SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

airfrans-high-reynolds-drag-extrapolation

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.
SubtypeTimeout / Incomplete Execution
EvidenceThe agent's trajectory shows extensive experimental work (runs 1-6) validating that MAE loss + SWA + physics velocity augmentation achieves mean_nrmse ~0.114-0.147 in extrapolation tests, which would score ~0.20+ reward. However, the final checkpoint saved to /app/outputs/model.pt scores 0.0 reward (mean_nrmse far above baseline). The trajectory shows the agent launching final_train.py at step 198 ('started pid 1253') but the log file ends immediately after. The checkpoint exists with correct structure (all 5 keys present per verifier output), but apparently contains poorly-trained weights, suggesting the training either didn't complete properly, completed too quickly with poor initialization, or was interrupted before convergence. The agent's pseudo-extrapolation validation clearly demonstrated their methodology (e.g., run5: 'mae_swa | XHARD mean=0.1387' vs 'mse_swa | XHARD mean=0.1472') should yield passing performance.
Root causeThe agent conducted thorough experimental validation showing their final configuration would achieve ~0.114-0.147 NRMSE (passing territory), but appears to have run out of time or failed to properly execute the final training. The checkpoint exists but contains untrained or poorly-trained weights, resulting in 0.0 reward instead of the predicted ~0.20+ reward their methodology should have achieved.
RecommendationN/A - task is fine. The task specification is precise (extrapolation challenge with clear data splits, fixed PointNet architecture, normalized metric definitions). The agent's failure stems from execution/time management, not task ambiguity. The physics-based approach (velocity augmentation with Reynolds scaling of drag) and MAE loss were sound strategies that were empirically validated to improve extrapolation performance."
Trajectory
Tool-by-tool agent trajectory
335 tool calls · 3 tool types · 335 steps
Aerodynamicists increasingly lean on learned surrogates to skip expensive CFD runs, and one of the most useful things such a surrogate can do is read an airfoil's surface state and tell you the integrated forces on it. That is the job here. For every simulated case you are handed the airfoil's surface as a cloud of 256 points. Each point carries four numbers: its x and y position along the chord-normalized profile, and the two free-stream conditions for the case: the inlet velocity and the angle of attack, repeated on every point so the network always has them at hand. From that surface cloud you must predict the case's two force coefficients, drag and lift. The cases come from a campaign of RANS simulations spanning many airfoil shapes and flow conditions. Your training and validation splits cover part of that campaign; the cases you are ultimately scored on are sampled from the higher-speed, higher-Reynolds end of it, so the evaluation reaches beyond the inlet velocities present in your training data. Plan for that extrapolation rather than assuming the scored cases look just like training. ## Files - `/app/data/train/split.pt` and `/app/data/val/split.pt`: each is a dict with `points` (a `[N, 256, 4]` float32 tensor) and `targets` (a `[N, 2]` float32 tensor of `[C_D, C_L]`). Load them with `torch.load(path, weights_only=True)`. - `/app/data/public_test/split.pt`: a dict with `points` only (no targets), handy for checking that your inference pipeline runs end to end. - `/app/task_config.json`: point count, input dimension, target count, the architecture sizes, and the default training settings. - `/app/feature_schema.json`: what each input channel and target means. - `/app/candidate_model.py`: the fixed PointNet you must train. Leave the architecture alone; your checkpoint has to load straight back into it. - `/app/dataset.py`: helpers for loading a split and standardizing it. - `/app/train.py`: a small starter loop. Treat it as a starting point, not a ceiling. ## The model The architecture is fixed: a shared per-point MLP (`4 -> 64 -> 128 -> 256`), a global max-pool over the 256 points, and a head (`256 -> 128 -> 64 -> 2`). You are free to change everything about how you train (the loss, the normalization, augmentation, the schedule, model selection) but not the network itself. ## What to hand back Write your trained checkpoint to `/app/outputs/model.pt` as a dict containing: - `state_dict`: your model's `state_dict()`. - `feat_mean`, `feat_std`: length-4 tensors that standardize the point features before the forward pass. - `targ_mean`, `targ_std`: length-2 tensors that map the model's outputs back into physical coefficient units. All four normalization tensors must be present. Your weights are loaded back into this exact architecture and run on the scored cases, so the checkpoint has to match it and the de-standardized `[C_D, C_L]` predictions are read straight from the model output. ## What you are optimizing You are predicting the two force coefficients `[C_D, C_L]` for each case, and the quality of your predictions is measured by how close they are to the true coefficients. Lower error is better, and both the drag and the lift coefficient matter, so aim to do well on both rather than trading one off against the other.
Let me start by exploring the environment to understand what I'm working with. Let me look at the files provided.
I'll start by exploring the environment to understand the task, data, and provided code.
bash
cd /app && ls -la && echo "---- CONFIG ----" && cat task_config.json && echo "---- SCHEMA ----" && cat feature_schema.json
output
total 21
drwxrws---  3 h2tagent h2tagent 4096 Jun 19 21:15 .
drwxr-xr-x 26 root     root     4096 Jun 19 21:26 ..
-rw-rw----  1 h2tagent h2tagent 2093 Jun 19 21:13 candidate_model.py
drwxrws---  5 h2tagent h2tagent 4096 Jun 19 21:13 data
-rw-rw----  1 h2tagent h2tagent 1411 Jun 19 21:13 dataset.py
-rw-rw----  1 h2tagent h2tagent  723 Jun 19 21:13 feature_schema.json
-rw-rw----  1 h2tagent h2tagent  547 Jun 19 21:13 task_config.json
-rw-rw----  1 h2tagent h2tagent 2900 Jun 19 21:13 train.py
---- CONFIG ----
{
  "task_id": "airfrans-high-reynolds-drag-extrapolation",
  "dataset_name": "airfrans-original-subset",
  "n_points": 256,
  "in_dim": 4,
  "n_targets": 2,
  "chord_axis": 1,
  "aoa_index": 3,
  "lift_index": 1,
  "velocity_index": 2,
  "seed": 20260518,
  "model": {
    "point_mlp": [64, 128, 256],
    "head": [128, 64]
  },
  "training": {
    "epochs": 40,
    "batch_size": 32,
    "lr": 0.001,
    "weight_decay": 0.0001
  },
  "evaluation": {
    "primary_metric": "mean_nrmse",
    "secondary_metrics": ["worst_nrmse", "cd_nmae"]
  }
}
---- SCHEMA ----
{
  "version": "airfrans-original-subset-v1",
  "point_cloud": {
    "n_points": 256,
    "in_dim": 4,
    "channels": [
      {"name": "x", "description": "Airfoil-surface node x coordinate (chord-normalized)."},
      {"name": "y", "description": "Airfoil-surface node y coordinate (chord-normalized)."},
      {"name": "inlet_velocity", "description": "Free-stream inlet velocity magnitude in m/s, broadcast to every point."},
      {"name": "angle_of_attack", "description": "Free-stream angle of attack in radians, broadcast to every point."}
    ]
  },
  "targets": [
    {"name": "C_D", "description": "Drag coefficient of the airfoil."},
    {"name": "C_L", "description": "Lift coefficient of the airfoil."}
  ]
}
Let me look at the model, dataset, and train files.
Let me examine the model architecture, dataset helpers, and training starter code.
bash
cd /app && echo "==== candidate_model.py ====" && cat candidate_model.py && echo "==== dataset.py ====" && cat dataset.py && echo "==== train.py ====" && cat train.py
output
==== candidate_model.py ====
"""PointNet regressor for the airfoil force-coefficient task.

Your trained weights are loaded back into the exact module returned by
build_model and a forward pass is run on held-out point clouds, so the
architecture is part of the task contract. The model maps a surface point cloud
[B, P, in_dim] carrying per-point geometry and broadcast flow conditions to
n_targets coefficients via a shared per-point MLP, global max-pool, and a head.
Output is in standardized target space and is mapped back to physical units
afterward.
"""

from __future__ import annotations

from typing import Mapping

import torch
import torch.nn as nn


class SharedMLP(nn.Module):
    def __init__(self, channels: list[int]) -> None:
        super().__init__()
        layers: list[nn.Module] = []
        for i in range(len(channels) - 1):
            layers += [nn.Conv1d(channels[i], channels[i + 1], 1), nn.BatchNorm1d(channels[i + 1]), nn.GELU()]
        self.net = nn.Sequential(*layers)

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        return self.net(x)


class PointNetRegressor(nn.Module):
    def __init__(self, in_dim: int, point_mlp: list[int], head: list[int], n_targets: int) -> None:
        super().__init__()
        self.n_targets = n_targets
        self.encoder = SharedMLP([in_dim, *point_mlp])
        head_layers: list[nn.Module] = []
        dims = [point_mlp[-1], *head]
        for i in range(len(dims) - 1):
            head_layers += [nn.Linear(dims[i], dims[i + 1]), nn.GELU()]
        head_layers += [nn.Linear(dims[-1], n_targets)]
        self.head = nn.Sequential(*head_layers)

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        x = x.transpose(1, 2)
        feat = self.encoder(x)
        pooled = feat.max(dim=2).values
        return self.head(pooled)


def build_model(config: Mapping) -> PointNetRegressor:
    m = config["model"]
    return PointNetRegressor(
        in_dim=int(config["in_dim"]),
        point_mlp=[int(c) for c in m["point_mlp"]],
        head=[int(c) for c in m["head"]],
        n_targets=int(config["n_targets"]),
    )
==== dataset.py ====
"""Point-cloud dataset utilities for the airfoil force-coefficient task.

On-disk format per split: a single split.pt containing a dict with key points
(tensor [N, P, in_dim], float16 on disk) and, for labeled splits, targets
(tensor [N, n_targets], float32). The public_test split ships points only; the
hidden split ships points and labels separately and only points are exposed to
the model at inference.
"""

from __future__ import annotations

from pathlib import Path

import torch


def load_split(split_dir: str | Path) -> tuple[torch.Tensor, torch.Tensor | None]:
    payload = torch.load(Path(split_dir) / "split.pt", map_location="cpu", weights_only=True)
    targets = payload["targets"].float() if "targets" in payload else None
    return payload["points"].float(), targets


def coord_standardizer(points: torch.Tensor) -> tuple[torch.Tensor, torch.Tensor]:
    flat = points.reshape(-1, points.shape[-1])
    mean = flat.mean(dim=0)
    std = flat.std(dim=0).clamp_min(1e-8)
    return mean, std


def target_standardizer(targets: torch.Tensor) -> tuple[torch.Tensor, torch.Tensor]:
    mean = targets.mean(dim=0)
    std = targets.std(dim=0).clamp_min(1e-8)
    return mean, std


def iter_indices(n: int, batch_size: int, shuffle: bool = True):
    idx = torch.randperm(n) if shuffle else torch.arange(n)
    for start in range(0, n, batch_size):
        yield idx[start : start + batch_size]
==== train.py ====
"""Weak baseline trainer: single global-pool PointNet, plain MSE, short budget.

Standardizes point coordinates and targets, trains the pinned regressor to
predict standardized targets under MSE, and saves the four normalization
tensors alongside the state_dict. No augmentation, no per-target weighting, no
early stopping. Candidates are expected to do better on the held-out regime --
input jitter/rotation augmentation, deep
…[truncated]
Now let me explore the data to understand its characteristics. This is the key to understanding the extrapolation challenge.
Now let me examine the actual data to understand its structure and distributions. This is crucial given the extrapolation challenge mentioned.
bash
cd /app && python3 -c "
import torch
for split in ['train','val','public_test']:
    p = torch.load(f'data/{split}/split.pt', weights_only=True)
    print(f'==== {split} ====')
    print('keys:', list(p.keys()))
    print('points shape/dtype:', p['points'].shape, p['points'].dtype)
    if 'targets' in p:
        print('targets shape/dtype:', p['targets'].shape, p['targets'].dtype)
"
output
==== train ====
keys: ['points', 'targets']
points shape/dtype: torch.Size([630, 256, 4]) torch.float32
targets shape/dtype: torch.Size([630, 2]) torch.float32
==== val ====
keys: ['points', 'targets']
points shape/dtype: torch.Size([80, 256, 4]) torch.float32
targets shape/dtype: torch.Size([80, 2]) torch.float32
==== public_test ====
keys: ['points']
points shape/dtype: torch.Size([100, 256, 4]) torch.float32
bash
cd /app && python3 -c "
import torch
tr = torch.load('data/train/split.pt', weights_only=True)
va = torch.load('data/val/split.pt', weights_only=True)
pt = torch.load('data/public_test/split.pt', weights_only=True)

def stats(name, pts):
    # channels: x, y, inlet_velocity, angle_of_attack
    ch = pts.reshape(-1,4)
    names=['x','y','vel','aoa']
    print(f'--- {name} per-channel (over all points) ---')
    for i,n in enumerate(names):
        c = ch[:,i]
        print(f'  {n:4s}: min={c.min():.4f} max={c.max():.4f} mean={c.mean():.4f} std={c.std():.4f}')

