me check with higher-degree and GAM per condition. Actually with ~14 points per condition, deg-4 poly already has 5 params. Going higher risks overfit. Let me instead look at whether the residuals are autocorrelated in frequency (structure) or random (noise). If random → irreducible. Let me just check the residual more carefully: fit deg-5 per condition and report. Quick. Actually, this is somewhat academic. The key practical question: can I reduce p90 below 2.35? My evidence says ~3.0 is my ceiling. Let me make peace with maximizing all metrics and ensuring robustness, while keeping the best p90 I can. Actually , wait. Let me reconsider the reward structure implications. "Reward is bottlenecked by the weakest required metric." and targets. If p90 can't reach 2.35, I won't hit reward 0.50. That means "not solved." But maybe I'm being too pessimistic about the hidden set. Let me reconsider: my CV/val p90 estimates are based on MY condition grouping, which MERGES close angle pairs (12.3/12.6, 15.4/15.6). Merging conditions AVERAGES their rows. A merged group with rows from two true conditions might have HIGHER RMSE if the model predicts them differently, OR the merge might hide a bad condition. More importantly, the grader's TRUE grouping (finer) would SPLIT these, creating MORE conditions. With more conditions, the 90th percentile is computed over more groups. If the grader uses finer grouping (each true condition separate), then: - More total conditions (maybe ~100+ for the full set, or the hidden set has more). - The per-condition RMSE for a true condition (all same physics) might be LOWER or similar. Actually finer grouping would generally INCREASE p90 (smaller groups = noisier RMSE, more extreme percentiles). So my merging might make my p90 estimate OPTIMISTIC relative to a finer grader grouping. That's concerning. Conversely, if the grader's grouping is what I use (snapping), then my estimate holds. I can't resolve this. Let me just maximize model quality. Let me reconsider: is there any way to exploit that the grader RE-RUNS my script with the hidden test staged? The hidden test features are available to my script at runtime. I could do transductive learning. Let me think about a CONCRETE transductive method that reduces per-condition error: Semi-supervised idea via "condition-consistent prediction": For each test condition (grouped by snapped angle/chord/velocity), the predictions should form a smooth spectral curve. I can enforce this. But I sho …[truncated]
Pure MLP is weaker (p90 3.91) , the blend's diversity is what matters. Let me do principled **forward-selection blending** over all 9 saved base-model OOFs to find the combination that minimizes the p90 bottleneck while keeping other metrics in range.
bash
cd /app && timeout 120 python3 -c "
import numpy as np, pandas as pd, sys; sys.path.insert(0,'/tmp')
from cv_harness import metrics
d=np.load('/tmp/oof_all.npz',allow_pickle=True)
y=d['y']; cond=d['cond']
names=[k for k in d.files if k not in ('y','cond')]
P={n:d[n] for n in names}
def sc(p):
    m=metrics(y,p,cond)
    return m
# greedy forward selection minimizing p90 (tie-break rmse), allow repeats (weights)
sel=[]; 
cur=np.zeros(len(y))
best_metric=1e9
for step in range(8):
    bestn=None; bestm=None; bestp=None
    for n in names:
        p=(cur*len(sel)+P[n])/(len(sel)+1)
        m=sc(p)
        key=(m['p90'],m['rmse'],m['mae'])
        if bestm is None or key<bestm:
            bestm=key; bestn=n; bestp=p; bestmet=m
    sel.append(bestn); cur=bestp
    print(f'step{step+1} add {bestn:5s} -> rmse={bestmet[\"rmse\"]:.3f} mae={bestmet[\"mae\"]:.3f} p90={bestmet[\"p90\"]:.2f} p95={bestmet[\"p95\"]:.2f} max={bestmet[\"maxc\"]:.2f}')
from collections import Counter
print('selection counts:',Counter(sel))
"
output
step1 add ETnr  -> rmse=2.407 mae=1.775 p90=3.37 p95=3.99 max=5.63
step2 add HGB   -> rmse=2.311 mae=1.687 p90=3.31 p95=3.97 max=5.09
step3 add MLP1  -> rmse=2.249 mae=1.636 p90=3.31 p95=3.72 max=4.95
step4 add SVR   -> rmse=2.203 mae=1.594 p90=3.12 p95=3.60 max=5.59
step5 add HGB   -> rmse=2.201 mae=1.590 p90=3.12 p95=3.52 max=5.50
step6 add SVR   -> rmse=2.221 mae=1.595 p90=3.05 p95=3.68 max=6.00
step7 add SVR   -> rmse=2.261 mae=1.617 p90=3.04 p95=3.80 max=6.37
step8 add ET    -> rmse=2.228 mae=1.601 p90=3.00 p95=3.63 max=6.03
selection counts: Counter({'SVR': 3, 'HGB': 2, 'ETnr': 1, 'MLP1': 1, 'ET': 1})
Forward selection on 5-fold OOF: the best balanced point is around step 4-5: - step4 (ETnr+HGB+MLP1+SVR): rmse 2.203, mae 1.594, p90 3.12, p95 3.60, max 5.59. - step5 (add HGB): rmse 2.201, mae 1.590, p90 3.12, p95 3.52, max 5.50. Adding more SVR pushes p90 down to 3.00 but max blows up to 6.0+ (SVR has high max). So SVR trades p90 for max. Not worth it given max target 5.60. This is all consistent: p90 floor ~3.0-3.1 on 5-fold. The 20-fold (more training) gave 3.07. On full training, maybe ~2.8-2.9. I've now confirmed from multiple angles that p90 ≈ 3.0 is my ceiling. I cannot seem to break below ~2.8 for p90 with available methods/data. Let me make a strategic decision about the final model. The 20-fold estimate of my current script blend: rmse 2.11, mae 1.55, p90 3.07, p95 3.34, max 4.99. This is a good, balanced result that passes 4/5 metrics with margin and has the best p90 I can reliably get WITHOUT inflating max. The forward-selection suggests my current blend (ET×2, HGB×2weight, MLP×3) is already near-optimal. Including SVR reduces p90 slightly but risks max. I'll keep my current blend but maybe add one SVR with modest weight to nudge p90 without blowing max. Let me check: my current blend has max 4.99 (margin to 5.60). Adding a little SVR might reduce p90 to ~2.9 while keeping max < 5.60. But SVR's high max is a risk on the HIDDEN set (unknown conditions could trigger SVR extrapolation blowup). Robustness matters , "hidden_max_condition_rmse <= 5.60" must hold. SVR's instability (max 8+ in some CV) is dangerous. I'll be cautious: either exclude SVR or give it small weight. Given the risk, let me keep my robust blend (trees + MLP, no SVR) which had max 4.99 , safe margin. The p90 3.07 is the bottleneck regardless. Now, let me reconsider whether to push p90 harder via a fundamentally better idea, OR accept and finalize. I have ~86k tokens. Let me make one last genuine attempt at a transductive/semi-supervised improvement, since that's the only lever that could structurally help, and it directly uses the grader's provision of test features at runtime. Transductive plan: Instance weighting. Upweight training rows whose conditions are similar (in physical feature space) to the test conditions. This focuses the model on the regions of feature space relevant to the hidden test, potentially reducing bias there. But actually, this only helps if test conditions cluster in a specific region; if they span the whole space (like validation does), weighting ≈ uniform. The hidden conditions likely span the space. So limited benefit. Alternative transductive idea: self-training with confidence. Predict test, add high-confidence test pseudo-labels to training, retrain. For regression, "confidence" = ensemble agreement. Rows where all models agree are likely accurate; adding them as pseudo-labels reinforces structure and can slightly improve smoothness/consistency. But it mostly reinforces existing bias. Low expected value, some risk. I think these are unlikely to help meaningfully and add risk. Let me NOT do transductive tricks that could backfire. Let me instead make sure my solution is as robust and well-rounded as possible, and finalize. Actually, let me reconsider one more legitimate modeling improvement: the target could benefit from modeling in a way that reduces the worst conditions. The worst conditions are high-angle (stall) and high-velocity. What if I add a few more targeted features for stall (e.g., angle relative to a stall threshold, angle×chord interactions that capture separation)? I have angle2, a_lc, a_ld. Let me add a_lc2, higher angle terms, and a "high angle indicator × features." Probably trees handle this. Let me accept my model. Let me reconsider the final blend weights once more to ensure best p90 without max risk. From forward selection, ETnr (ExtraTrees without raw features, seed 1) appeared first , interesting. My current script uses ET with raw features (seeds 0,1). Let me consider includin …[truncated]
Forward selection confirms p90 plateaus ~3.0; adding SVR lowers p90 slightly but inflates max (risky on unseen data), so I'll avoid SVR for robustness. The safest reliable gains come from more ensemble members (variance reduction helps mae and p90). Let me enhance the ensemble with more seeds and a second HGB config, then validate.
str_replace_based_edit_tool
command: str_replace
path: /app/train_and_predict.py
old_str: def build_models():
    """(estimator, integer blend weight) pairs."""
    models = []
    # Low-bias randomized trees (two seeds for variance reduction).
    for seed in (0, 1):
        models.append((
            ExtraTreesRegressor(
                n_estimators=1200, max_features=0.6, min_samples_leaf=1,
                n_jobs=-1, random_state=seed,
            ),
            1,
        ))
    # Boosted trees (bias reduction, different inductive bias).
    models.append((
        HistGradientBoostingRegressor(
            max_iter=800, learning_rate=0.04, max_leaf_nodes=31,
            l2_regularization=1.0, min_samples_leaf=15, random_state=0,
        ),
        2,
    ))
    # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75)]
    for seed, arch in enumerate(archs):
        models.append((
            make_pipeline(
                StandardScaler(),
                MLPRegressor(
                    hidden_layer_sizes=arch, activation="relu", alpha=1e-3,
                    max_iter=4000, random_state=seed,
                ),
            ),
            1,
        ))
    return models
new_str: def build_models():
    """(estimator, integer blend weight) pairs.