stats('train', tr['points'])
stats('val', va['points'])
stats('public_test', pt['points'])
"
output
--- train per-channel (over all points) ---
  x   : min=-0.0070 max=1.0000 mean=0.3835 std=0.3956
  y   : min=-0.0997 max=0.1627 mean=0.0079 std=0.0335
  vel : min=31.2830 max=74.9240 mean=52.9737 std=12.7859
  aoa : min=-0.0862 max=0.2565 mean=0.0764 std=0.0956
--- val per-channel (over all points) ---
  x   : min=-0.0033 max=1.0000 mean=0.3846 std=0.3959
  y   : min=-0.0939 max=0.1366 mean=0.0078 std=0.0323
  vel : min=31.4680 max=74.1620 mean=54.9773 std=11.3969
  aoa : min=-0.0836 max=0.2512 mean=0.0799 std=0.0947
--- public_test per-channel (over all points) ---
  x   : min=-0.0055 max=1.0000 mean=0.3761 std=0.3946
  y   : min=-0.0961 max=0.1528 mean=0.0088 std=0.0346
  vel : min=75.0300 max=81.5930 mean=78.2086 std=1.9658
  aoa : min=-0.0857 max=0.2582 mean=0.0757 std=0.0961
This is the critical insight. The velocity distribution: - train: vel in [31.28, 74.92], mean 52.97 - val: vel in [31.47, 74.16], mean 54.98 - public_test: vel in [75.03, 81.59], mean 78.21 So the public_test (and presumably the hidden scored set) has velocities that are **entirely above** the training range. Train max is 74.92, and public_test min is 75.03. This is a clear extrapolation in the velocity dimension. The x, y, aoa distributions look similar across splits. Only velocity is shifted to higher values. This is the core challenge. Let me think about the physics here. The task description says: "the cases you are ultimately scored on are sampled from the higher-speed, higher-Reynolds end of it, so the evaluation reaches beyond the inlet velocities present in your training data." So the scored set likely has velocities even higher, or at least in the 75-82 range like public_test. We need the model to extrapolate in velocity. Let me think about the physics of aerodynamic force coefficients. Force coefficients C_D and C_L are *normalized* forces: C_L = L / (0.5 * rho * V^2 * A) C_D = D / (0.5 * rho * V^2 * A) In incompressible flow, the force coefficients are theoretically **independent of velocity** (they depend on Reynolds number and angle of attack and shape). At low Mach, C_L and C_D depend mostly on angle of attack and airfoil shape, and weakly on Reynolds number (which scales with velocity). So actually, the physics tells us: C_L and C_D should be roughly independent of the absolute velocity! They depend on AoA, shape, and Reynolds number (via velocity). Wait but this is AirfRANS. Let me recall AirfRANS dataset. AirfRANS is a dataset of RANS simulations around airfoils (NACA 4 and 5 digit series) at various angles of attack and inlet velocities. The force coefficients (drag C_D and lift C_L) are computed. In AirfRANS, the inlet velocity ranges and angle of attack ranges... The "scarce" task and "full" task and "Reynolds" and "aoa" extrapolation regimes. There's specifically a "Reynolds" regime where training is done on a range of Reynolds and testing on extrapolated Reynolds. The Reynolds number is proportional to inlet velocity (since chord and viscosity fixed). So this matches: the "Reynolds extrapolation" task of AirfRANS. Training Reynolds in some range, test on higher Reynolds. Key physics: For airfoils at a given angle of attack, as Reynolds number increases: - C_D generally *decreases* (skin friction coefficient decreases with Re). - C_L is relatively less sensitive but changes somewhat. So the velocity does matter for the coefficients, but through Reynolds number effects. The key question: how do we best handle the extrapolation? Approach ideas: 1. Feature engineering: Since velocity only enters as a feature, and the network has to extrapolate, we need to make the velocity-dependence learnable in a way that extrapolates well. 2. The most important thing: The model input includes velocity as a raw feature (broadcast). If we standardize it using training mean/std, then at test time velocity values are far outside (z-scores much larger). With BatchNorm and GELU and max-pool, the network might behave unpredictably in extrapolation. Let me think about what determines C_D and C_L physically and whether velocity (within this range) matters much. Actually, let me look at the actual data relationships. Let me compute correlations between velocity, aoa and targets in the training set. Let me first understand: each case has a single velocity and single aoa (broadcast to all 256 points). And x,y describe the airfoil shape. Let me verify velocity and aoa are constant per-case.
The key insight is already visible: **velocity in `public_test` (75.0–81.6) is entirely above the training range (31.3–74.9)**. This is a pure extrapolation in the velocity/Reynolds dimension, while x, y, and AoA distributions overlap. Let me dig deeper into the data relationships.
bash
cd /app && python3 -c "
import torch
tr = torch.load('data/train/split.pt', weights_only=True)
pts, tg = tr['points'], tr['targets']
# verify vel & aoa constant per case
vel = pts[:,:,2]; aoa = pts[:,:,3]
print('vel per-case std max:', vel.std(dim=1).max().item())
print('aoa per-case std max:', aoa.std(dim=1).max().item())
# per-case scalar
v = vel[:,0]; a = aoa[:,0]
cd, cl = tg[:,0], tg[:,1]
print()
print('targets ranges:')
print('  C_D: min=%.5f max=%.5f mean=%.5f std=%.5f' % (cd.min(), cd.max(), cd.mean(), cd.std()))
print('  C_L: min=%.5f max=%.5f mean=%.5f std=%.5f' % (cl.min(), cl.max(), cl.mean(), cl.std()))
print()
def corr(a,b):
    a=a-a.mean(); b=b-b.mean()
    return (a*b).sum()/(a.norm()*b.norm())
print('corr(vel, C_D):', corr(v,cd).item())
print('corr(vel, C_L):', corr(v,cl).item())
print('corr(aoa, C_D):', corr(a,cd).item())
print('corr(aoa, C_L):', corr(a,cl).item())
print('corr(aoa^2, C_D):', corr(a**2,cd).item())
"
output
vel per-case std max: 0.0
aoa per-case std max: 0.0

targets ranges:
  C_D: min=0.00727 max=0.04595 mean=0.01276 std=0.00510
  C_L: min=-0.53363 max=1.85012 mean=0.65962 std=0.57620

corr(vel, C_D): -0.15417733788490295
corr(vel, C_L): -0.02204255387187004
corr(aoa, C_D): 0.7387089133262634
corr(aoa, C_L): 0.9433279633522034
corr(aoa^2, C_D): 0.8596727252006531
So as expected: - aoa strongly correlates with C_L (0.943) and C_D (0.739; C_D correlates even more with aoa^2 at 0.86). - velocity has weak correlation with C_D (-0.154) and near-zero with C_L. This confirms the physics: C_L and C_D are dominated by angle of attack (and shape). Velocity (Reynolds) has a weaker, secondary effect , mainly on C_D (drag decreases slightly with Reynolds / velocity, negative correlation -0.15). So the extrapolation concern: at higher velocity, the model needs to not go crazy. Since velocity has a weak effect, the main risk is that the network latches onto velocity spuriously and extrapolates poorly. Let me think about Reynolds number. Re = V * chord / nu. In AirfRANS, chord = 1 (normalized), and nu (kinematic viscosity of air) ~ 1.56e-5 m^2/s. So Re ranges: - train: V in [31, 75] -> Re in [2.0e6, 4.8e6] - test: V in [75, 82] -> Re in [4.8e6, 5.2e6] Drag coefficient skin friction ~ Re^(-1/5) for turbulent. So as Re increases, C_D decreases slightly. The negative correlation of -0.15 is consistent. Now, the important modeling question. Let me think about how to make this extrapolate well. Key ideas: 1. **Feature transformation for velocity**: The relationship of coefficients to velocity is through Reynolds/physics. If I feed raw velocity (standardized), the network sees z-scores. At test, z-scores are ~2-3 std above mean. The network's learned function of velocity is only fit on the training range and may extrapolate arbitrarily (GELU MLPs can extrapolate linearly-ish but with max-pool and the structure, hard to say). 2. Actually , a crucial realization: Since C_L and C_D depend only weakly on velocity, maybe the best strategy for robustness is to reduce the model's sensitivity to velocity, or to encode velocity in a way that the physically-correct weak dependence is captured but doesn't explode. Let me think about the dominant physical picture: - C_L ≈ f(aoa, shape). Nearly independent of V. - C_D ≈ f(aoa, shape, Re). Weak Re dependence. One robust approach: if the network learns C_L and C_D essentially as functions of aoa and shape, ignoring velocity, it would extrapolate fine in velocity (since velocity barely matters). The danger is overfitting to velocity within the training range. But there's a subtlety: there IS a real Reynolds effect on C_D. At higher Re, drag is lower. If we ignore velocity entirely, we'd predict C_D slightly too high at test. But the effect is weak. Let me quantify the velocity effect on C_D more carefully by controlling for aoa. Let me do a regression. Actually, let me think more carefully. Let me fit some simple models to understand the structure and get a baseline for what's achievable, and importantly to understand how C_D depends on velocity after controlling for aoa and shape. Let me think about the evaluation metric: "mean_nrmse" , normalized RMSE, averaged over the two targets. Secondary: worst_nrmse, cd_nmae. NRMSE is probably RMSE normalized by something (range or std or mean of the true values). Let me think: NRMSE normalized by std or by range or by mean. Given "both drag and lift matter, aim to do well on both rather than trading off", and the metric is mean_nrmse (mean over targets of per-target NRMSE). NRMSE normalizes each target so they're comparable despite C_D ~ 0.01 scale and C_L ~ 0.66 scale. NRMSE is likely RMSE / (max - min) or RMSE / mean or RMSE / std of the true targets. This matters for how I weight the loss. Since I don't know the exact normalization, a safe bet is to optimize each target in a normalized space (e.g., standardized), which handles scale. Actually predicting in standardized target space and minimizing MSE there gives equal weight to each target's standardized error, which aligns with NRMSE-by-std. If NRMSE is normalized by std (of the hidden test targets), then minimizing standardized MSE per target is exactly right. If normalized by range, similar idea. Either way, balancing both targets in standardized space is the …[truncated]
Let me confirm the key findings and check the compute environment.
bash
cd /app && python3 -c "
import torch, sys
print('torch', torch.__version__)
print('cuda available:', torch.cuda.is_available())
if torch.cuda.is_available():
    print('gpu:', torch.cuda.get_device_name(0))
import os; print('cpus:', os.cpu_count())
" && echo "---- velocity histograms ----" && python3 -c "
import torch, numpy as np
for s in ['train','val','public_test']:
    p=torch.load(f'data/{s}/split.pt',weights_only=True)['points']
    v=p[:,0,2].numpy()
    h,edges=np.histogram(v,bins=[30,40,50,60,70,75,80,85])
    print(f'{s:12s}', dict(zip([f'{int(edges[i])}-{int(edges[i+1])}' for i in range(len(h))],h.tolist())))
"
output
torch 2.5.1+cu124
cuda available: False
cpus: 16
---- velocity histograms ----
train        {'30-40': 132, '40-50': 140, '50-60': 141, '60-70': 147, '70-75': 70, '75-80': 0, '80-85': 0}
val          {'30-40': 11, '40-50': 15, '50-60': 23, '60-70': 24, '70-75': 7, '75-80': 0, '80-85': 0}
public_test  {'30-40': 0, '40-50': 0, '50-60': 0, '60-70': 0, '70-75': 0, '75-80': 75, '80-85': 25}
Confirmed: - No GPU, CPU only with 16 cores. The model is small so CPU training is fine. - Train velocity spans 31-75, val 31-75, public_test 75-82. - The gap: training max velocity is ~75, public_test starts at 75. So the test is a clean extrapolation to higher velocities. Now let me understand the physics of C_D vs velocity better. Let me try to isolate the velocity (Reynolds) effect on C_D after controlling for aoa and shape. Let me compute geometric descriptors per airfoil to control for shape, and do a regression. Let me build features: - aoa, aoa^2 - max thickness, camber, etc. from the point cloud - velocity Actually, let me think about whether shapes repeat across velocities. In AirfRANS, the sampling is typically random (shape, aoa, Re) combos, so shapes likely don't repeat exactly. But I can still do a regression controlling for geometry. Let me extract geometric features and regress. But actually, let me take a more direct empirical approach to the core question: "How should I handle velocity to extrapolate best?" I'll build the pseudo-extrapolation split and test strategies. But first, understanding the velocity->C_D relationship helps design augmentation. Let me fit a gradient-boosted model or linear model with geometry features to see the partial dependence on velocity. Let me extract per-case geometric features: - x,y give the airfoil contour (256 points). - thickness: max(y) - min(y) roughly, or better, the max thickness. - The coordinates are chord-normalized with x in [0,1]. Let me compute simple shape descriptors: max y, min y, thickness (max-min), x-location of max thickness, trailing edge behavior, etc. Also the points include the angle of attack already baked into... wait, no. Let me check: are the x,y coordinates rotated by angle of attack, or are they the raw airfoil shape? In AirfRANS, the geometry is the airfoil in its own frame (chord along x), and aoa is separate. Let me check if the point cloud is rotated. Since aoa is given as a separate feature, likely the x,y are in the airfoil frame (not rotated). Let me check by looking at whether the chord line is horizontal. Let me look at a few airfoils.
CPU-only (16 cores), small model , fine. The extrapolation structure is crystal clear: train/val velocities are 31–75, while `public_test` is 75–82. Critically, **my val set does NOT test velocity extrapolation**, so I'll need to build my own held-out high-velocity split to measure it. Let me first understand the geometry and the physics of how C_D/C_L depend on velocity.
bash
cd /app && python3 -c "
import torch, numpy as np
tr = torch.load('data/train/split.pt', weights_only=True)
pts=tr['points']
# Look at one case geometry
c0=pts[0]
print('case0 x range', c0[:,0].min().item(), c0[:,0].max().item())
print('case0 y range', c0[:,1].min().item(), c0[:,1].max().item())
# Are points ordered around contour? print first/last few x
print('first 8 x:', np.round(c0[:8,0].numpy(),3))
print('first 8 y:', np.round(c0[:8,1].numpy(),3))
print('last 8 x:', np.round(c0[-8:,0].numpy(),3))
# Check chord line: y at x near 0 and x near 1
import numpy as np
x=c0[:,0].numpy(); y=c0[:,1].numpy()
le=np.argmin(x); te=np.argmax(x)
print('LE point (x,y):', round(x[le],3), round(y[le],3))
print('TE point (x,y):', round(x[te],3), round(y[te],3))
print('mean y:', round(y.mean(),4))
"
output
case0 x range -0.0007670827908441424 1.0
case0 y range -0.06596291810274124 0.091779924929142
first 8 x: [-0.001 -0.001  0.802 -0.001  0.051 -0.001 -0.001  0.982]
first 8 y: [0.006 0.006 0.037 0.007 0.059 0.005 0.006 0.004]
last 8 x: [ 0.619  0.776  0.002  0.914  0.528 -0.001  0.75   0.728]
LE point (x,y): -0.001 0.006
TE point (x,y): 1.0 0.0
mean y: 0.0054
The points are NOT ordered around the contour (they're shuffled/sampled). The TE is at (1, 0), LE near (0, ~0.006). The chord is along x from 0 to 1. The airfoil is in its own frame (not rotated by aoa), since aoa is a separate feature. Good , this is permutation-invariant point cloud (consistent with PointNet max-pool). Now let me extract geometric descriptors to control for shape and study the velocity effect on C_D. Let me compute for each case: max thickness, max camber, thickness distribution. Since points are unordered, I'll bin by x and compute upper/lower surfaces. Actually simpler: compute summary stats that are permutation invariant: max y, min y, std of y, mean y, and quantiles. Let me build a decent regression to predict C_D and C_L from [aoa, geom..., velocity] and examine the partial effect of velocity. I'll use these engineered features with a RandomForest or GBM to capture nonlinearity, then check partial dependence on velocity. Actually , my main goal is to build the best PointNet. Let me be systematic: 1. Build pseudo-extrapolation CV: train on low-velocity, validate on high-velocity subset of train. Use it to pick strategy. 2. Candidate strategies for velocity extrapolation: a. Baseline: standardize all 4 features with train stats, MSE on standardized targets. b. Velocity augmentation: during training, randomly scale/shift velocity (and maybe extend beyond training range) while keeping targets fixed , teaches weak/no velocity dependence → robust extrapolation. c. Reduce velocity influence: maybe drop velocity or down-weight it. But we can't change architecture/inputs (must feed 4 channels). But I could set velocity's contribution small via feat_std huge? That makes standardized velocity ~0, so network sees ~constant → effectively ignores velocity. That's a way to "drop" velocity via the affine transform! If feat_std for velocity is set very large, (v - mean)/std ≈ 0 for all, so the network gets no velocity info and predicts from geometry+aoa only. That's one extreme. d. Geometry/aoa based: full reliance. Let me think about which is best. The velocity (Reynolds) effect on C_D is real but weak. If I ignore velocity entirely, I lose that. But extrapolating the velocity effect beyond training range is risky. Let me quantify: how much does ignoring velocity hurt vs. the risk of bad extrapolation? Let me measure with the pseudo-extrapolation split. Let me also consider: a physically-motivated encoding. The drag has two parts: friction drag (decreases with Re) and pressure drag. The relationship C_D vs Re is smooth and monotonic (decreasing). If the network learns a monotstrong decreasing function within [31,75], extrapolating to [75,82] slightly beyond , a smooth monotonic extrapolation could be fine IF the network learned a simple enough function. But neural nets with BatchNorm and maxpool can do weird things. Let me take the empirical route. Let me write a flexible training script and a pseudo-extrapolation evaluation, then test strategies. Let me first establish the evaluation metric precisely. mean_nrmse. I'll define NRMSE per target = RMSE / (something). Common: RMSE normalized by std of true, or by range (max-min), or by mean of |true|. Let me compute all variants during eval so I can reason. Since I don't know the exact normalizer and test targets are hidden, I'll optimize a robust objective: minimize per-target RMSE in standardized space (equivalent to RMSE/std_train per target), and report. Actually, for model selection I should mimic the likely metric. Let me define nrmse with normalization by the std of the TRUE targets in the eval set. That's the most standard "normalized RMSE". I'll compute it on my pseudo-extrapolation val. But careful: if normalization is by std of eval-set true targets, and my pseudo-extrap val has different spread, the normalizer changes. For model comparison it's fine as long as consistent. Let me also compute R^2-like and raw RMSE. Let me get started. …[truncated]
Points are unordered (permutation-invariant cloud), geometry is in the airfoil frame with chord along x∈[0,1], and AoA is separate. Let me check whether shapes/AoA repeat across different velocities , this tells me whether I can directly measure the Reynolds effect on the coefficients.
bash
cd /app && python3 -c "
import torch, numpy as np
tr = torch.load('data/train/split.pt', weights_only=True)
pts, tg = tr['points'], tr['targets']
N=pts.shape[0]
# geometry signature: sorted rounded coords
def sig(c):
    x=c[:,0].numpy(); y=c[:,1].numpy()
    idx=np.lexsort((y,x))
    return tuple(np.round(np.concatenate([x[idx],y[idx]]),4))
sigs=[sig(pts[i]) for i in range(N)]
uniq=set(sigs)
print('unique geometries:', len(uniq), 'of', N)
aoa=pts[:,0,3].numpy()
vel=pts[:,0,2].numpy()
print('unique aoa (rounded 4):', len(set(np.round(aoa,4))))
print('unique vel (rounded 3):', len(set(np.round(vel,3))))
# group by geometry, see if same geom has multiple velocities
from collections import defaultdict
g=defaultdict(list)
for i,s in enumerate(sigs): g[s].append(i)
multi=[v for v in g.values() if len(v)>1]
print('geometries appearing >1 time:', len(multi))
if multi:
    for grp in multi[:5]:
        print('  grp size',len(grp),'vels',np.round(vel[grp],1),'aoa',np.round(aoa[grp],3),'CD',np.round(tg[grp,0].numpy(),4),'CL',np.round(tg[grp,1].numpy(),3))
"
output
unique geometries: 630 of 630
unique aoa (rounded 4): 587
unique vel (rounded 3): 623
geometries appearing >1 time: 0
Every case is a unique (geometry, aoa, velocity) combination , there are no repeated shapes. So I can't directly isolate the Reynolds effect by matching. I'll need a regression/model-based approach to understand the velocity partial effect, or just rely on the empirical pseudo-extrapolation test. Let me build engineered geometric features and fit a flexible model (e.g., gradient boosting via sklearn if available, else a simple approach) to examine partial dependence on velocity. Let me check sklearn availability. Actually, the cleaner and most decision-relevant experiment is the pseudo-extrapolation test with the actual PointNet. Let me focus there. But understanding velocity's partial effect helps me design augmentation target-adjustment. Let me do a quick regression with geometry features. Let me check sklearn.
Every case is a unique (geometry, AoA, velocity) triple , no repeats , so I can't isolate the Reynolds effect by direct matching. Let me check available libraries and then build engineered geometry features to study velocity's partial effect via regression.
bash
cd /app && python3 -c "
import importlib
for m in ['sklearn','numpy','scipy','pandas','matplotlib']:
    try:
        mod=importlib.import_module(m); print(m, getattr(mod,'__version__','?'))
    except Exception as e:
        print(m, 'MISSING')
"
output
sklearn MISSING
numpy 2.1.2
scipy MISSING
pandas MISSING
matplotlib MISSING
Only numpy and torch available. No sklearn/scipy. I'll implement my own regression/analysis with numpy/torch. That's fine. Let me build geometric features per case and do a linear regression (with polynomial/interaction terms) using numpy least squares to examine the velocity partial effect on C_D and C_L. I'll engineer: - aoa, aoa^2 - thickness measures: I need upper/lower surface. Since points unordered, bin by x into say 16 bins, compute max y and min y per bin → gives thickness profile. Then features: max thickness, camber (mean of (max+min)/2), thickness at quarter chord, etc. Actually, for studying the partial effect of velocity, I can include a rich geometry basis and then look at the velocity coefficient. Let me engineer a modest set and regress. Let me write a helper to compute geometry features via x-binning.
Only `numpy` and `torch` are available. I'll implement analysis myself. Let me engineer geometry features (via x-binning of the unordered cloud) and run a regression to estimate velocity's *partial* effect on C_D and C_L after controlling for shape and AoA.
bash
cd /app && cat > /tmp/geom.py << 'EOF'
import torch, numpy as np

def geom_feats(pts, nbins=20):
    # pts: [N,256,4] -> geometry descriptors from x,y (unordered)
    N=pts.shape[0]
    X=pts[:,:,0].numpy(); Y=pts[:,:,1].numpy()
    feats=[]
    edges=np.linspace(0,1,nbins+1)
    for i in range(N):
        x=X[i]; y=Y[i]
        row=[]
        # thickness & camber profile per bin
        thick=[]; camber=[]
        for b in range(nbins):
            m=(x>=edges[b])&(x<edges[b+1])
            if m.sum()>=2:
                yb=y[m]
                thick.append(yb.max()-yb.min())
                camber.append((yb.max()+yb.min())/2)
            else:
                thick.append(0.0); camber.append(0.0)
        thick=np.array(thick); camber=np.array(camber)
        row.append(thick.max())            # max thickness
        row.append(edges[:-1][np.argmax(thick)]) # x of max thickness
        row.append(np.abs(camber).max())   # max |camber|
        row.append(camber.mean())          # mean camber
        row.append(camber[nbins//2])       # mid camber
        row.append(y.max()); row.append(y.min())
        row.append(y.mean()); row.append(y.std())
        feats.append(row)
    return np.array(feats)

if __name__=='__main__':
    tr=torch.load('data/train/split.pt',weights_only=True)
    pts,tg=tr['points'],tr['targets']
    G=geom_feats(pts)
    aoa=pts[:,0,3].numpy(); vel=pts[:,0,2].numpy()
    cd=tg[:,0].numpy(); cl=tg[:,1].numpy()
    # build design matrix: geometry + aoa, aoa^2, aoa*thick, velocity terms
    names=[]; cols=[]
    def add(n,c): names.append(n); cols.append(c)
    add('1',np.ones(len(cd)))
    for j in range(G.shape[1]): add(f'g{j}',G[:,j])
    add('aoa',aoa); add('aoa2',aoa**2); add('aoa3',aoa**3)
    add('aoa*maxth',aoa*G[:,0]); add('aoa*camber',aoa*G[:,3])
    # velocity features (standardized)
    vz=(vel-vel.mean())/vel.std()
    add('vel',vz); add('vel2',vz**2)
    A=np.stack(cols,1)
    # standardize columns (except intercept) for conditioning
    for target,name in [(cd,'C_D'),(cl,'C_L')]:
        coef,res,rank,sv=np.linalg.lstsq(A,target,rcond=None)
        pred=A@coef
        ss=1-((target-pred)**2).sum()/((target-target.mean())**2).sum()
        print(f'=== {name} regression R^2={ss:.4f} ===')
        # report velocity coeffs and their magnitude relative to target std
        for n in ['vel','vel2']:
            k=names.index(n); print(f'  coef[{n}]={coef[k]:.5f}')
        # partial effect: change in prediction from vel min->max holding others
        vzr=np.linspace(vz.min(),vz.max(),5)
        base=coef[names.index('vel')]*vzr+coef[names.index('vel2')]*vzr**2
        print('  vel partial effect across range:',np.round(base-base[0],5))
        print('  target std:',round(target.std(),5))
EOF
python3 /tmp/geom.py
output
=== C_D regression R^2=0.8388 ===
  coef[vel]=-0.00070
  coef[vel2]=-0.00002
  vel partial effect across range: [ 0.      -0.00054 -0.00112 -0.00173 -0.00237]
  target std: 0.0051
=== C_L regression R^2=0.9927 ===
  coef[vel]=0.00410
  coef[vel2]=0.00052
  vel partial effect across range: [0.      0.00237 0.0055  0.00939 0.01403]
  target std: 0.57574
Very informative. With a linear model controlling for geometry and aoa: - C_L: R^2 = 0.9927 , lift is almost fully explained by geometry + aoa. The velocity partial effect across the whole range is ~0.014, tiny relative to C_L std of 0.576 (about 2.4% of std). So velocity barely affects C_L. Good. - C_D: R^2 = 0.8388 (harder). The velocity partial effect across the range is ~-0.0024 (C_D decreases with velocity, consistent with Reynolds drag reduction). Relative to C_D std of 0.0051, that's about -0.46 std across the full velocity range. So velocity DOES matter meaningfully for C_D , about half a standard deviation of effect across the velocity range. This is not negligible for C_D. So for C_D, the Reynolds/velocity effect is real and meaningful (~0.5 std across range). For C_L, velocity is negligible. Now the extrapolation: test velocities are ~7-10 m/s above training max (75). The C_D continues to decrease with velocity. If I ignore velocity for C_D, I'd overpredict C_D at high velocity. The slope: from the regression, d(C_D)/d(vz) ≈ -0.0007 per unit vz, vz std=1 corresponds to ~12.8 m/s. So per m/s, dC_D ≈ -0.0007/12.8 ≈ -5.5e-5. Plus the quadratic. Over the extrapolation of ~7 m/s beyond training mean... Actually let me think in terms of the effect from training region to test region. Actually the key point: C_D has a real, smooth, monotonic decreasing dependence on velocity. To extrapolate well on C_D, the model should capture this trend and extend it. If it learns a roughly linear (or gently quadratic) decreasing relationship, extrapolating slightly beyond is reasonable. But neural networks don't naturally extrapolate linearly, especially with the standardization and the max-pool. Let me think about how to encourage good extrapolation. Given the findings: - C_L: make the model essentially velocity-independent (it already barely depends). Robust. - C_D: capture the monotonic decreasing velocity trend and extrapolate it. Now, the crucial modeling challenge. The PointNet gets velocity as a per-point constant feature. After the shared MLP + maxpool, velocity influences the global feature. The head maps to outputs. The velocity dependence learned is some nonlinear function. For good extrapolation on C_D, I want the learned velocity-dependence to be monotonic and smooth, extending the training trend. Ideas to improve C_D extrapolation: 1. **Augmentation**: During training, extrapolate velocity by generating synthetic high-velocity samples. But I don't have ground truth at high velocity. However, I can fit a physical trend for C_D vs velocity and use it to create synthetic samples at higher velocity. Risky (depends on model correctness). 2. **Feature design within affine constraint**: I can only affinely transform the 4 inputs. BUT , I could consider a clever trick. Wait, can I? The eval does (points - feat_mean)/feat_std then forward. The 4 channels are fixed (x, y, vel, aoa). I can't add channels. So no. Hmm, but actually , is it strictly required that feat_mean/feat_std are used exactly as (points-mean)/std? The task says they "standardize the point features before the forward pass". So yes, affine only. 3. **Physics-informed target transform**: I control targ_mean/targ_std (affine on outputs). Could I predict something smarter? No , the de-standardized output must be [C_D, C_L] directly: pred = out*targ_std+targ_mean. Affine only. So my levers: (a) the weights via training procedure, (b) affine in/out normalization, (c) loss, augmentation, schedule, model selection, ensembling (wait, ensembling , the checkpoint is a single state_dict loaded into one model; I can't ensemble multiple networks at eval since only one state_dict is loaded). Actually, the contract loads one state_dict into one PointNet. So no ensembling at inference. I must produce ONE set of weights. Wait, could I ensemble by training multiple models and averaging their weights? Weight averaging (e.g., SWA) is valid , it's one state_dict. Avera …[truncated]
This is the decisive finding. Controlling for geometry and AoA: - **C_L is ~99% explained by geometry+AoA**, with velocity contributing only ~2.4% of its std → essentially velocity-independent. - **C_D depends meaningfully on velocity**: a monotonic *decreasing* trend (Reynolds drag reduction) worth ~0.5 std across the velocity range. Extrapolating to vel≈78 (25 m/s above the training mean) implies true C_D is ~1.3e-3 *lower* than a velocity-agnostic guess , a large systematic error for the `cd_nmae` metric if ignored. So the core challenge is specifically **extrapolating the C_D–velocity trend**. Since my real val set can't test this, I'll build a pseudo-extrapolation split (train on low velocities, validate on held-out high velocities) to measure it directly. Let me build the experimental harness.
bash
cd /app && cat > /tmp/exp.py << 'EOF'
import os, sys, json, time, math
import numpy as np, torch, torch.nn.functional as F
sys.path.insert(0,'/app')
from candidate_model import build_model
CFG=json.load(open('/app/task_config.json'))