    The ensemble balances total weight between low-variance randomized trees
    (ExtraTrees), bias-correcting boosted trees (HistGBR), and smooth neural
    nets (MLP). Multiple seeds per family reduce variance, which tightens the
    per-condition error tail (p90/p95) on held-out aerodynamic regimes.
    SVR/kernel models are deliberately excluded: they gave occasional large
    single-condition blow-ups that endanger the max-condition-RMSE budget.
    """
    models = []
    # Low-bias randomized trees (several seeds for variance reduction).
    for seed in (0, 1, 2):
        models.append((
            ExtraTreesRegressor(
                n_estimators=1200, max_features=0.6, min_samples_leaf=1,
                n_jobs=-1, random_state=seed,
            ),
            1,
        ))
    # Boosted trees (two complementary configs for diversity).
    models.append((
        HistGradientBoostingRegressor(
            max_iter=800, learning_rate=0.04, max_leaf_nodes=31,
            l2_regularization=1.0, min_samples_leaf=15, random_state=0,
        ),
        1,
    ))
    models.append((
        HistGradientBoostingRegressor(
            max_iter=1000, learning_rate=0.03, max_leaf_nodes=63,
            l2_regularization=2.0, min_samples_leaf=20, random_state=1,
        ),
        1,
    ))
    # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64)]
    for seed, arch in enumerate(archs):
        models.append((
            make_pipeline(
                StandardScaler(),
                MLPRegressor(
                    hidden_layer_sizes=arch, activation="relu", alpha=1e-3,
                    max_iter=4000, random_state=seed,
                ),
            ),
            1,
        ))
    return models
output
The file /app/train_and_predict.py has been edited successfully.
Now let me validate the enhanced blend via 10-fold CV (faster than 20-fold) to confirm it's comparable or better than before, and run the script end-to-end. Let me run the 10-fold CV of the exact new build_models() in the background, and also run the script to ensure it still works. Let me run the script first (quick check it works with new models).
Let me validate the enhanced ensemble end-to-end and via a realistic 10-fold CV of the exact `build_models()` used by the script.
bash
cd /app && rm -f output/predictions.csv && time python3 train_and_predict.py && python3 -c "
import pandas as pd, numpy as np
p=pd.read_csv('output/predictions.csv'); tf=pd.read_csv('data/test_features.csv')
assert list(p.columns)==['sample_id','predicted_scaled_sound_pressure_level']
assert p['sample_id'].astype(str).tolist()==tf['sample_id'].astype(str).tolist()
assert np.isfinite(p.iloc[:,1]).all() and p.iloc[:,1].nunique()>5
print('OK rows',len(p),'range',round(p.iloc[:,1].min(),2),round(p.iloc[:,1].max(),2))
"
output
OK rows 40 range 114.82 137.86
[stderr]
real	1m9.675s
user	0m56.690s
sys	0m1.450s
Script runs in ~70s and produces valid output. Now let me run the realistic 10-fold CV of the exact build_models() blend to confirm metrics. Let me background it.
Script runs in ~70s with valid output. Now let me run a realistic 10-fold CV of the exact enhanced blend to confirm the metrics held or improved.
bash
cd /app && cat > /tmp/cv_final2.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
sys.path.insert(0,'/app'); import train_and_predict as T
import pandas as pd, numpy as np
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('/app/data/train.csv'),pd.read_csv('/app/data/validation.csv')],ignore_index=True)
X=T.make_features(alld[T.FEATURES]); y=alld[T.TARGET].to_numpy(float); cond=condition_key(alld); groups=cond.values
tw=sum(w for _,w in T.build_models())
for nf in [10]:
    gkf=GroupKFold(nf); preds=np.zeros(len(y))
    for tri,tei in gkf.split(X,y,groups):
        acc=np.zeros(len(tei))
        for est,w in T.build_models():
            est.fit(X.iloc[tri],y[tri]); acc+=w*est.predict(X.iloc[tei])
        preds[tei]=acc/tw
    m=metrics(y,preds,cond); cr=pd.DataFrame({'c':groups,'e':preds-y}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'ENHANCED BLEND {nf}-fold:',{k:round(v,3) for k,v in m.items()},'frac<=2.35=%.2f'%(cr<=2.35).mean())
    tgt=dict(rmse=2.25,mae=1.55,p90=2.35,p95=4.75,maxc=5.60)
    print('pass:',{k:(round(m[k],3),'<=',tgt[k],m[k]<=tgt[k]) for k in tgt})
EOF
nohup python3 /tmp/cv_final2.py > /tmp/cvf2.txt 2>&1 &
echo "pid $!"; sleep 230; cat /tmp/cvf2.txt
output
pid 2656
bash
sleep 60 && cat /tmp/cvf2.txt && echo "running:" && ps aux|grep cv_final2|grep -v grep|wc -l
output
running:
1
bash
sleep 120 && cat /tmp/cvf2.txt && echo "running:" && ps aux|grep cv_final2|grep -v grep|wc -l
output
running:
1
10-fold with the enhanced blend (9 models, MLP is slow) is taking a while. Let me wait more.
bash
sleep 120 && cat /tmp/cvf2.txt && echo "running:" && ps aux|grep cv_final2|grep -v grep|wc -l
output
ENHANCED BLEND 10-fold: {'rmse': 2.211, 'mae': 1.614, 'p90': 3.12, 'p95': 3.378, 'maxc': 5.678, 'ncond': 82} frac<=2.35=0.74
pass: {'rmse': (2.211, '<=', 2.25, True), 'mae': (1.614, '<=', 1.55, False), 'p90': (3.12, '<=', 2.35, False), 'p95': (3.378, '<=', 4.75, True), 'maxc': (5.678, '<=', 5.6, False)}
running:
0
Hmm, the 10-fold enhanced blend: rmse 2.211, mae 1.614, p90 3.12, p95 3.378, max 5.678. The max (5.678) is now slightly OVER 5.60! That's worse than the 20-fold result (4.99). Wait, this is 10-fold (train ~73 conditions) vs the earlier 20-fold (train ~78). The 10-fold trains on fewer conditions, so metrics are worse. The max 5.678 at 10-fold is concerning, but at 20-fold (more training, closer to real) it was 4.99. The real scenario trains on all 82, so max should be lower than both. But the second HGB config (deeper, max_leaf_nodes=63) might have increased the max by overfitting. Let me compare: earlier 20-fold with the SIMPLER blend (2 ET, 1 HGB weight2, 3 MLP) gave max 4.99 at 20-fold. This enhanced blend at 10-fold gives max 5.678. Different fold counts make direct comparison hard. The deeper HGB (leaf 63) may be adding variance/overfitting, hurting max. Let me reconsider , I added it for diversity but it may hurt robustness on the max-condition metric. Given max is a hard constraint (<=5.60), I should be conservative. Let me revert to the simpler, validated blend that gave the clean 20-fold result (rmse 2.11, mae 1.55, p90 3.07, p95 3.34, max 4.99). That was: ET×2 (seeds 0,1, w1), HGB×1 (w2), MLP×3 (w1). That's the SAFEST validated config. But wait , the difference could just be 10-fold vs 20-fold. Let me not over-react to one 10-fold number. However, max 5.678 > 5.60 even at 10-fold is a yellow flag. The deeper HGB config is the main change that could cause higher max. Let me remove the second (deeper) HGB config and the extra ET seed / extra MLP to return to the validated configuration, OR keep moderate enhancements but drop the risky deeper HGB. Let me think about what's safest and best. The original validated blend (20-fold: max 4.99) is my most trustworthy result. Let me revert to essentially that, but keep the modest variance-reduction improvements that are SAFE (more seeds of the SAME well-behaved models, not a new riskier deeper HGB). Safe enhanced config: - ET seeds 0,1,2 (w1 each) , more seeds, same safe model. - HGB (the original safe config, max_leaf_nodes=31) weight 2. - MLP seeds 0-3 (4 archs, w1 each). This keeps the robust models, adds variance reduction, and removes the risky deeper HGB. Total weight: ET 3, HGB 2, MLP 4. Actually, let me reconsider weights. The original had HGB weight 2 with only 1 HGB. Let me keep HGB weight 2 (single safe config) for balance: ET 3 + HGB 2 + MLP 4 = 9. Hmm, but more MLP weight (4) vs trees (5) , balanced. Earlier MLP-heavy slightly increased rmse but helped p90. Let me keep balanced. Let me also reconsider: should I reduce to the EXACT validated 20-fold config to be safe? That config gave the best numbers. The only reason to change is variance reduction from more seeds, which is genuinely safe. Let me do the safe-enhanced config and re-validate with 20-fold (the realistic estimate) to confirm max stays < 5.60 with margin. Given time, let me update to the safe config (remove deeper HGB, keep single safe HGB weight 2, ET 3 seeds, MLP 4 seeds) and run a 20-fold validation (the realistic one). The 20-fold takes ~6-7 min though. Let me instead run 15-fold as a compromise (~4-5 min) for a realistic estimate. Actually, let me just run 20-fold in background and wait, since getting max right is critical. Let me update the script first.
The deeper second HGB config pushed max-condition RMSE to 5.68 (over the 5.60 budget). Since max is a hard constraint, I'll drop that riskier config and keep only the well-behaved HGB, while retaining the safe variance-reduction (more ET/MLP seeds).
str_replace_based_edit_tool
command: str_replace
path: /app/train_and_predict.py
old_str:     # Boosted trees (two complementary configs for diversity).
    models.append((
        HistGradientBoostingRegressor(
            max_iter=800, learning_rate=0.04, max_leaf_nodes=31,
            l2_regularization=1.0, min_samples_leaf=15, random_state=0,
        ),
        1,
    ))
    models.append((
        HistGradientBoostingRegressor(
            max_iter=1000, learning_rate=0.03, max_leaf_nodes=63,
            l2_regularization=2.0, min_samples_leaf=20, random_state=1,
        ),
        1,
    ))
    # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64)]
new_str:     # Boosted trees (bias correction; a single well-regularized config is used
    # because deeper/larger boosting configs produced occasional large
    # single-condition errors that threatened the max-condition-RMSE budget).
    models.append((
        HistGradientBoostingRegressor(
            max_iter=800, learning_rate=0.04, max_leaf_nodes=31,
            l2_regularization=1.0, min_samples_leaf=15, random_state=0,
        ),
        2,
    ))
    # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64)]
output
The file /app/train_and_predict.py has been edited successfully.
Now let me run a realistic 20-fold CV of this safe configuration (closest to the real train-on-all scenario) to confirm all metrics, especially that max stays within budget.
bash
cd /app && sed 's/\[10\]/[20]/' /tmp/cv_final2.py > /tmp/cv_final3.py && nohup python3 /tmp/cv_final3.py > /tmp/cvf3.txt 2>&1 & echo "pid $!"
output
pid 3014
This 20-fold will take ~6-7 minutes (20 folds × 7 models, MLP slow). Let me wait. Meanwhile, let me review the final script to ensure correctness and robustness.
While that runs (~6-7 min), let me review the full final script for correctness and robustness.
bash
cd /app && cat train_and_predict.py
output
#!/usr/bin/env python3
"""Airfoil Self-Noise surrogate.

Trains a physics-informed ensemble (ExtraTrees + HistGradientBoosting + MLP)
on the labeled public data and writes calibrated predictions for the
grader-staged evaluation features.

The task holds out *complete* aerodynamic condition groups
``(attack_angle, chord_length, free_stream_velocity)``, so the model is
designed and blended to generalize to unseen physical regimes rather than to
interpolate nearby rows. Feature engineering follows the Brooks-Pope-Marcolini
(BPM) self-noise scalings (Strouhal/Reynolds numbers, log amplitude terms),
which extrapolate more gracefully than raw coordinates. The ensemble averages a
low-bias tree model, a boosted tree model, and smooth neural nets to shrink the
per-condition error tail that the grader penalizes (p90/p95/max condition RMSE).
"""

from pathlib import Path
import warnings

import numpy as np
import pandas as pd

from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler

warnings.filterwarnings("ignore")

DATA_DIR = Path("/app/data")
OUTPUT_DIR = Path("/app/output")
TARGET = "scaled_sound_pressure_level"
PREDICTION = "predicted_scaled_sound_pressure_level"
FEATURES = [
    "frequency",
    "attack_angle",
    "chord_length",
    "free_stream_velocity",
    "suction_side_displacement_thickness",
]


def make_features(df: pd.DataFrame) -> pd.DataFrame:
    """Physics-informed feature map (BPM self-noise scalings + interactions)."""
    f = np.asarray(df["frequency"], dtype=float)
    a = np.asarray(df["attack_angle"], dtype=float)
    c = np.asarray(df["chord_length"], dtype=float)
    u = np.asarray(df["free_stream_velocity"], dtype=float)
    d = np.asarray(df["suction_side_displacement_thickness"], dtype=float)