def load(split):
    p=torch.load(f'/app/data/{split}/split.pt',weights_only=True)
    return p['points'].float(), (p['targets'].float() if 'targets' in p else None)

def standardize_stats(x):
    flat=x.reshape(-1,x.shape[-1])
    return flat.mean(0), flat.std(0).clamp_min(1e-8)

def nrmse(pred,true):
    # per-target rmse / std(true); returns (cd, cl, mean)
    rmse=torch.sqrt(((pred-true)**2).mean(0))
    std=true.std(0).clamp_min(1e-12)
    n=rmse/std
    return n[0].item(), n[1].item(), n.mean().item()

def metrics(pred,true):
    cd_n,cl_n,mn=nrmse(pred,true)
    cd_mae=(pred[:,0]-true[:,0]).abs().mean().item()
    cd_nmae=cd_mae/true[:,0].abs().mean().item()
    raw_cd=torch.sqrt(((pred[:,0]-true[:,0])**2).mean()).item()
    raw_cl=torch.sqrt(((pred[:,1]-true[:,1])**2).mean()).item()
    return dict(cd_nrmse=cd_n,cl_nrmse=cl_n,mean_nrmse=mn,worst_nrmse=max(cd_n,cl_n),
                cd_nmae=cd_nmae,rmse_cd=raw_cd,rmse_cl=raw_cl)

def train_model(xtr,ytr,cfg,feat_mean,feat_std,targ_mean,targ_std,seed=0,verbose=False):
    torch.manual_seed(seed); np.random.seed(seed)
    model=build_model(CFG)
    ep=cfg.get('epochs',120); bs=cfg.get('bs',32)
    lr=cfg.get('lr',1e-3); wd=cfg.get('wd',1e-4)
    opt=torch.optim.Adam(model.parameters(),lr=lr,weight_decay=wd)
    sched=torch.optim.lr_scheduler.CosineAnnealingLR(opt,T_max=ep)
    n=xtr.shape[0]
    fm=feat_mean.view(1,1,-1); fs=feat_std.view(1,1,-1)
    tm=targ_mean.view(1,-1); ts=targ_std.view(1,-1)
    jit=cfg.get('jitter',0.0); vel_aug=cfg.get('vel_aug',None)
    wcd=cfg.get('wcd',1.0); wcl=cfg.get('wcl',1.0)
    loss_type=cfg.get('loss','mse')
    slope=cfg.get('cd_slope',0.0)  # physical dC_D/dvel (raw units per m/s)
    swa=cfg.get('swa',False); swa_start=int(ep*0.75)
    swa_state=None; swa_n=0
    for e in range(ep):
        model.train()
        perm=torch.randperm(n)
        for s in range(0,n,bs):
            idx=perm[s:s+bs]
            xb=xtr[idx].clone(); yb=ytr[idx].clone()  # raw units
            # ---- augmentation in RAW space ----
            if jit>0:
                xb[:,:,:2]+=torch.randn_like(xb[:,:,:2])*jit
            if vel_aug is not None:
                mode,lo,hi=vel_aug
                B=xb.shape[0]
                newv=torch.empty(B).uniform_(lo,hi)
                oldv=xb[:,0,2].clone()
                xb[:,:,2]=newv.view(-1,1)
                if mode=='physics':
                    yb[:,0]=yb[:,0]+slope*(newv-oldv)  # adjust C_D
                # mode=='invariant' -> keep targets
            # standardize
            xs=(xb-fm)/fs
            ys=(yb-tm)/ts
            opt.zero_grad(set_to_none=True)
            out=model(xs)
            diff=out-ys
            if loss_type=='huber':
                d=0.01
                per=torch.where(diff.abs()<d,0.5*diff**2/d,diff.abs()-0.5*d)
            else:
                per=diff**2
            loss=(wcd*per[:,0]+wcl*per[:,1]).mean()
            loss.backward(); opt.step()
        sched.step()
        if swa and e>=swa_start:
            with torch.no_grad():
                sd={k:v.detach().clone() for k,v in model.state_dict().items()}
                if swa_state is None:
                    swa_state=sd; swa_n=1
                else:
                    swa_n+=1
                    for k in swa_state:
                        if swa_state[k].dtype.is_floating_point:
                            swa_state[k]+=(sd[k]-swa_state[k])/swa_n
    if swa and swa_state is not None:
        model.load_state_dict(swa_state)
        # recompute BN stats
        model.train()
        with torch.no_grad():
            for s in range(0,n,bs):
                xb=xtr[s:s+bs]; xs=(xb-fm)/fs; model(xs)
    model.eval()
    return model

def predict(model,x,feat_mean,feat_std,targ_mea
…[truncated]
output
harness ready
Now let me set up the pseudo-extrapolation experiment. I'll split the training data by velocity: train on the lower velocities, hold out the highest velocities as a pseudo-test. Then evaluate strategies. Let me also keep the real val set for reference (in-distribution). Let me write a driver that: 1. Loads train. 2. Splits by velocity threshold (e.g., train vel < 66, test vel >= 66) , mimicking extrapolation. Let me check how many cases that gives. 3. Computes feat stats from the TRAIN subset only (to mimic real scenario where stats come from available training data). 4. Runs various configs, reports metrics on held-out high-velocity set. Let me pick the threshold so the held-out set is a reasonable size (~80-120 cases) and clearly above the train subset. Let me check counts.
Now the pseudo-extrapolation driver. I'll split training data by velocity (train on low, test on held-out high velocities) to directly measure C_D extrapolation, mirroring the real train→test gap.
bash
cd /app && python3 -c "
import torch,numpy as np
pts=torch.load('data/train/split.pt',weights_only=True)['points']
v=pts[:,0,2].numpy()
for t in [62,64,66,68]:
    print(f'thresh {t}: train(<{t})={int((v<t).sum())}  heldout(>= {t})={int((v>=t).sum())}  heldout vel range [{v[v>=t].min():.1f},{v[v>=t].max():.1f}]')
"
output
thresh 62: train(<62)=440  heldout(>= 62)=190  heldout vel range [62.3,74.9]
thresh 64: train(<64)=468  heldout(>= 64)=162  heldout vel range [64.1,74.9]
thresh 66: train(<66)=497  heldout(>= 66)=133  heldout vel range [66.0,74.9]
thresh 68: train(<68)=535  heldout(>= 68)=95  heldout vel range [68.0,74.9]
I'll use threshold 64: train on vel<64 (468 cases), hold out vel>=64 (162 cases, vel 64-75). The held-out region extends ~11 m/s above the train max (64). This mimics the real extrapolation (test is ~7 above train max of 75, and up to 82). Good enough to be a meaningful test. Actually the real extrapolation distance is 82-75 = 7 beyond max, but also the bulk of test (75-82) vs train max 75. My pseudo: heldout 64-75 vs train max 64, so up to 11 beyond , a bit more aggressive, which is good for stress-testing. I'll evaluate on the held-out set but maybe focus on the highest-velocity portion (e.g., vel>=70) as the hardest extrapolation, analogous to real test being well above. Let me run the baseline and a few strategies. I'll run multiple seeds for stability since results can be noisy with small data. Let me start with a quick single-seed comparison to see signal, then add seeds. Let me write the driver.
I'll use threshold 64: train on vel<64 (468 cases), evaluate on held-out vel≥64 (162 cases, up to 11 m/s beyond the train max). Let me run a first comparison of core strategies, averaging over seeds for stability.
bash
cd /app && cat > /tmp/run1.py << 'EOF'
import sys,time,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope

pts,tg=load('train')
v=pts[:,0,2]
thr=64.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]
xte,yte=pts[tem],tg[tem]
# hardest sub-region: highest velocities
hardm=v[tem]>=70
print(f'train={xtr.shape[0]} heldout={xte.shape[0]} hardest(>=70)={int(hardm.sum())}')

feat_mean,feat_std=standardize_stats(xtr)
targ_mean=ytr.mean(0); targ_std=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
print('estimated C_D slope per m/s:',slope)

def evalcfg(name,cfg,seeds=(0,1,2)):
    accs=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,feat_mean,feat_std,targ_mean,targ_std,seed=sd)
        pred=predict(m,xte,feat_mean,feat_std,targ_mean,targ_std)
        accs.append(metrics(pred,yte))
    # average
    avg={k:float(np.mean([a[k] for a in accs])) for k in accs[0]}
    print(f'{name:22s} mean_nrmse={avg[\"mean_nrmse\"]:.4f} cd_nrmse={avg[\"cd_nrmse\"]:.4f} cl_nrmse={avg[\"cl_nrmse\"]:.4f} cd_nmae={avg[\"cd_nmae\"]:.4f} rmse_cd={avg[\"rmse_cd\"]:.5f}')
    return avg

base={'epochs':120,'bs':32,'lr':1e-3,'wd':1e-4}
t0=time.time()
evalcfg('baseline',base)
print('one config (3 seeds) took %.1fs'%(time.time()-t0))
evalcfg('jitter0.005',{**base,'jitter':0.005})
evalcfg('vel_invariant',{**base,'vel_aug':('invariant',30,90)})
evalcfg('vel_physics',{**base,'vel_aug':('physics',30,90),'cd_slope':slope})
EOF
time python3 /tmp/run1.py
output
[stderr]
File "/tmp/run1.py", line 28
    print(f'{name:22s} mean_nrmse={avg[\"mean_nrmse\"]:.4f} cd_nrmse={avg[\"cd_nrmse\"]:.4f} cl_nrmse={avg[\"cl_nrmse\"]:.4f} cd_nmae={avg[\"cd_nmae\"]:.4f} rmse_cd={avg[\"rmse_cd\"]:.5f}')
                                                                                                                                                                                            ^
SyntaxError: f-string expression part cannot include a backslash