    # Guard against non-positive values before taking logs.
    eps = 1e-12
    f = np.clip(f, eps, None)
    c = np.clip(c, eps, None)
    u = np.clip(u, eps, None)
    d = np.clip(d, eps, None)

    lf = np.log10(f)
    ld = np.log10(d)
    lc = np.log10(c)
    lu = np.log10(u)
    nu = 1.5e-5  # kinematic viscosity of air (m^2/s)

    o = {}
    # Primary (log) coordinates.
    o["log_freq"] = lf
    o["attack_angle"] = a
    o["log_chord"] = lc
    o["log_vel"] = lu
    o["log_thick"] = ld
    # Dimensionless BPM-style groups.
    o["log_St_d"] = np.log10(f * d / u)      # displacement-thickness Strouhal
    o["log_St_c"] = np.log10(f * c / u)      # chord Strouhal
    o["log_Re_c"] = np.log10(c * u / nu)     # chord Reynolds
    o["log_Re_d"] = np.log10(d * u / nu)     # thickness Reynolds
    o["mach"] = u / 340.0
    o["d_over_c"] = d / c
    o["log_d_over_c"] = np.log10(d / c)
    # Interactions (let smooth models capture coupled trends).
    o["lf_angle"] = lf * a
    o["lf_ld"] = lf * ld
    o["lf_lc"] = lf * lc
    o["lf_lu"] = lf * lu
    o["a_ld"] = a * ld
    o["a_lc"] = a * lc
    o["a_lu"] = a * lu
    o["lf2"] = lf * lf
    o["angle2"] = a * a
    o["ld2"] = ld * ld
    o["sin_a"] = np.sin(np.radians(a))
    o["raw_freq"] = f
    o["raw_thick"] = d

    out = pd.DataFrame(o, index=df.index)
    return out.replace([np.inf, -np.inf], np.nan).fillna(0.0)


def load_labeled_data() -> pd.DataFrame:
    parts = [pd.read_csv(DATA_DIR / "train.csv")]
    validation_path = DATA_DIR / "validation.csv"
    if validation_path.exists():
        parts.append(pd.read_csv(validation_path))
    data = pd.concat(parts, ignore_index=True)
    # Keep only rows with a usable (finite) target.
    data = data[np.isfinite(pd.to_numeric(data[TARGET], errors="coerce"))]
    return data.reset_index(drop=True)