real	0m0.155s
user	0m0.100s
sys	0m0.040s
The f-string backslash issue (Python 3.11 or earlier). Let me fix by using single quotes inside with different quoting or precomputing.
bash
cd /app && sed -i "s/print(f'{name:22s} mean_nrmse.*$/pr=avg; print('%-22s mean_nrmse=%.4f cd_nrmse=%.4f cl_nrmse=%.4f cd_nmae=%.4f rmse_cd=%.5f'%(name,pr['mean_nrmse'],pr['cd_nrmse'],pr['cl_nrmse'],pr['cd_nmae'],pr['rmse_cd']))/" /tmp/run1.py
time python3 /tmp/run1.py
output
[stderr]
Shell command timed out.
Tool interaction exceeded 300 seconds.
bash
restart: true
output
<system>tool has been restarted.</system>
The run timed out. 120 epochs × 4 configs × 3 seeds is too slow on CPU within 300s. Let me time a single training run first to calibrate, and limit torch threads appropriately. Let me run a single config in the background and measure. Let me first benchmark one training run of, say, 120 epochs.
Training is slower than expected on CPU. Let me benchmark a single run and set thread counts, running in the background to avoid timeouts.
bash
cd /app && cat > /tmp/bench.py << 'EOF'
import sys,time; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics
pts,tg=load('train')
v=pts[:,0,2]; trm=v<64; xtr,ytr=pts[trm],tg[trm]
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
for ep in [40]:
    t0=time.time()
    m=train_model(xtr,ytr,{'epochs':ep,'bs':32,'lr':1e-3,'wd':1e-4},fm,fs,tm,ts,seed=0)
    print('epochs=%d took %.1fs (%.2fs/epoch)'%(ep,time.time()-t0,(time.time()-t0)/ep))
EOF
nohup python3 /tmp/bench.py > /tmp/bench.log 2>&1 &
echo "started pid $!"
output
started pid 434
bash
sleep 45 && cat /tmp/bench.log
output
epochs=40 took 24.1s (0.60s/epoch)
0.6s/epoch with 8 threads on 468 samples. So 120 epochs ≈ 72s per run. With 3 seeds and 4 configs that's ~14 min → too long for one 300s call. I need to run experiments in the background and poll, or reduce cost. Let me check if more threads help, and whether batch matrix ops can be sped up. Actually the bottleneck is likely the many small Conv1d ops. Let me try more threads (16) and a larger batch to reduce overhead. Let me also consider reducing epochs to 80 and seeds to 2 for screening. Let me test thread scaling quickly.
~0.6s/epoch. I'll run experiments in the background and poll. Let me check thread scaling and batch size effects to speed things up.
bash
cd /app && cat > /tmp/bench2.py << 'EOF'
import sys,time; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch
from exp import load,standardize_stats,train_model
pts,tg=load('train')
v=pts[:,0,2]; trm=v<64; xtr,ytr=pts[trm],tg[trm]
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
for nt,bs in [(4,64),(8,64),(16,64),(8,128)]:
    torch.set_num_threads(nt)
    t0=time.time()
    m=train_model(xtr,ytr,{'epochs':20,'bs':bs,'lr':1e-3,'wd':1e-4},fm,fs,tm,ts,seed=0)
    print('threads=%d bs=%d: %.2fs/epoch'%(nt,bs,(time.time()-t0)/20))
EOF
nohup python3 /tmp/bench2.py > /tmp/bench2.log 2>&1 &
echo started
output
started
bash
sleep 60 && cat /tmp/bench2.log
output
threads=4 bs=64: 0.81s/epoch
threads=8 bs=64: 0.49s/epoch
threads=16 bs=64: 0.48s/epoch
threads=8 bs=128: 0.63s/epoch
Best: 8 threads, bs=64 → 0.49s/epoch. Larger batch (128) is slower per epoch (but fewer steps... no, it measured per epoch wall time, 0.63 slower). bs=64 with 8 threads is good. Let me use bs=32 or 64. bs=64 seems efficient. Let me use 8 threads, bs=64. For screening: 100 epochs × 0.49 ≈ 49s/run. 2 seeds × 4 configs = 8 runs ≈ 6.5 min. Still > 300s. I'll run the whole comparison in the background and poll with sleeps. Let me write a robust experiment runner that writes results to a file as it goes, running fully in the background. I'll poll it. Let me rewrite run1 to: set threads=8, bs=64, epochs=100, seeds=(0,1), and append each result to a log as computed. Then I poll. Let me also add the "kill velocity" strategy (set feat_std[2] huge). And focus evaluation on the hardest region too. Let me restructure to save results to JSON incrementally.
Best config: 8 threads, bs=64 (~0.49s/epoch). I'll run the full strategy comparison in the background, writing results incrementally as each finishes, then poll.
bash
cd /app && cat > /tmp/run1.py << 'EOF'
import sys,time,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope

pts,tg=load('train')
v=pts[:,0,2]; thr=64.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
vte=v[tem]; hardm=vte>=70
feat_mean,feat_std=standardize_stats(xtr)
targ_mean=ytr.mean(0); targ_std=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)

results={}
def log(s):
    open('/tmp/run1.log','a').write(s+'\n')
log('train=%d heldout=%d hard=%d slope=%.2e'%(xtr.shape[0],xte.shape[0],int(hardm.sum()),slope))

def evalcfg(name,cfg,fm=None,seeds=(0,1)):
    fmm=feat_mean if fm is None else fm
    accs=[];accsh=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fmm,feat_std,targ_mean,targ_std,seed=sd)
        pred=predict(m,xte,fmm,feat_std,targ_mean,targ_std)
        accs.append(metrics(pred,yte))
        accsh.append(metrics(pred[hardm],yte[hardm]))
    avg={k:float(np.mean([a[k] for a in accs])) for k in accs[0]}
    avgh={k:float(np.mean([a[k] for a in accsh])) for k in accsh[0]}
    results[name]={'all':avg,'hard':avgh}
    json.dump(results,open('/tmp/run1_results.json','w'),indent=1)
    log('%-20s | ALL mean=%.4f cd=%.4f cl=%.4f nmae=%.4f | HARD mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(
        name,avg['mean_nrmse'],avg['cd_nrmse'],avg['cl_nrmse'],avg['cd_nmae'],
        avgh['mean_nrmse'],avgh['cd_nrmse'],avgh['cl_nrmse'],avgh['cd_nmae']))

base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4}
evalcfg('baseline',base)
# kill velocity via huge std
fm_kill=feat_mean.clone()
fs=feat_std  # note std still used; set huge std on vel channel
feat_std_kill=feat_std.clone(); feat_std_kill[2]=1e6
evalcfg('vel_killed',base,fm=feat_mean)  # placeholder to keep order
# proper killed: temporarily swap
def evalcfg_killed():
    accs=[];accsh=[]
    for sd in (0,1):
        m=train_model(xtr,ytr,base,feat_mean,feat_std_kill,targ_mean,targ_std,seed=sd)
        pred=predict(m,xte,feat_mean,feat_std_kill,targ_mean,targ_std)
        accs.append(metrics(pred,yte)); accsh.append(metrics(pred[hardm],yte[hardm]))
    avg={k:float(np.mean([a[k] for a in accs])) for k in accs[0]}
    avgh={k:float(np.mean([a[k] for a in accsh])) for k in accsh[0]}
    results['vel_killed']={'all':avg,'hard':avgh}; json.dump(results,open('/tmp/run1_results.json','w'),indent=1)
    log('%-20s | ALL mean=%.4f cd=%.4f cl=%.4f nmae=%.4f | HARD mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(
        'vel_killed',avg['mean_nrmse'],avg['cd_nrmse'],avg['cl_nrmse'],avg['cd_nmae'],
        avgh['mean_nrmse'],avgh['cd_nrmse'],avgh['cl_nrmse'],avgh['cd_nmae']))
evalcfg_killed()
evalcfg('vel_invariant',{**base,'vel_aug':('invariant',30,90)})
evalcfg('vel_physics',{**base,'vel_aug':('physics',30,90),'cd_slope':slope})
evalcfg('jitter',{**base,'jitter':0.004})
log('DONE')
EOF
rm -f /tmp/run1.log /tmp/run1_results.json
nohup python3 /tmp/run1.py > /tmp/run1.stdout 2>&1 &
echo "started pid $!"
output
started pid 600
Wait, I have a redundant 'vel_killed' placeholder call to evalcfg that trains a baseline and stores under 'vel_killed', then I overwrite with evalcfg_killed. That wastes one run (2 seeds × 100 epochs ≈ 98s wasted). Let me not worry; but it's wasteful. Actually it will overwrite results['vel_killed'] so final is correct, just wasted time. Let me just let it run but I could kill and fix. Let me kill and remove the redundant call to save time.
Let me remove a redundant wasted run I accidentally included, then restart.
bash
kill 600 2>/dev/null; cd /app && sed -i "/placeholder to keep order/d" /tmp/run1.py && rm -f /tmp/run1.log /tmp/run1_results.json /tmp/run1.stdout
nohup python3 /tmp/run1.py > /tmp/run1.stdout 2>&1 &
echo "restarted pid $!"
output
restarted pid 624
[stderr]
[3]+  Terminated              nohup python3 /tmp/run1.py > /tmp/run1.stdout 2>&1
bash
sleep 180 && echo "=== log ===" && cat /tmp/run1.log 2>/dev/null; echo "=== stdout tail ==="; tail -3 /tmp/run1.stdout 2>/dev/null
output
=== log ===
train=468 heldout=162 hard=70 slope=-6.16e-05
baseline             | ALL mean=0.1436 cd=0.1752 cl=0.1119 nmae=0.0452 | HARD mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
=== stdout tail ===
One result so far (baseline). Estimated slope -6.16e-5 per m/s (matches my earlier estimate). Baseline on held-out high velocity: mean_nrmse 0.144, cd 0.175, cl 0.112; on hard (>=70): mean 0.183, cd 0.226. Let me wait for the others. Each run ~ 98s; 5 configs total, so ~8 min total. Let me poll again. Note: cd_nmae on hard region 0.066 (6.6%) for baseline , consistent with my prediction that ignoring the trend costs ~ up to 10%. Let me see if physics aug helps.
Baseline established (slope ≈ −6.2e-5/m/s confirmed). On the hardest held-out region, baseline C_D NRMSE is 0.226 and C_D NMAE 6.6%. Let me wait for the velocity-handling strategies.
bash
sleep 210 && cat /tmp/run1.log 2>/dev/null
output
train=468 heldout=162 hard=70 slope=-6.16e-05
baseline             | ALL mean=0.1436 cd=0.1752 cl=0.1119 nmae=0.0452 | HARD mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
vel_killed           | ALL mean=0.2602 cd=0.4842 cl=0.0362 nmae=0.1023 | HARD mean=0.2023 cd=0.3686 cl=0.0360 nmae=0.1037
vel_invariant        | ALL mean=0.2655 cd=0.4802 cl=0.0509 nmae=0.1024 | HARD mean=0.2146 cd=0.3814 cl=0.0479 nmae=0.1025
Interesting results: - baseline: ALL mean 0.144 (cd 0.175, cl 0.112); HARD mean 0.183 (cd 0.226, cl 0.139) - vel_killed: ALL mean 0.260 (cd 0.484, cl 0.036); HARD mean 0.202 (cd 0.369, cl 0.036) - vel_invariant: ALL mean 0.266 (cd 0.480, cl 0.051); HARD mean 0.215 (cd 0.381, cl 0.048) Key observations: 1. Killing velocity (or making invariant) dramatically IMPROVES C_L (cl_nrmse 0.112 → 0.036). Because the baseline was using velocity spuriously for C_L, hurting extrapolation. When velocity is ignored, C_L extrapolates much better (since C_L is velocity-independent). Big win on C_L! 2. But killing/invariant velocity HURTS C_D badly (cd 0.175 → 0.48 on ALL; 0.226 → 0.37 on HARD). Because it ignores the real Reynolds trend, C_D is systematically off (nmae 10%). So we have a tension: - C_L wants velocity IGNORED (robust extrapolation). - C_D wants velocity USED (to capture Reynolds trend). This strongly suggests a strategy where the model uses velocity for C_D but NOT for C_L. But the architecture is a shared trunk with a shared global feature feeding a 2-output head. I can't easily decouple them within the fixed architecture... but the head has separate final linear weights per output. The shared global feature contains velocity info; the head's C_L row could learn to ignore velocity while the C_D row uses it. The problem is the baseline's C_L DOES use velocity (spuriously), giving cl_nrmse 0.112. How to make C_L ignore velocity while C_D uses it? Options: - Per-target augmentation won't directly do it. - Wait , physics augmentation! In physics aug, I vary velocity and adjust C_D (by slope) while keeping C_L fixed. This teaches the model: when velocity changes, C_D changes (by the slope) but C_L does NOT change. This should simultaneously: (a) make C_L velocity-invariant (good for C_L extrapolation), and (b) teach the correct C_D velocity trend (good for C_D extrapolation). This is exactly what we want! Let me see the vel_physics result. Let me wait for vel_physics and jitter. The physics augmentation is the most promising because it decouples: C_L invariant to velocity, C_D follows the physical slope. Let me see.
Crucial finding , there's a **tension**: killing/ignoring velocity dramatically improves C_L extrapolation (0.112→0.036, since C_L is velocity-independent) but wrecks C_D (0.175→0.48, losing the Reynolds trend). The baseline uses velocity *spuriously* for C_L. The ideal is to use velocity for C_D but not C_L , which is exactly what **physics augmentation** (vary velocity, adjust C_D by the slope, keep C_L fixed) should teach. Let me see its result.
bash
sleep 150 && cat /tmp/run1.log 2>/dev/null
output
train=468 heldout=162 hard=70 slope=-6.16e-05
baseline             | ALL mean=0.1436 cd=0.1752 cl=0.1119 nmae=0.0452 | HARD mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
vel_killed           | ALL mean=0.2602 cd=0.4842 cl=0.0362 nmae=0.1023 | HARD mean=0.2023 cd=0.3686 cl=0.0360 nmae=0.1037
vel_invariant        | ALL mean=0.2655 cd=0.4802 cl=0.0509 nmae=0.1024 | HARD mean=0.2146 cd=0.3814 cl=0.0479 nmae=0.1025
vel_physics          | ALL mean=0.2153 cd=0.3800 cl=0.0505 nmae=0.0705 | HARD mean=0.1516 cd=0.2578 cl=0.0455 nmae=0.0719
jitter               | ALL mean=0.1436 cd=0.1546 cl=0.1325 nmae=0.0376 | HARD mean=0.1766 cd=0.1944 cl=0.1588 nmae=0.0523
DONE
Now I have a full picture: - baseline: ALL mean 0.144 (cd 0.175, cl 0.112); HARD mean 0.183 (cd 0.226, cl 0.139) - vel_killed: ALL mean 0.260 (cd 0.484, cl 0.036); HARD mean 0.202 (cd 0.369, cl 0.036) - vel_invariant: ALL mean 0.266 (cd 0.480, cl 0.051); HARD mean 0.215 (cd 0.381, cl 0.048) - vel_physics: ALL mean 0.215 (cd 0.380, cl 0.051); HARD mean 0.152 (cd 0.258, cl 0.046) - jitter: ALL mean 0.144 (cd 0.155, cl 0.133); HARD mean 0.177 (cd 0.194, cl 0.159) Observations: 1. vel_physics: cl improved greatly (0.112→0.051) AND on HARD region cd is 0.258 (vs baseline 0.226). Hmm, on HARD cd, physics (0.258) is slightly WORSE than baseline (0.226)?! But on HARD overall mean, physics 0.152 is best so far (beats baseline 0.183) because cl is much better. But cd on physics is worse than baseline on both ALL (0.38 vs 0.175) and HARD (0.258 vs 0.226). Wait, that's strange. Physics aug should help C_D extrapolation. But C_D got worse vs baseline?? Let me think. Actually the issue: in physics augmentation I'm sampling velocity uniformly in [30,90] and adjusting C_D by slope*(newv - oldv). But the slope I'm using is the GLOBAL average slope (-6.16e-5). However, the relationship might be more complex. More importantly, by augmenting velocity over a huge range [30,90] uniformly, I'm drowning the signal , every sample's velocity is randomized, so the model sees essentially random velocity with C_D adjusted by a fixed linear slope. This forces C_D to be a linear function of velocity with the given slope. If the true relationship has curvature or interactions (e.g., slope depends on geometry/aoa), this linear global slope is too crude, and C_D predictions suffer. Also, by fully randomizing velocity, I lose the actual velocity information correlation present in data. Hmm. Wait, but the baseline gets cd ALL 0.175 which is much better than physics 0.38. So the baseline's learned velocity dependence is better for C_D than my imposed linear slope! Interesting. That means the baseline IS capturing a useful C_D-velocity relationship and extrapolating it reasonably (cd HARD 0.226). The physics aug with global linear slope is too crude and hurts C_D. But the baseline's C_L is bad (0.112) because it overfits velocity for C_L. So what I really want: keep baseline's good C_D behavior, but fix C_L to be velocity-invariant. Idea: **Asymmetric augmentation** , only augment velocity for the C_L target's benefit without disturbing C_D. But it's a shared network... Alternative idea: The jitter result is interesting: jitter (geometry noise) improved cd (0.175→0.155 ALL, 0.226→0.194 HARD) and nmae (0.045→0.038) but WORSENED cl (0.112→0.133). Jitter helps C_D generalization but not C_L. Hmm. Let me think differently. The real issue is C_L using velocity spuriously. Why does baseline C_L extrapolate poorly? Because in training (low velocity), there's some spurious correlation between velocity and C_L (or the network just uses velocity as a feature and extrapolates it weirdly). When velocity goes out of range, C_L prediction degrades. What if I do physics augmentation but with a SMALLER velocity perturbation range and keep it centered near each sample's velocity, rather than fully randomizing? That would preserve most of the real velocity signal for C_D while teaching local invariance of C_L to velocity and the local C_D slope. But the key benefit we need is teaching the model what happens at HIGH velocity (extrapolation). For that we need to push velocity high. Alternative: Let me reconsider. Maybe the best approach is a **combination**: teach C_L velocity-invariance strongly, while letting C_D keep a learned (data-driven) velocity dependence. One clean way: **Two-headed training is not possible** (fixed architecture). But I can shape the loss/augmentation. Let me reconsider physics aug parameters. Perhaps: - Use a milder augmentation probability (not every sample), so the model still sees real data most of the time (preserving t …[truncated]
Now I have a clear picture of the tension: | strategy | C_D (ALL / HARD) | C_L (ALL / HARD) | mean (HARD) | |---|---|---|---| | baseline | 0.175 / 0.226 | 0.112 / 0.139 | 0.183 | | vel_killed | 0.484 / 0.369 | 0.036 / 0.036 | 0.202 | | vel_physics | 0.380 / 0.258 | 0.051 / 0.046 | 0.152 | | jitter | 0.155 / 0.194 | 0.133 / 0.159 | 0.177 | The baseline's own learned C_D–velocity relation extrapolates *better* than my crude global linear slope, but its C_L overfits velocity. My wide physics aug fixed C_L but degraded C_D. I want **baseline-quality C_D + invariant C_L**. Let me refine the augmentation: mix real and augmented samples (probability-based) and add jitter, so the net keeps its good C_D relation while decorrelating C_L.
str_replace_based_edit_tool
command: str_replace
path: /tmp/exp.py
old_str:             if vel_aug is not None:
                mode,lo,hi=vel_aug
                B=xb.shape[0]
                newv=torch.empty(B).uniform_(lo,hi)
                oldv=xb[:,0,2].clone()
                xb[:,:,2]=newv.view(-1,1)
                if mode=='physics':
                    yb[:,0]=yb[:,0]+slope*(newv-oldv)  # adjust C_D
                # mode=='invariant' -> keep targets
new_str:             if vel_aug is not None:
                B=xb.shape[0]
                oldv=xb[:,0,2].clone()
                if isinstance(vel_aug,dict):
                    p=vel_aug.get('p',1.0)
                    if vel_aug['kind']=='band':
                        newv=torch.empty(B).uniform_(vel_aug['lo'],vel_aug['hi'])
                    else:  # local: delta around oldv
                        newv=oldv+torch.empty(B).uniform_(vel_aug['dlo'],vel_aug['dhi'])
                        newv=newv.clamp(vel_aug.get('clo',28.0),vel_aug.get('chi',95.0))
                    mask=(torch.rand(B)<p).float()
                    newv=mask*newv+(1-mask)*oldv
                    use_slope=vel_aug.get('slope',slope) if vel_aug.get('physics',True) else 0.0
                    xb[:,:,2]=newv.view(-1,1)
                    yb[:,0]=yb[:,0]+use_slope*(newv-oldv)
                else:
                    mode,lo,hi=vel_aug
                    newv=torch.empty(B).uniform_(lo,hi)
                    xb[:,:,2]=newv.view(-1,1)
                    if mode=='physics':
                        yb[:,0]=yb[:,0]+slope*(newv-oldv)
output
The file /tmp/exp.py has been edited successfully.
bash
cd /app && cat > /tmp/run2.py << 'EOF'
import sys,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train'); v=pts[:,0,2]; thr=64.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
hardm=v[tem]>=70
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
results={}
def log(s): open('/tmp/run2.log','a').write(s+'\n')
def ev(name,cfg,seeds=(0,1,2)):
    A=[];H=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); A.append(metrics(pr,yte)); H.append(metrics(pr[hardm],yte[hardm]))
    a={k:float(np.mean([x[k] for x in A])) for k in A[0]}; h={k:float(np.mean([x[k] for x in H])) for k in H[0]}
    results[name]={'all':a,'hard':h}; json.dump(results,open('/tmp/run2_results.json','w'),indent=1)
    log('%-22s | ALL mean=%.4f cd=%.4f cl=%.4f nmae=%.4f | HARD mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(
        name,a['mean_nrmse'],a['cd_nrmse'],a['cl_nrmse'],a['cd_nmae'],h['mean_nrmse'],h['cd_nrmse'],h['cl_nrmse'],h['cd_nmae']))
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope}
log('slope=%.3e'%slope)
ev('baseline',base)
ev('phys_band_p0.5',{**base,'vel_aug':{'kind':'band','lo':35,'hi':90,'p':0.5,'physics':True}})
ev('phys_band_p0.7',{**base,'vel_aug':{'kind':'band','lo':35,'hi':90,'p':0.7,'physics':True}})
ev('phys_local_p1',{**base,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':1.0,'physics':True}})
ev('phys_local_p0.5+jit',{**base,'jitter':0.004,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':0.5,'physics':True}})
ev('phys_band_p0.5+jit',{**base,'jitter':0.004,'vel_aug':{'kind':'band','lo':35,'hi':90,'p':0.5,'physics':True}})
log('DONE')
EOF
rm -f /tmp/run2.log /tmp/run2_results.json
nohup python3 /tmp/run2.py > /tmp/run2.stdout 2>&1 &
echo "started pid $!"
output
started pid 714
This will take ~6 configs × 3 seeds × 49s ≈ 15 min. Let me poll periodically. Meanwhile, let me think more. Actually 3 seeds × 6 configs × 100 epochs × 0.49s = ~880s ≈ 15 min. Let me poll in chunks. Let me wait ~280s and check partial. While waiting, let me think about the final strategy and also whether I should reconsider the slope estimation to be more robust (e.g., the slope might be better estimated with interactions or as multiplicative). Also, I should eventually validate the chosen strategy with a DIFFERENT threshold (e.g., 62 or 60) to make sure it generalizes, and check on the real val set (in-distribution) that I'm not hurting in-distribution performance. Let me poll.
Experiment 2 is running (refined augmentation variants, 3 seeds each). Let me poll while it progresses.
bash
sleep 280 && cat /tmp/run2.log 2>/dev/null; echo '---'; tail -2 /tmp/run2.stdout
output
slope=-6.165e-05
baseline               | ALL mean=0.1321 cd=0.1585 cl=0.1057 nmae=0.0396 | HARD mean=0.1648 cd=0.2009 cl=0.1287 nmae=0.0563
---
Only baseline done so far (3 seeds: mean 0.132, cd 0.159, cl 0.106; HARD mean 0.165). Slightly different from run1 baseline due to 3 seeds vs 2. Let me keep waiting. The rest will take ~12 more min. Let me wait in chunks.
bash
sleep 290 && cat /tmp/run2.log 2>/dev/null
output
slope=-6.165e-05
baseline               | ALL mean=0.1321 cd=0.1585 cl=0.1057 nmae=0.0396 | HARD mean=0.1648 cd=0.2009 cl=0.1287 nmae=0.0563
phys_band_p0.5         | ALL mean=0.1835 cd=0.3167 cl=0.0503 nmae=0.0613 | HARD mean=0.1389 cd=0.2261 cl=0.0516 nmae=0.0678
phys_band_p0.7         | ALL mean=0.1912 cd=0.3337 cl=0.0487 nmae=0.0648 | HARD mean=0.1418 cd=0.2336 cl=0.0499 nmae=0.0702
phys_local_p1          | ALL mean=0.1928 cd=0.3347 cl=0.0508 nmae=0.0557 | HARD mean=0.1182 cd=0.1833 cl=0.0531 nmae=0.0530
Now this is very interesting: - baseline: ALL mean 0.132 (cd 0.159, cl 0.106); HARD mean 0.165 (cd 0.201, cl 0.129) - phys_band_p0.5: ALL mean 0.184 (cd 0.317, cl 0.050); HARD mean 0.139 (cd 0.226, cl 0.052) - phys_band_p0.7: ALL mean 0.191 (cd 0.334, cl 0.049); HARD mean 0.142 (cd 0.234, cl 0.050) - phys_local_p1: ALL mean 0.193 (cd 0.335, cl 0.051); HARD mean 0.118 (cd 0.183, cl 0.053) Key: **phys_local_p1** on the HARD (highest velocity, true extrapolation) region: - HARD cd 0.183 , actually BETTER than baseline's 0.201! - HARD cl 0.053 , much better than baseline 0.129! - HARD mean 0.118 vs baseline 0.165. But on ALL (which includes velocities 64-70, closer to training), phys_local_p1 cd is 0.335 (much worse than baseline 0.159). That's because on the milder region (64-70), the global linear slope hurts C_D compared to baseline's learned relation. But on the HARD region (70-75, true extrapolation), phys_local wins on C_D. Wait, why would physics aug be WORSE on the near region (64-70) but BETTER on the far region (70-75)? Because: - Near region (64-70): close to training (train is <64). Baseline's learned C_D(velocity) is accurate here (interpolation/slight extrapolation). Physics global slope is cruder → worse. - Far region (70-75): real extrapolation. Baseline's learned relation starts to break down; physics linear slope extends better → physics wins. Hmm, but ALL includes 64-70 AND 70-75. The "ALL cd" for physics is dominated by poor performance on 64-70. But for the REAL test (velocity 75-82, which is beyond ALL of training including 64-75), the relevant analog is the HARD region and BEYOND. The real test is like "even harder than HARD". So the HARD metric is the most relevant proxy for the real test! So phys_local_p1 looks best for the real scenario: HARD mean 0.118 vs baseline 0.165. But wait , I should be careful. In my pseudo-split, "HARD" = velocity 70-75, and the model trained on <64. So HARD is 6-11 m/s above training max. The real test is 75-82, which is 0-7 m/s above training max (75). So actually the real test's extrapolation distance (0-7 beyond max) is SIMILAR to or slightly less than my HARD region (6-11 beyond max 64). Good, HARD is a reasonable proxy, maybe slightly pessimistic. But there's an important subtlety: in the real final model, I'll train on ALL velocities up to 75. So the learned C_D(velocity) relation is anchored up to 75, and I extrapolate to 82. In my pseudo-experiment, baseline anchored up to 64, extrapolate to 75. The baseline's C_D extrapolation quality depends on how far beyond it goes. Let me reconsider: what matters is which strategy generalizes best just beyond the training velocity ceiling. My HARD region (70-75, i.e., 6-11 beyond ceiling 64) shows phys_local_p1 best. Let me verify this holds at a different threshold too, and let me look even more carefully , maybe define an "extreme" region. Also, let me reconsider: phys_local_p1 uses dlo=-8, dhi=20 local deltas. So velocity perturbed by -8 to +20. From training max 64, +20 → up to 84. So it sees up to ~84 during training via augmentation. That's why it extrapolates to 70-75 well. For the real model (train max 75), local +20 → up to 95, covering test 75-82 well. Let me wait for the last two configs (phys_local_p0.5+jit, phys_band_p0.5+jit). The combination with jitter might help C_D further. Let me also plan a run3 to: 1. Confirm best config at another threshold (62 and 60) to ensure robustness. 2. Tune the local aug range (dhi) and slope. 3. Test on real val set (in-distribution) to ensure no regression there. Let me wait for run2 to finish.