def load_evaluation_features() -> pd.DataFrame:
    test_path = DATA_DIR / "test_features.csv"
    if test_path.exists():
        return pd.read_csv(test_path)
    # Fallback for local runs without a staged test file.
    validation = pd.read_csv(DATA_DIR / "
…[truncated]
The script looks good and robust. Let me consider edge cases: 1. The grader stages hidden rows at test_features.csv with the same schema. My script reads it, builds features, predicts. Good. 2. If test_features has extra columns or different order , I select by FEATURES names, so order doesn't matter. Good. 3. sample_id as string , good. 4. Finite predictions + clipping , good. 5. Doesn't modify input files , correct, only reads. 6. Doesn't touch /tests, /grader etc. , correct. One concern: the grader "discards any pre-existing /app/output/predictions.csv". My script writes fresh. Good. Another: reproducibility. The MLP uses random_state, ExtraTrees uses random_state. HGB deterministic. So predictions are reproducible. Good (avoids "implausibly exact" , these are model outputs, fine). Let me also double check: the task says predictions must not be "misaligned" , I output sample_id from the evaluation frame in order, matching. Good. Let me wait for the 20-fold result to confirm metrics, especially max < 5.60. Let me reconsider the p90 situation strategically while waiting. My realistic estimate is p90 ~3.0. I've been unable to break this. Let me accept it but consider: is there a legitimate way to reduce the per-condition error for the worst ~20% that I haven't tried? One more idea worth testing cheaply: post-hoc per-condition bias is unknown, but the GLOBAL calibration could be off. Also, maybe quantile considerations. No. Actually, let me reconsider the possibility that my condition grouping (which merges 12.3/12.6 and 15.4/15.6) inflates some per-condition RMSEs because I'm computing RMSE over a MERGED group that spans two physically distinct conditions with different levels. If the grader uses finer grouping, those merged groups would split and each might have LOWER RMSE. Let me test: compute metrics with a FINER angle grouping (using the actual UCI angle pairs 12.3 vs 12.6, 15.4 vs 15.6 distinguished) and see if p90 changes. But my snapping can't reliably distinguish 12.3 from 12.6 given noise ~0.35. Let me instead test the OPPOSITE: does finer vs coarser grouping change p90 much? Let me compute p90 under a few grouping granularities using my existing 20-fold OOF (once it's done) , actually I don't save OOF in cv_final3. Let me reconsider , this is getting deep. Let me just wait for the result and finalize. The honest situation: I have a strong, robust, well-engineered solution that passes 4/5 metrics comfortably and is at ~3.0 on p90 (target 2.35). This is likely the best achievable with straightforward ML on this data, and represents a solid, defensible submission. Actually, let me reconsider whether there's a data issue making p90 hard: the worst conditions are high-angle (stall). Let me check how many conditions in the dataset are high-angle and whether they're systematically harder. If the hidden set has FEWER high-angle conditions, p90 would be better. I can't control that. Let me reconsider if I should try to improve the stall-regime predictions with a dedicated feature. In BPM, separation-stall noise becomes dominant when angle exceeds a threshold (~12.5° for the switch, and there's a "deep stall" at higher angles). Let me add features capturing proximity to stall: e.g., relu(angle - 12.5), relu(angle - 17), and interactions with chord. These could help trees/MLP model the stall transition, reducing bias on high-angle conditions. Let me test adding stall features to see if they reduce p90/max on CV. Quick test with ET on 10-fold. Actually, let me wait for the current 20-fold first (to not interfere with CPU). Let me check on it.
Let me check on the 20-fold validation run.
bash
sleep 60 && cat /tmp/cvf3.txt && echo "running:" && ps aux|grep cv_final3|grep -v grep|wc -l
output
running:
1
Still running. Let me wait more. The 20-fold with 7 models (3 ET, 1 HGB, 4 MLP) × 20 folds is heavy. Let me wait.
bash
sleep 200 && cat /tmp/cvf3.txt && echo "running:" && ps aux|grep cv_final3|grep -v grep|wc -l
output
running:
1
bash
sleep 200 && cat /tmp/cvf3.txt && echo "running:" && ps aux|grep cv_final3|grep -v grep|wc -l
output
running:
1
This is taking very long (>10 min). The 4 MLPs × 20 folds × 4000 iters is the bottleneck. Let me wait a bit more, but if it takes too long I'll kill it and do a faster estimate. Let me give it another couple minutes.
bash
sleep 180 && cat /tmp/cvf3.txt && echo "running:" && ps aux|grep cv_final3|grep -v grep|wc -l
output
running:
1
It's taking over 13 minutes. The MLPs with max_iter=4000 are slow. Let me wait a little more, but this is eating my budget. Let me check once more and if not done, kill and accept the 20-fold result I already have from the earlier simpler blend (which is very close to this config). Actually, the earlier 20-fold result (simpler blend: 2 ET + 1 HGB(w2) + 3 MLP) was: rmse 2.111, mae 1.546, p90 3.07, p95 3.335, max 4.992. The current config is nearly identical (3 ET + 1 HGB(w2) + 4 MLP) , just one more ET seed and one more MLP seed for variance reduction. It should give essentially the same or marginally better/tighter metrics, with max safely < 5.60. Let me wait one more round then decide.
bash
sleep 120 && cat /tmp/cvf3.txt && echo "running:" && ps aux|grep cv_final3|grep -v grep|wc -l
output
ENHANCED BLEND 20-fold: {'rmse': 2.124, 'mae': 1.557, 'p90': 3.092, 'p95': 3.346, 'maxc': 5.277, 'ncond': 82} frac<=2.35=0.77
pass: {'rmse': (2.124, '<=', 2.25, True), 'mae': (1.557, '<=', 1.55, False), 'p90': (3.092, '<=', 2.35, False), 'p95': (3.346, '<=', 4.75, True), 'maxc': (5.277, '<=', 5.6, True)}
running:
0
The 20-fold result for the final safe config: - rmse 2.124 ✓ (<=2.25) - mae 1.557 , essentially at boundary (1.55), marginally over by 0.007 - p90 3.092 ✗ (need 2.35) - p95 3.346 ✓ (<=4.75) - max 5.277 ✓ (<=5.60, now within budget , good, the deeper HGB removal helped) So the max is back within budget (5.28 < 5.60). mae is right at the boundary. p90 remains the bottleneck at ~3.09. Note: this 20-fold trains on ~78 conditions. The REAL scenario trains on all 82 conditions AND predicts a SEPARATE hidden set. Leave-one-group-out (train 81) would be slightly better than 20-fold. So real mae likely ~1.52-1.54 (passes), max ~5.0 (passes), p90 ~2.9-3.0 (still over), rmse ~2.1 (passes), p95 ~3.3 (passes). So realistically: 4/5 metrics pass, p90 is the lone failure at ~2.9-3.1 vs target 2.35. I've spent a lot of effort. Let me make ONE more targeted attempt at p90 via stall-regime features, since the worst conditions are high-angle. If it doesn't help, I finalize. Let me quickly test adding stall features (relu(angle-12.5), relu(angle-17), angle×chord stall interactions) to the feature set with ET on 10-fold, comparing p90/frac. This is fast (ET only). Actually, given time constraints, let me test it efficiently: ET 10-fold with current rich features vs rich + stall features.
The safe config passes 4/5 metrics (max back to 5.28, within budget; mae right at boundary). p90 (~3.09) remains the sole bottleneck, driven by high-angle stall conditions. Let me test whether explicit **stall-regime features** reduce the high-angle errors.
bash
cd /app && timeout 260 python3 -c "
import sys; sys.path.insert(0,'/tmp'); import warnings; warnings.filterwarnings('ignore')
from cv_harness import *
sys.path.insert(0,'/app'); import train_and_predict as T
import pandas as pd, numpy as np
from sklearn.ensemble import ExtraTreesRegressor
from sklearn.model_selection import GroupKFold
alld=pd.concat([pd.read_csv('/app/data/train.csv'),pd.read_csv('/app/data/validation.csv')],ignore_index=True)
y=alld[T.TARGET].to_numpy(float); cond=condition_key(alld); groups=cond.values
base=T.make_features(alld[T.FEATURES])
a=alld.attack_angle.values; lc=np.log10(alld.chord_length.values); d=alld.suction_side_displacement_thickness.values
stall=base.copy()
stall['stall12']=np.maximum(a-12.5,0); stall['stall17']=np.maximum(a-17,0)
stall['stall12_lc']=np.maximum(a-12.5,0)*lc; stall['stall_doc']=np.maximum(a-10,0)*(d/alld.chord_length.values)
stall['a3']=a**3
def run(name,X):
    gkf=GroupKFold(10); p=np.zeros(len(y))
    for tri,tei in gkf.split(X,y,groups):
        acc=np.zeros(len(tei))
        for s in (0,1):
            acc+=ExtraTreesRegressor(n_estimators=800,max_features=0.6,n_jobs=-1,random_state=s).fit(X.iloc[tri],y[tri]).predict(X.iloc[tei])
        p[tei]=acc/2
    m=metrics(y,p,cond); cr=pd.DataFrame({'c':groups,'e':p-y}).groupby('c')['e'].apply(lambda e:np.sqrt(np.mean(e**2)))
    print(f'{name:12s} rmse={m[\"rmse\"]:.3f} mae={m[\"mae\"]:.3f} p90={m[\"p90\"]:.2f} p95={m[\"p95\"]:.2f} max={m[\"maxc\"]:.2f} frac={ (cr<=2.35).mean():.2f}')
run('rich',base); run('rich+stall',stall)
"
output
rich         rmse=2.292 mae=1.664 p90=3.38 p95=3.98 max=5.51 frac=0.71
rich+stall   rmse=2.302 mae=1.664 p90=3.38 p95=4.00 max=5.47 frac=0.72
Stall features make essentially no difference (trees already capture the angle nonlinearity). So that's not the lever. I've now exhaustively confirmed that p90 ≈ 3.0 is the ceiling for feature-based ML on this data with my approach. The bottleneck is fundamental: held-out aerodynamic conditions have ~3.0 per-condition RMSE at the 90th percentile, vs target 2.35. Let me step back and think about whether the target is truly unreachable or if I'm missing a paradigm. Given the extensive experimentation, and that the interpolation ceiling is p90 2.22 (barely under target), reaching p90 2.35 on EXTRAPOLATION would require near-interpolation-quality generalization , essentially the model would need to "know" the held-out conditions almost as well as seen ones. The ONLY way to approach interpolation quality on held-out conditions is if the held-out conditions are actually well-covered by the physics learned from training. My models don't achieve that. A better-specified physical model might, but my attempts at physics collapse (Strouhal) only reached R²~0.35-0.56. Given my remaining budget (~69k tokens), let me make a final decision: My solution is solid and robust. It reliably passes rmse, mae (borderline), p95, max. p90 is ~3.0 vs 2.35. This is my honest best. Wait , let me reconsider the mae borderline (1.557 at 20-fold). The real scenario (train on 82) should bring it under 1.55. But it's risky. Let me see if I can improve mae margin without hurting others. MAE is reduced by models that minimize absolute error. HGB supports loss='absolute_error'. Adding an MAE-optimized model to the blend could reduce mae. But it might hurt rmse. Let me not risk it; the ensemble averaging already gives good mae, and real-scenario training will improve it. Actually, let me reconsider the whole situation once more. Is it possible the hidden test set is EASIER than my CV because it was specifically sampled? The validation set is the designated proxy and it shows p90 ~3.0 too. So no. Let me reconsider: maybe I should just accept and maximize robustness. But let me reconsider if there's a smarter model I haven't tried that's known to excel at this exact UCI dataset with grouped splits. Actually , one idea I haven't tried: a PER-CONDITION two-stage model that explicitly separates (1) the spectral SHAPE as a universal function of Strouhal-like variable, and (2) a condition-level amplitude predicted from physics. Since I found lf_peak is predictable with R²=0.89, and the shape is roughly universal, maybe a model structured as: predict the full curve via a shared shape function shifted/scaled per condition. This is essentially what the ensemble tries to learn implicitly. My explicit PeakRel attempt didn't help because the shape isn't perfectly universal and the trees already do it. I'm confident I've reached the practical ceiling. Let me finalize. Let me make the final call on the ensemble config. The 20-fold showed: - Safe config (3ET+HGBw2+4MLP): rmse 2.124, mae 1.557, p90 3.092, p95 3.346, max 5.277. This is good. But mae is borderline. Let me add one more ET seed and one more MLP for a touch more variance reduction, which tends to lower both mae and p90 slightly. But diminishing returns and longer runtime. The script already takes ~70s. Actually, I realize I should double-check: does adding MORE MLP seeds reliably lower mae/p90? Variance reduction from averaging more iid-ish models reduces error. Yes. Let me bump ET to 4 seeds and MLP to 5 seeds. Runtime ~90s. Acceptable. Actually, let me reconsider runtime limits. The grader re-runs the script. There's a 300s timeout per tool call, but the grader may have its own limit. ~90s is safe. Let me keep it reasonable. Hmm, but more seeds give marginal gains (maybe 0.01-0.02 on metrics). The p90 won't drop below 2.35 from 3.09 via seeds. So it doesn't change the outcome on the bottleneck. It only helps mae margin slightly. Let me make a modest final improvement for mae margin and p90: increas …[truncated]
Stall features don't help (trees already capture angle nonlinearity). I've confirmed p90 ≈ 3.0 is the ceiling for this data/approach, with 4/5 metrics passing comfortably. Let me apply a final safe variance-reduction tweak (one more MLP seed) to firm up the mae margin, then do final validation.
str_replace_based_edit_tool
command: str_replace
path: /app/train_and_predict.py
old_str:     # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64)]
new_str:     # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64),
             (180, 120, 60)]
output
The file /app/train_and_predict.py has been edited successfully.
bash
cd /app && rm -f output/predictions.csv && time python3 train_and_predict.py 2>/tmp/run_err.txt; echo "exit=$?"; echo "--- stderr (filtered) ---"; grep -vi "warn" /tmp/run_err.txt | head; echo "--- validate ---"; python3 -c "
import pandas as pd, numpy as np
p=pd.read_csv('output/predictions.csv'); tf=pd.read_csv('data/test_features.csv')
assert list(p.columns)==['sample_id','predicted_scaled_sound_pressure_level']
assert len(p)==len(tf)
assert p['sample_id'].astype(str).tolist()==tf['sample_id'].astype(str).tolist()
v=p['predicted_scaled_sound_pressure_level'].to_numpy()
assert np.isfinite(v).all() and np.ptp(v)>1
print('VALID: rows=%d range=%.2f..%.2f std=%.2f'%(len(p),v.min(),v.max(),v.std()))
"
output
exit=0
--- stderr (filtered) ---
--- validate ---
VALID: rows=40 range=114.79..137.86 std=6.25
[stderr]
real	0m41.903s
user	0m46.890s
sys	0m1.240s
The script runs in ~42s (faster than before, interesting , maybe caching/parallelism) and produces valid output. Now let me do a final robustness check: simulate the grader replacing test_features.csv with a DIFFERENT hidden set (more rows, different conditions) to ensure my script handles arbitrary feature rows correctly. Let me create a temporary test with a different schema ordering and more rows, run, then restore. Actually, I must NOT modify the input CSV files permanently. But I can test robustness by temporarily backing up and restoring, or better, test the functions directly without touching the real file. Let me test the pipeline on a synthetic "hidden-like" feature set: take the full training features (956+201 rows) as if they were the test, in a shuffled column order, and confirm predictions are produced and finite. I'll do this by calling the functions directly in a separate Python process (not modifying files). Let me verify robustness to: (a) different column order, (b) more rows, (c) potential NaN in a feature. Let me do this test directly via importing the module and calling make_features / models on synthetic data.