Now a key pattern emerges. **`phys_local_p1`** (local velocity perturbations −8/+20 with slope-adjusted C_D) is best on the **HARD** region (true extrapolation, 70–75, which is 6–11 m/s beyond the training ceiling of 64): - HARD mean **0.118** vs baseline 0.165, with C_D **0.183 < baseline 0.201** and C_L 0.053 ≪ 0.129. The physics aug looks worse on ALL only because the 64–70 band (near training) is where the baseline's learned relation still interpolates well; but the **HARD region is the true analog of the real test** (velocities beyond the training ceiling). Let me see the final two configs.
bash
sleep 150 && cat /tmp/run2.log 2>/dev/null
output
slope=-6.165e-05
baseline               | ALL mean=0.1321 cd=0.1585 cl=0.1057 nmae=0.0396 | HARD mean=0.1648 cd=0.2009 cl=0.1287 nmae=0.0563
phys_band_p0.5         | ALL mean=0.1835 cd=0.3167 cl=0.0503 nmae=0.0613 | HARD mean=0.1389 cd=0.2261 cl=0.0516 nmae=0.0678
phys_band_p0.7         | ALL mean=0.1912 cd=0.3337 cl=0.0487 nmae=0.0648 | HARD mean=0.1418 cd=0.2336 cl=0.0499 nmae=0.0702
phys_local_p1          | ALL mean=0.1928 cd=0.3347 cl=0.0508 nmae=0.0557 | HARD mean=0.1182 cd=0.1833 cl=0.0531 nmae=0.0530
phys_local_p0.5+jit    | ALL mean=0.2823 cd=0.4978 cl=0.0668 nmae=0.0757 | HARD mean=0.1548 cd=0.2414 cl=0.0683 nmae=0.0685
phys_local_p0.5+jit: ALL mean 0.282 (cd 0.498!), HARD 0.155. That's worse , the p=0.5 with local means half the samples keep original velocity, but combined with jitter, C_D got much worse (0.498 ALL). Hmm, that's surprising. Actually p=0.5 local means only half augmented; that's odd it's worse than p=1. Maybe jitter interaction. Anyway phys_local_p1 remains best. Let me wait for the last one (phys_band_p0.5+jit). But I think the winner is phys_local_p1. Let me now plan refinement: - Tune slope magnitude (maybe the true effective slope for good extrapolation differs). - Tune dhi (how far up to augment). - Maybe p slightly below 1 but not with jitter. - Consider removing jitter (it seems to hurt C_D in combo). But before over-tuning, I must validate at another threshold to avoid overfitting to threshold 64. Let me set up run3 that tests the top candidates at thresholds 60 and 62 as well, AND reports in-distribution val performance (train on all <thr, but also check on real val which is in-distribution , though real val has velocities up to 75; if I train only on <64, real val includes 64-75 which is extrapolation; that's not "in-distribution". Instead, to check in-distribution, I should train on ALL train data and eval on real val.) Let me structure the final approach: - The pseudo-split experiments guide the velocity strategy. phys_local_p1 is winning on extrapolation. - Final model: train on ALL 630 training cases with phys_local augmentation, slope estimated from all data, then save checkpoint. But I also want to ensure in-distribution (real val) isn't badly hurt. Let me test: train on all train, eval on real val, for baseline vs phys_local. Real val is in-distribution (31-75), so physics aug might slightly hurt in-distribution C_D (like the ALL region showed). But the REAL TEST is extrapolation, so I should weight the extrapolation proxy more. However, I don't know if the hidden test also includes some in-range cases. The task says "sampled from the higher-speed, higher-Reynolds end", and public_test is 75-82 (all above training). So the hidden test is almost certainly all high-velocity. So extrapolation performance is what matters. I'll prioritize the HARD proxy. Still, I'll verify the final model's real-val numbers for sanity (shouldn't be catastrophic). Let me now think about whether I can do BETTER than phys_local_p1 on C_D extrapolation. The C_D HARD for phys_local is 0.183; baseline 0.201. Can I push C_D lower while keeping C_L low? Ideas: 1. Better slope: maybe use a slightly larger magnitude slope to more aggressively reduce C_D at high velocity (if true relation has the drag continuing to drop). Or estimate slope more robustly (e.g., per the regression with geometry controls gave -6.16e-5; the raw correlation gave different). Let me consider fitting slope via the geometry+aoa regression (that's what estimate_cd_slope does). Good. 2. Combine the net's learned relation with the physics slope: e.g., augment with p<1 but WITHOUT jitter (jitter seemed to hurt). phys_local p=1 was best. Let me try p=0.8, p=1 variants and dhi variants. 3. Maybe a mild multiplicative/curved slope. Keep it simple: linear additive is decent. 4. Two-stage: Actually, let me reconsider , the cleanest might be to detrend C_D in target space AND feed velocity so model learns residual. But I established I can't add back velocity term at eval. However, with augmentation the model learns to add it internally. phys_local does this. Let me also reconsider the possibility that I'm overcomplicating. Let me reexamine: the real metric is mean_nrmse over the two targets on the hidden test. Let me estimate what phys_local would get vs baseline on the real test. My best proxy (HARD): baseline 0.165, phys_local 0.118. That's a ~28% relative improvement. Let me do run3: robustness across thresholds + tuning, focusing on phys_local variants. I'll evaluate on HARD (top velocities) primarily, plus a new "XHARD" = top 50 velocities. Configs for ru …[truncated]
`phys_local_p1` is the clear winner on the true-extrapolation (HARD) region. The `+jit` and `p=0.5` variants hurt C_D, so I'll drop jitter. Now I need to (1) confirm this isn't overfit to threshold 64, and (2) tune the slope magnitude and upward augmentation range. Let me run a tuning sweep at a **different threshold (62)** with an even-higher "XHARD" region, to guard against overfitting my proxy.
bash
cd /app && cat > /tmp/run3.py << 'EOF'
import sys,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train'); v=pts[:,0,2]; thr=62.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
hardm=v[tem]>=68; xhardm=v[tem]>=71
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
results={}
def log(s): open('/tmp/run3.log','a').write(s+'\n')
def ev(name,cfg,seeds=(0,1)):
    H=[];X=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); H.append(metrics(pr[hardm],yte[hardm])); X.append(metrics(pr[xhardm],yte[xhardm]))
    h={k:float(np.mean([x[k] for x in H])) for k in H[0]}; xh={k:float(np.mean([x[k] for x in X])) for k in X[0]}
    results[name]={'hard':h,'xhard':xh}; json.dump(results,open('/tmp/run3_results.json','w'),indent=1)
    log('%-20s | HARD mean=%.4f cd=%.4f cl=%.4f nmae=%.4f | XHARD mean=%.4f cd=%.4f cl=%.4f'%(
        name,h['mean_nrmse'],h['cd_nrmse'],h['cl_nrmse'],h['cd_nmae'],xh['mean_nrmse'],xh['cd_nrmse'],xh['cl_nrmse']))
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope}
log('thr=62 nhard=%d nxhard=%d slope=%.3e'%(int(hardm.sum()),int(xhardm.sum()),slope))
ev('baseline',base)
ev('local_p1_s1.0',{**base,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':1.0}})
ev('local_p1_invariant',{**base,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':1.0,'physics':False}})
ev('local_p1_s1.5',{**base,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':1.0,'slope':slope*1.5}})
ev('local_p1_dhi30',{**base,'vel_aug':{'kind':'local','dlo':-8,'dhi':30,'p':1.0}})
ev('local_p0.8_dhi25',{**base,'vel_aug':{'kind':'local','dlo':-8,'dhi':25,'p':0.8}})
log('DONE')
EOF
rm -f /tmp/run3.log /tmp/run3_results.json
nohup python3 /tmp/run3.py > /tmp/run3.stdout 2>&1 &
echo "started pid $!"
output
started pid 792
This is 6 configs × 2 seeds × ~45s (threshold 62 → 440 train samples, slightly faster) ≈ 9 min. Let me wait. While waiting, let me think about the final deliverable and ensure correctness of the checkpoint format. The checkpoint must contain: - state_dict - feat_mean, feat_std (length-4) - targ_mean, targ_std (length-2) The eval pipeline: x_std = (points - feat_mean)/feat_std; out = model(x_std); pred = out*targ_std + targ_mean. I need to make sure my training matches this exactly. In train_model, I standardize features with fm/fs and targets with tm/ts, and the model predicts standardized targets. predict() de-standardizes. Good. For the final model, feat_mean/feat_std computed from training points (all of them). targ_mean/targ_std from training targets. One more consideration: The augmentation changes velocity inputs to higher values during training. But feat_mean/feat_std are computed from the ORIGINAL training data (velocity 31-75). At test, velocity 75-82 gets standardized with training stats → z-scores ~1.7-2.5. During training with augmentation, velocity goes up to ~95, so the model sees standardized velocities up to ~(95-53)/12.8 ≈ 3.3. So the model is trained on the standardized velocity range that covers test. Good , that's the point. Now, should feat_mean/feat_std for velocity reflect the augmented distribution or original? Since it's just affine and absorbed by first layer, and I compute from original data, it's fine. What matters is the model sees the test z-scores during training (via augmentation). It does. Let me also double check: is there any issue with BatchNorm and the augmented velocity distribution at test? BN running stats are computed during training (on augmented data, since model.train() forward during training updates running stats). At eval, BN uses running stats. The augmented training has velocity spanning wide range, so BN stats for the velocity-derived channels reflect that. At test (velocity 75-82), inputs are within the augmented training range, so BN should be fine. Good. Actually wait , there's subtlety. In train_model, the BN running stats get updated during normal training forward passes on augmented batches. For the final model I should make sure BN running stats are representative. With augmentation producing velocities up to 95, the running stats see a broad range. At test velocity ~78 it's within range. Fine. Now let me also reconsider the slope estimate for the final model (trained on all data). estimate_cd_slope on all 630 gave -6.16e-5 earlier (from geom.py regression it was about -0.0007 per vz where vz std 12.79 → -5.5e-5; estimate_cd_slope gave -6.16e-5). Consistent ~ -6e-5. Good. Let me wait for run3.
Sweep 3 is running at threshold 62 with slope/range variants. Let me think about checkpoint-format correctness while polling. The eval pipeline is `out = model((points-feat_mean)/feat_std)` then `pred = out*targ_std + targ_mean`. My augmentation pushes training velocities up to ~95, so the model learns over the standardized velocity range that *covers* the 75–82 test region , the BN running stats and weights will be trained where they'll be evaluated. Let me check results.
bash
sleep 280 && cat /tmp/run3.log 2>/dev/null
output
thr=62 nhard=95 nxhard=55 slope=-6.265e-05
baseline             | HARD mean=0.2205 cd=0.2772 cl=0.1639 nmae=0.0721 | XHARD mean=0.2241 cd=0.2792 cl=0.1689
local_p1_s1.0        | HARD mean=0.1659 cd=0.2767 cl=0.0552 nmae=0.0581 | XHARD mean=0.1315 cd=0.2108 cl=0.0522
local_p1_invariant   | HARD mean=0.1837 cd=0.3129 cl=0.0545 nmae=0.0579 | XHARD mean=0.1353 cd=0.2195 cl=0.0511
At threshold 62: - baseline: HARD mean 0.221 (cd 0.277, cl 0.164); XHARD mean 0.224 (cd 0.279, cl 0.169) - local_p1_s1.0: HARD mean 0.166 (cd 0.277, cl 0.055); XHARD mean 0.132 (cd 0.211, cl 0.052) - local_p1_invariant: HARD mean 0.184 (cd 0.313, cl 0.055); XHARD mean 0.135 (cd 0.220, cl 0.051) So: - local_p1_s1.0 again wins big over baseline (HARD 0.166 vs 0.221; XHARD 0.132 vs 0.224). - On XHARD (the most extreme, velocity>=71, i.e., 9-13 beyond ceiling 62), local_p1 cd 0.211 vs baseline 0.279 , physics clearly better on C_D at the extreme. And cl 0.052 vs 0.169. Great. - physics (slope) beats invariant on C_D (HARD cd 0.277 vs 0.313; XHARD 0.211 vs 0.220). So the slope helps C_D, confirming physics > invariant. This confirms at a second threshold: local_p1 with slope is robustly best. Let me see the slope1.5 and dhi variants.
Confirmed at a second threshold (62): `local_p1_s1.0` robustly beats baseline on the extreme **XHARD** region (C_D 0.211 vs 0.279, C_L 0.052 vs 0.169), and the slope-adjusted physics beats the invariant version on C_D , validating that the Reynolds slope genuinely helps C_D extrapolation. Let me see the remaining slope/range tuning variants.
bash
sleep 200 && cat /tmp/run3.log 2>/dev/null
output
thr=62 nhard=95 nxhard=55 slope=-6.265e-05
baseline             | HARD mean=0.2205 cd=0.2772 cl=0.1639 nmae=0.0721 | XHARD mean=0.2241 cd=0.2792 cl=0.1689
local_p1_s1.0        | HARD mean=0.1659 cd=0.2767 cl=0.0552 nmae=0.0581 | XHARD mean=0.1315 cd=0.2108 cl=0.0522
local_p1_invariant   | HARD mean=0.1837 cd=0.3129 cl=0.0545 nmae=0.0579 | XHARD mean=0.1353 cd=0.2195 cl=0.0511
local_p1_s1.5        | HARD mean=0.1945 cd=0.3334 cl=0.0555 nmae=0.0916 | XHARD mean=0.1763 cd=0.2999 cl=0.0527
local_p1_dhi30       | HARD mean=0.1797 cd=0.3104 cl=0.0490 nmae=0.0636 | XHARD mean=0.1350 cd=0.2238 cl=0.0462
- local_p1_s1.5 (1.5x slope): worse (HARD cd 0.333, XHARD cd 0.300, nmae 0.092). So overshooting the slope hurts. The estimated slope (1.0x) is better. - local_p1_dhi30 (augment up to +30): HARD cd 0.310, XHARD cd 0.224 , slightly worse than dhi20 (XHARD cd 0.211). cl slightly better (0.046). Overall similar, dhi20 a bit better on cd. So the best remains local_p1_s1.0 with dhi20 (slope=estimated, range -8 to +20). Let me wait for the last config (local_p0.8_dhi25). Summary so far: the winner is local physics augmentation, p=1.0, dlo=-8, dhi=20, slope=estimated (~-6.2e-5). Now let me think about whether I can squeeze more C_D performance. C_D XHARD is ~0.21 which is the main remaining error. Ideas: - The slope is a global average. C_D's velocity sensitivity might depend on the airfoil (thicker airfoils / higher drag have more friction drag → more Reynolds sensitivity). A per-sample slope proportional to the friction component could help. But hard to estimate without more info. Keep global for robustness. - Longer training / schedule / model selection (SWA). Let me test SWA and epochs. - Loss: Huber might help C_D (robust to outliers). Let me test. - Maybe combine local physics aug WITH mild jitter but jitter hurt earlier , but that was with p=0.5. Let me test jitter with p=1 physics. Actually run2 phys_local_p0.5+jit was bad, but that had p=0.5. Let me test p=1 local + small jitter. Let me also reconsider the C_L: it's now ~0.05 which is great. Main lever left is C_D. Let me also reconsider: should dlo be more negative or should I also augment downward to keep low-velocity well-modeled? For the real test (high velocity), downward aug matters less. But to keep the model good across, dlo=-8 is fine. Let me now run run4 to finalize: test on threshold 64 AND 60 (robustness) the top config plus a couple refinements (SWA, Huber, longer epochs, slope 1.2x, combine), 2 seeds, focus on XHARD. Actually, let me be mindful of time budget. I've used a good chunk. Let me do a focused run4 with the most promising refinements at threshold 63 (a fresh threshold) and pick the final. Then build the final model on all data and validate. Let me reconsider: I want to also make sure the final choice is not sensitive to the exact slope (since final slope estimated on all data ≈ -6.2e-5, stable). Good. run4 configs (threshold 63, 2 seeds, eval XHARD vel>=70 and HARD vel>=69): - local_p1 (reference best) - local_p1 + huber - local_p1 + swa (epochs 140, swa from 0.7) - local_p1 + epochs150 - local_p1 + slope1.2 - local_p1 + jitter0.003 Let me define thresholds. thr=63 → train<63 (~455?), test>=63. XHARD vel>=71 (~55), HARD>=69. Let me launch. Actually, slope1.5 was notably worse, so the model is sensitive to slope. slope1.2 might be slightly worse than 1.0. Let me include slope0.8 too to see the curvature of sensitivity; if 0.8 and 1.2 are both worse, 1.0 is near-optimal. But that's more runs. Let me include slope1.2 and slope0.85. Let me keep to 6 configs, 2 seeds. ~6*2*47 ≈ 9.5 min. Let me write run4.
`slope×1.5` overshoots (worse C_D), and `dhi30` is marginally worse than `dhi20` , so the **estimated slope at 1.0× with range [−8,+20]** is the sweet spot. Let me run a final refinement sweep at a fresh threshold (63) testing training-procedure improvements (SWA, Huber, longer schedule, small jitter, slope ±) to squeeze more out of C_D.
bash
cd /app && cat > /tmp/run4.py << 'EOF'
import sys,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train'); v=pts[:,0,2]; thr=63.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
hardm=v[tem]>=69; xhardm=v[tem]>=71
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
results={}
def log(s): open('/tmp/run4.log','a').write(s+'\n')
def ev(name,cfg,seeds=(0,1,2)):
    H=[];X=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); H.append(metrics(pr[hardm],yte[hardm])); X.append(metrics(pr[xhardm],yte[xhardm]))
    h={k:float(np.mean([x[k] for x in H])) for k in H[0]}; xh={k:float(np.mean([x[k] for x in X])) for k in X[0]}
    results[name]={'hard':h,'xhard':xh}; json.dump(results,open('/tmp/run4_results.json','w'),indent=1)
    log('%-18s | HARD mean=%.4f cd=%.4f cl=%.4f | XHARD mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(
        name,h['mean_nrmse'],h['cd_nrmse'],h['cl_nrmse'],xh['mean_nrmse'],xh['cd_nrmse'],xh['cl_nrmse'],xh['cd_nmae']))
VA={'kind':'local','dlo':-8,'dhi':20,'p':1.0}
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope}
log('thr=63 nhard=%d nxhard=%d slope=%.3e'%(int(hardm.sum()),int(xhardm.sum()),slope))
ev('local_p1',{**base,'vel_aug':VA})
ev('local_huber',{**base,'vel_aug':VA,'loss':'huber'})
ev('local_swa',{**base,'epochs':140,'vel_aug':VA,'swa':True})
ev('local_ep160',{**base,'epochs':160,'vel_aug':VA})
ev('local_s0.85',{**base,'vel_aug':{**VA},'cd_slope':slope*0.85})
ev('local_jit003',{**base,'vel_aug':VA,'jitter':0.003})
log('DONE')
EOF
rm -f /tmp/run4.log /tmp/run4_results.json
nohup python3 /tmp/run4.py > /tmp/run4.stdout 2>&1 &
echo "started pid $!"
output
started pid 861
This run has 3 seeds and 6 configs with some longer (140, 160 epochs) → maybe ~12-14 min. Let me wait. I'll poll in chunks of ~290s. While waiting, let me prepare the final training script so I'm ready to generate the checkpoint once I confirm the config. I'll write /app/train.py replacement or a new script /app/final_train.py that: 1. Loads all train data. 2. Computes feat_mean/feat_std from all train points. 3. Computes targ_mean/targ_std from all train targets. 4. Estimates slope from all train data. 5. Trains with local physics augmentation (p=1, dlo=-8, dhi=20, slope). 6. Possibly SWA / ensemble-by-weight-averaging across seeds? Weight averaging across independent seeds generally does NOT work (different basins). SWA along one trajectory works. Let me decide based on run4. 7. Saves checkpoint to /app/outputs/model.pt. Let me also think: should the final model train on ALL data (including val)? The task gives train and val splits. I can use val as additional training data since the hidden test is separate. Using more data (train+val = 710 cases) should help, especially since val has the same distribution. But I should keep val for model selection / sanity. Given the hidden test is extrapolation and I can't select on it, I might as well train on train+val for the final model to maximize data. But I'll first validate the approach training on train only and checking val (in-distribution) to ensure sanity. Then for the final, train on train+val. Actually, careful: I should make sure that including val doesn't change the feat/targ normalization in a bad way , it won't, same distribution. Including val's higher... val max velocity is 74.16, similar. Fine. Let me also reconsider: do I want to incorporate the highest-velocity training samples with MORE weight, or augment the real data's velocity upward specifically? The local aug with dhi=20 already pushes everything up. For the final model (train ceiling 75), dhi=20 pushes to 95, covering test (75-82) with margin. Good. Let me hold on building final until run4 picks SWA/epochs/huber. Let me wait. Let me reconsider one more potential improvement while waiting: the slope estimate. Currently estimate_cd_slope fits C_D ~ geometry(12 thickness bins) + aoa + aoa^2 + aoa^3 + aoa*thick + vel, linear. The vel coefficient is the average slope. This is a decent estimate. For the final model on all data, let me compute it and sanity check magnitude (~-6e-5). One more: I could also make the slope depend on predicted drag level (multiplicative), but that complicates target fabrication. The linear global slope works well empirically. Keep it. Let me wait for run4 partial results.
While run 4 trains, let me draft the final training script so I'm ready. It will train on all data with the winning local-physics augmentation and save the checkpoint in the exact required format.
bash
sleep 60 && cat /tmp/run4.log 2>/dev/null; echo '(partial)'
output
thr=63 nhard=80 nxhard=55 slope=-6.213e-05
(partial)
str_replace_based_edit_tool
command: create
path: /app/final_train.py
file_text: """Final trainer for the airfoil force-coefficient PointNet.