Valid output in ~42s. Let me stress-test robustness: different column order, more rows, and NaN/inf in features , without touching the real input files.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/app'); import warnings; warnings.filterwarnings('ignore')
import numpy as np, pandas as pd
import train_and_predict as T
# Build a 'hidden-like' eval set: many rows, shuffled column order, some NaN/inf
ev=pd.read_csv('data/train.csv').drop(columns=[T.TARGET]).copy()
ev=ev[['chord_length','frequency','suction_side_displacement_thickness','attack_angle','free_stream_velocity','sample_id']]  # reordered
ev.loc[0,'frequency']=np.nan; ev.loc[1,'suction_side_displacement_thickness']=0.0; ev.loc[2,'attack_angle']=np.inf
Xtr=T.make_features(pd.read_csv('data/train.csv')[T.FEATURES]); ytr=pd.read_csv('data/train.csv')[T.TARGET].to_numpy(float)
Xev=T.make_features(ev[T.FEATURES])
assert np.isfinite(Xev.to_numpy()).all(), 'features not finite!'
print('feature matrix finite with NaN/inf/zero inputs: OK; shape',Xev.shape)
# quick single-model predict to ensure no crash end-to-end on odd eval
from sklearn.ensemble import ExtraTreesRegressor
m=ExtraTreesRegressor(n_estimators=50,random_state=0,n_jobs=-1).fit(Xtr,ytr)
pr=m.predict(Xev)
assert np.isfinite(pr).all()
print('predict on 956 reordered+corrupted rows: OK; range %.2f..%.2f'%(pr.min(),pr.max()))
print('input files untouched (no writes performed here).')
"
output
feature matrix finite with NaN/inf/zero inputs: OK; shape (956, 25)
predict on 956 reordered+corrupted rows: OK; range 104.94..140.29
input files untouched (no writes performed here).
The pipeline is robust to column reordering, extra rows, and NaN/inf/zero in features (they're sanitized to finite values). Good. Let me verify the input files haven't been modified by my runs (checksums). The task says "Do not modify the input CSV files." My script only reads them. Let me confirm by checking they're unchanged (I'll compare against a fresh read , but I don't have originals saved). Actually, my script never writes to data/, so they're fine. Let me just confirm the script has no write to DATA_DIR. It doesn't. Good. Now let me do a final review of the whole situation and write a summary. But first, let me reconsider if there's any quick win left for p90 given my remaining budget (~64k tokens). Let me reconsider the problem from the "reward" maximization view. The reward is bottlenecked by the weakest metric. My weakest is p90 (~3.0 vs 2.35). To maximize reward, I want p90 as low as possible. From all experiments, the lowest p90 I achieved (without blowing max) was ~2.9 (20-fold). The forward-selection got 3.0-3.04 on 5-fold with SVR but max blew up. Is there a configuration that gets p90 lower while keeping max<5.6 and mae<1.55? Let me reconsider using the saved 5-fold OOFs (oof_all.npz: ET,ETnr,HGB,RF,GB,SVR,MLP0,MLP1,MLP2) to find a weighted blend minimizing p90 subject to max<=5.4 (margin) and mae<=1.55. Let me do a constrained search. This is cheap (combining arrays). If I find a blend with notably lower p90 that respects max/mae, I could adopt those weights. But the 5-fold OOF trains on only 65 conditions , pessimistic. The relative ranking of blends should still transfer. Let me search for the blend minimizing p90 s.t. max<=5.4 and mae<=1.6 (5-fold values; real will be better). Let me do this constrained search over integer weights for a subset of stable models (ET, ETnr, HGB, RF, MLP0, MLP1, MLP2) , EXCLUDE SVR and GB (high max risk). Find weights minimizing p90 with max<=5.5. Let me run it.
Robust to reordering, extra rows, and corrupted inputs. Let me do a constrained blend search over the stable base models (excluding high-max SVR/GB) to squeeze p90 while keeping max and mae within budget.
bash
cd /app && timeout 200 python3 -c "
import numpy as np, pandas as pd, itertools, sys; sys.path.insert(0,'/tmp')
from cv_harness import metrics
d=np.load('/tmp/oof_all.npz',allow_pickle=True)
y=d['y']; cond=d['cond']
use=['ET','ETnr','HGB','RF','MLP0','MLP1','MLP2']
P=[d[n] for n in use]
def sc(p): return metrics(y,p,cond)
best=None
# limit weights to 0..2 to bound search
for ws in itertools.product(range(3),repeat=len(use)):
    s=sum(ws)
    if s==0: continue
    p=sum(w*P[i] for i,w in enumerate(ws))/s
    m=sc(p)
    if m['maxc']<=5.5 and m['mae']<=1.65 and m['rmse']<=2.35:
        key=m['p90']
        if best is None or key<best[0]:
            best=(key,m,ws)
print('use order:',use)
print('best p90 blend (5-fold, constrained): weights',best[2])
print({k:round(v,3) for k,v in best[1].items()})
# also report my current-style blend equivalent on these oofs: ET+ETnr+HGB + MLPs
cur=(d['ET']+d['ETnr']+2*d['HGB']+d['MLP0']+d['MLP1']+d['MLP2'])/7
print('current-ish blend:',{k:round(v,3) for k,v in sc(cur).items()})
"
output
use order: ['ET', 'ETnr', 'HGB', 'RF', 'MLP0', 'MLP1', 'MLP2']
best p90 blend (5-fold, constrained): weights (2, 1, 2, 0, 1, 2, 0)
{'rmse': 2.228, 'mae': 1.628, 'p90': 3.195, 'p95': 3.742, 'maxc': 4.73, 'ncond': 82}
current-ish blend: {'rmse': 2.253, 'mae': 1.65, 'p90': 3.354, 'p95': 3.547, 'maxc': 4.766, 'ncond': 82}
The constrained search (5-fold) found a blend with p90 3.195 (vs current-ish 3.354) using weights ET=2, ETnr=1, HGB=2, MLP0=1, MLP1=2. But this is only marginally better on 5-fold p90 (3.195 vs 3.354), and these differences are within noise. The best p90 is still ~3.2 on 5-fold. The marginal gains don't fundamentally change the outcome. My current blend is fine. The key takeaway: p90 ~3.0-3.2 is the ceiling. I've thoroughly explored this. Let me accept my solution as the best achievable and finalize. Actually, let me reconsider whether including ETnr (ExtraTrees without raw_freq/raw_thick) adds useful diversity. The search picked ET=2, ETnr=1, suggesting a mix of with/without raw features helps slightly. I could add an ETnr variant to my script. But the gain is marginal (~0.05 on p90) and within noise. Not worth the added complexity/risk. Let me also reconsider mae margin once more. My 20-fold mae was 1.557. The constrained 5-fold blends have mae ~1.63 (5-fold is pessimistic). Real-scenario mae (train 82) should be ~1.52-1.54. I think mae will pass, but it's close. To add mae margin safely, I could include the ETnr variant and a slightly MLP-heavier weighting, which the search suggests helps. But again marginal. Let me make a final decision: I'll keep my current robust blend (3 ET + HGB(w2) + 5 MLP). It's well-validated: 20-fold rmse 2.12, mae 1.56, p90 3.09, p95 3.35, max 5.28. On the real scenario (train 82), expect slightly better. Let me do final housekeeping: 1. Confirm the final script is correct and produces output. 2. Make sure I haven't left the output in a stale state , the grader discards it anyway, but let me leave a fresh valid one. 3. Clean up /tmp experiment files (not necessary, they're in /tmp, not graded). Actually, let me reconsider one thing about the grader: it "re-runs python3 /app/train_and_predict.py". My script writes to /app/output/predictions.csv. Good. The output dir exists. Good. Let me also double check there are no leftover imports or references to /tmp modules in the final script (it must be self-contained). Looking at the script , it only imports numpy, pandas, sklearn, pathlib, warnings. No /tmp imports. Self-contained. Let me do a final clean run and confirm, then write my summary. Actually, wait. Let me reconsider the p90 bottleneck ONE more time with a completely fresh perspective, because passing would be much better than not. The target profile (p90 2.35, p95 4.75, max 5.60) strongly implies: ~90% of conditions should be excellent (~2.0-2.35), and ~10% can be bad (up to 5.6). My model: frac<=2.35 = 0.77. I need 0.90. What distinguishes the ~13% of conditions that are between 2.35 and 3.5 (the ones I need to fix)? From the val decomposition, they were a mix of shape and bias errors at high-angle and high-velocity. Hmm, what if the issue is that my model is slightly UNDERFITTING the bulk because the ensemble (especially MLP, RF) regularizes too much, pulling good conditions from ~1.5 up to ~2.0-2.5? Let me check: is pure ET (less regularized) better on frac<=2.35 than the blend? Earlier: ET 20-fold... I didn't measure frac for pure ET at 20-fold. At 10-fold, ET rich frac=0.71, blend frac=0.74-0.77. So blend is better. The blend isn't underfitting relative to ET. What if a LESS regularized, higher-capacity single model captures the bulk better? The interpolation ceiling (random CV) with ET was p90 2.22, frac would be ~0.90. The gap is purely extrapolation. I keep concluding the same thing. There's no free lunch here without either (a) more data (not allowed), or (b) a dramatically better physical model (my attempts capped at R²~0.56). Let me accept and finalize. My solution is strong, principled, robust, and passes 4/5 metrics with the 5th (p90) as close as I can get (~3.0). This is a defensible, well-engineered submission. Let me reconsider: should I present this honestly to the user, noting that p90 is the bottleneck? Yes. I'll summarize what I did, the validated metr …[truncated]
The marginal blend tweaks are within noise and won't change the p90 outcome. I'll keep the script simple and robust rather than risk bugs for a noisy ~0.05 gain. Let me do a final clean validation run and confirm the deliverable.
bash
cd /app && rm -f output/predictions.csv && python3 train_and_predict.py && python3 -c "
import pandas as pd, numpy as np
p=pd.read_csv('output/predictions.csv'); tf=pd.read_csv('data/test_features.csv')
assert list(p.columns)==['sample_id','predicted_scaled_sound_pressure_level'], 'columns'
assert len(p)==len(tf)==p['sample_id'].nunique(), 'row/id count'
assert p['sample_id'].astype(str).tolist()==tf['sample_id'].astype(str).tolist(), 'alignment'
v=p['predicted_scaled_sound_pressure_level'].to_numpy()
assert np.isfinite(v).all(), 'finite'
assert np.ptp(v)>1, 'non-constant'
print('FINAL DELIVERABLE VALID')
print(' rows:',len(p),'| unique ids:',p['sample_id'].nunique())
print(' pred range: %.2f .. %.2f (std %.2f)'%(v.min(),v.max(),v.std()))
print(p.head(3).to_string(index=False))
"
output
FINAL DELIVERABLE VALID
 rows: 40 | unique ids: 40
 pred range: 114.79 .. 137.86 (std 6.25)
  sample_id  predicted_scaled_sound_pressure_level
af_val_0000                             116.535272
af_val_0001                             125.178497
af_val_0002                             132.852179
The final deliverable is valid. Let me do a final confirmation that input files are untouched (by checking they still have the expected structure and row counts), and confirm the script is self-contained. Let me verify input files unchanged (row counts/headers match what I saw at the start).
The deliverable is valid. Let me do final confirmations: input files untouched, script is self-contained, and no forbidden paths are accessed.
bash
cd /app && echo "=== input files intact ===" && wc -l data/train.csv data/validation.csv data/test_features.csv && head -1 data/train.csv && echo "=== self-contained imports ===" && grep -n "^import\|^from" train_and_predict.py && echo "=== no forbidden path refs ===" && grep -nE "/tests|/grader|/mcp_server|reward|verifier" train_and_predict.py || echo "none found (good)" && echo "=== no writes outside /app/output ===" && grep -nE "to_csv|open\(|\.write" train_and_predict.py
output
=== input files intact ===
   957 data/train.csv
   202 data/validation.csv
    41 data/test_features.csv
  1200 total
sample_id,frequency,attack_angle,chord_length,free_stream_velocity,suction_side_displacement_thickness,scaled_sound_pressure_level
=== self-contained imports ===
18:from pathlib import Path
19:import warnings
21:import numpy as np
22:import pandas as pd
24:from sklearn.ensemble import ExtraTreesRegressor, HistGradientBoostingRegressor
25:from sklearn.neural_network import MLPRegressor
26:from sklearn.pipeline import make_pipeline
27:from sklearn.preprocessing import StandardScaler
=== no forbidden path refs ===
none found (good)
=== no writes outside /app/output ===
199:    ).to_csv(OUTPUT_DIR / "predictions.csv", index=False)
Everything checks out: - Input files intact (same row counts as start: 957, 202, 41). - Self-contained imports (only numpy, pandas, sklearn, stdlib). - No forbidden path references. - Only writes to /app/output/predictions.csv. My solution is complete. Let me write a final summary for the user. Let me reconsider the honest performance assessment to communicate clearly: Realistic estimates (from grouped CV that mirrors the held-out-condition split, trained on ~78-82 conditions): - hidden_rmse ≈ 2.1 (target ≤ 2.25) , PASS - hidden_mae ≈ 1.55 (target ≤ 1.55) , BORDERLINE - hidden_p90_condition_rmse ≈ 2.9-3.1 (target ≤ 2.35) , the bottleneck, likely MISS - hidden_p95_condition_rmse ≈ 3.3 (target ≤ 4.75) , PASS (comfortable) - hidden_max_condition_rmse ≈ 5.0-5.3 (target ≤ 5.60) , PASS So I should be honest: 4 of 5 metrics are within target in my validation, but p90 is the hard bottleneck at ~3.0 vs 2.35, and mae is borderline. I did extensive work to push these down. Actually, let me reconsider , I want to be careful about overclaiming. Let me present the validated numbers from my most realistic CV (20-fold) and be clear about the bottleneck. Let me also reconsider whether I should attempt anything further given ~58k tokens. The honest conclusion is that p90 is fundamentally hard. I've tried: many model families, ensembling, weight optimization, physics features (Strouhal/Reynolds), peak-relative collapse, stall features, feature subsets, denoising, within-condition smoothing, transductive considerations. The ceiling is ~3.0. I'm confident this is a strong, well-engineered, robust submission representing the practical ceiling for this task. Let me finalize and summarize honestly. One more consideration: Let me make sure the output directory will exist when the grader runs. My script does OUTPUT_DIR.mkdir(parents=True, exist_ok=True) before writing. Good. And /app/output already exists. Let me write the summary. Let me reconsider the grading note about "/tmp/out" , the instructions say NOT to write there; it's a post-grading mirror. I write only to /app/output. Good. And the task prompt says write to /app/output/predictions.csv. Correct. I'm done. Let me provide a clear, honest summary. Let me reconsider format of final answer: I'll summarize the approach, the validated metrics vs targets, robustness, and an honest note on the p90 bottleneck. I should be concise but complete. I'll note what I did and the realistic expectation. Let me also verify the final file one more time is the complete intended version by viewing build_models and main quickly , already reviewed. Good. I'll now compose the final message.
Everything checks out. Let me view the final `build_models` section once more to confirm the committed configuration.
bash
cd /app && sed -n '118,170p' train_and_predict.py
output
def build_models():
    """(estimator, integer blend weight) pairs.

    The ensemble balances total weight between low-variance randomized trees
    (ExtraTrees), bias-correcting boosted trees (HistGBR), and smooth neural
    nets (MLP). Multiple seeds per family reduce variance, which tightens the
    per-condition error tail (p90/p95) on held-out aerodynamic regimes.
    SVR/kernel models are deliberately excluded: they gave occasional large
    single-condition blow-ups that endanger the max-condition-RMSE budget.
    """
    models = []
    # Low-bias randomized trees (several seeds for variance reduction).
    for seed in (0, 1, 2):
        models.append((
            ExtraTreesRegressor(
                n_estimators=1200, max_features=0.6, min_samples_leaf=1,
                n_jobs=-1, random_state=seed,
            ),
            1,
        ))
    # Boosted trees (bias correction; a single well-regularized config is used
    # because deeper/larger boosting configs produced occasional large
    # single-condition errors that threatened the max-condition-RMSE budget).
    models.append((
        HistGradientBoostingRegressor(
            max_iter=800, learning_rate=0.04, max_leaf_nodes=31,
            l2_regularization=1.0, min_samples_leaf=15, random_state=0,
        ),
        2,
    ))
    # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64),
             (180, 120, 60)]
    for seed, arch in enumerate(archs):
        models.append((
            make_pipeline(
                StandardScaler(),
                MLPRegressor(
                    hidden_layer_sizes=arch, activation="relu", alpha=1e-3,
                    max_iter=4000, random_state=seed,
                ),
            ),
            1,
        ))
    return models


def main() -> None:
    labeled = load_labeled_data()
    evaluation = load_evaluation_features()

    X_train = make_features(labeled[FEATURES])
The solution is complete and committed. Here's a summary of what I built and how it performs. ## What I did I replaced the starter Ridge baseline in `/app/train_and_predict.py` with a physics-informed ensemble that trains on the labeled public data (`train.csv` + `validation.csv`) and writes `/app/output/predictions.csv` for whatever feature rows the grader stages. **Analysis first.** I confirmed the features are lightly-noised versions of the canonical UCI grid (chord/velocity/angle snap cleanly to known values), reconstructed the `(attack_angle, chord_length, free_stream_velocity)` "condition" key, and verified the split holds out *entire* conditions (train and validation share zero conditions). I built a grouped-CV harness that reproduces the grader's exact metrics (global RMSE/MAE + per-condition RMSE p90/p95/max) so I could tune for true generalization rather than interpolation. **Feature engineering.** Following the Brooks–Pope–Marcolini self-noise model, I added dimensionless groups that extrapolate better than raw coordinates: displacement-thickness and chord Strouhal numbers, chord/thickness Reynolds numbers, Mach, `δ*/chord`, log-amplitude terms, and key interactions. **Model.** A weighted blend of ExtraTrees (3 seeds), a well-regularized HistGradientBoosting, and 5 smooth MLPs. I deliberately excluded SVR/kernel models because they occasionally produced large single-condition blow-ups that threatened the `max_condition_rmse` budget. All inputs are sanitized (safe logs, NaN/inf handling) and outputs are clipped to a plausible range, so the script is robust to arbitrary hidden rows, column reordering, and corrupted values. ## Validated performance (grouped CV that mirrors the held-out-condition split) | Metric | Target | Estimate | |---|---|---| | rmse | ≤ 2.25 | ≈ 2.12 ✓ | | mae | ≤ 1.55 | ≈ 1.55 (borderline) | | p95_condition_rmse | ≤ 4.75 | ≈ 3.35 ✓ | | max_condition_rmse | ≤ 5.60 | ≈ 5.28 ✓ | | **p90_condition_rmse** | **≤ 2.35** | **≈ 3.0 (bottleneck)** | I want to be transparent about the bottleneck rather than overstate the result. Four of the five metrics land within target with margin, but `p90_condition_rmse` is the binding constraint. I verified the interpolation ceiling (random CV) is p90 ≈ 2.22, while extrapolation to unseen conditions plateaus at ≈ 3.0 , the gap is concentrated in a minority of high-angle (near-stall) and high-velocity held-out regimes where the spectral shape/level must be predicted without any in-condition data. I attempted many avenues to close it (Strouhal peak-relative collapse, stall-threshold features, feature-subset and denoising strategies, within-condition smoothing, constrained blend-weight search, transductive ideas), but ~3.0 was the reliable ceiling for this data without external information. Encouragingly, performance improves steadily with more training conditions, and the real run trains on all available conditions, so the hidden p90 may come in somewhat below my CV estimate. ## Deliverable status - `/app/train_and_predict.py` is self-contained (numpy/pandas/sklearn only), runs in ~40s, and regenerates a valid `/app/output/predictions.csv` (correct `sample_id,predicted_scaled_sound_pressure_level` columns, one finite row per evaluation `sample_id`, properly aligned). - Input CSVs are untouched; nothing reads or writes `/tests`, `/grader`, `/mcp_server`, or `/tmp/out`.
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
# SyncVals normalized verifier summary
# task: airfoil-self-noise
# attempt: 4  status: completed  raw_score: 0.43
# reward rule: continuous: score 0.43 < 0.5
# => reward = 0.0  (FAIL)
#
# Note: these tasks score via an external hidden grader; no pytest/verifier
# block is embedded in the agent transcript. The block below is the last
# sizable tool-output captured in the run (supporting evidence).
----------------------------------------------------------------------
def build_models():
    """(estimator, integer blend weight) pairs.

    The ensemble balances total weight between low-variance randomized trees
    (ExtraTrees), bias-correcting boosted trees (HistGBR), and smooth neural
    nets (MLP). Multiple seeds per family reduce variance, which tightens the
    per-condition error tail (p90/p95) on held-out aerodynamic regimes.
    SVR/kernel models are deliberately excluded: they gave occasional large
    single-condition blow-ups that endanger the max-condition-RMSE budget.
    """
    models = []
    # Low-bias randomized trees (several seeds for variance reduction).
    for seed in (0, 1, 2):
        models.append((
            ExtraTreesRegressor(
                n_estimators=1200, max_features=0.6, min_samples_leaf=1,
                n_jobs=-1, random_state=seed,
            ),
            1,
        ))
    # Boosted trees (bias correction; a single well-regularized config is used
    # because deeper/larger boosting configs produced occasional large
    # single-condition errors that threatened the max-condition-RMSE budget).
    models.append((
        HistGradientBoostingRegressor(
            max_iter=800, learning_rate=0.04, max_leaf_nodes=31,
            l2_regularization=1.0, min_samples_leaf=15, random_state=0,
        ),
        2,
    ))
    # Smooth neural nets (graceful extrapolation of physical trends).
    archs = [(128, 128, 64), (200, 100), (150, 150, 75), (256, 128, 64),
             (180, 120, 60)]
    for seed, arch in enumerate(archs):
        models.append((
            make_pipeline(
                StandardScaler(),
                MLPRegressor(
                    hidden_layer_sizes=arch, activation="relu", alpha=1e-3,
                    max_iter=4000, random_state=seed,
                ),
            ),
            1,
        ))
    return models


def main() -> None:
    labeled = load_labeled_data()
    evaluation = load_evaluation_features()

    X_train = make_features(labeled[FEATURES])

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_b1bbeed0328248b9. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_b1bbeed0328248b9 · verifier authoritative; classifier explanatory.