Key idea (see notes): the scored cases live at higher inlet velocity / Reynolds
than training. Physically, C_L is essentially velocity-independent while C_D has
a mild, monotonic decreasing dependence on velocity (Reynolds drag reduction).
We therefore train with a physics-based velocity augmentation: each sample's
inlet velocity is randomly perturbed (biased upward, beyond the test range) and
C_D is shifted by an estimated linear Reynolds slope while C_L is held fixed.
This simultaneously (a) teaches C_L to ignore velocity -> robust extrapolation,
and (b) teaches C_D the correct velocity trend and extends it past the training
ceiling. The architecture and checkpoint contract are unchanged.
"""
from __future__ import annotations
import json, os, sys
from pathlib import Path
import numpy as np, torch, torch.nn.functional as F

APP_DIR = Path(os.environ.get("APP_DIR", "/app"))
sys.path.insert(0, str(APP_DIR))
from candidate_model import build_model
from dataset import load_split

CFG = json.load((APP_DIR / "task_config.json").open())


def estimate_cd_slope(points, cd):
    """Partial slope d(C_D)/d(velocity) controlling for geometry + AoA."""
    X = points[:, :, 0].numpy(); Y = points[:, :, 1].numpy(); N = points.shape[0]
    nb = 12; edges = np.linspace(0, 1, nb + 1); G = []
    for i in range(N):
        x = X[i]; y = Y[i]; th = []
        for b in range(nb):
            m = (x >= edges[b]) & (x < edges[b + 1])
            th.append((y[m].max() - y[m].min()) if m.sum() >= 2 else 0.0)
        G.append(th)
    G = np.array(G)
    aoa = points[:, 0, 3].numpy(); vel = points[:, 0, 2].numpy(); cdn = cd.numpy()
    cols = [np.ones(N)] + [G[:, j] for j in range(nb)] + [aoa, aoa ** 2, aoa ** 3, aoa * G[:, 2], vel]
    A = np.stack(cols, 1)
    coef, *_ = np.linalg.lstsq(A, cdn, rcond=None)
    return float(coef[-1])


def train(points, targets, *, epochs=150, bs=64, lr=1e-3, wd=1e-4, seed=0,
          dlo=-8.0, dhi=20.0, p=1.0, clo=28.0, chi=98.0, swa=True, swa_frac=0.7,
          slope=None, verbose=True):
    torch.manual_seed(seed); np.random.seed(seed)
    fm, fs = _coord_stats(points)
    tm = targets.mean(0); ts = targets.std(0).clamp_min(1e-8)
    if slope is None:
        slope = estimate_cd_slope(points, targets[:, 0])
    model = build_model(CFG)
    opt = torch.optim.Adam(model.parameters(), lr=lr, weight_decay=wd)
    sched = torch.optim.lr_scheduler.CosineAnnealingLR(opt, T_max=epochs)
    n = points.shape[0]
    fmv = fm.view(1, 1, -1); fsv = fs.view(1, 1, -1); tmv = tm.view(1, -1); tsv = ts.view(1, -1)
    swa_start = int(epochs * swa_frac); swa_state = None; swa_n = 0
    for e in range(epochs):
        model.train(); perm = torch.randperm(n)
        for s in range(0, n, bs):
            idx = perm[s:s + bs]
            xb = points[idx].clone(); yb = targets[idx].clone()
            B = xb.shape[0]; oldv = xb[:, 0, 2].clone()
            newv = (oldv + torch.empty(B).uniform_(dlo, dhi)).clamp(clo, chi)
            mask = (torch.rand(B) < p).float()
            newv = mask * newv + (1 - mask) * oldv
            xb[:, :, 2] = newv.view(-1, 1)
            yb[:, 0] = yb[:, 0] + slope * (newv - oldv)
            xs = (xb - fmv) / fsv; ys = (yb - tmv) / tsv
            opt.zero_grad(set_to_none=True)
            loss = F.mse_loss(model(xs), ys)
            loss.backward(); opt.step()
        sched.step()
        if swa and e >= swa_start:
            sd = {k: v.detach().clone() for k, v in model.state_dict().items()}
            if swa_state is None:
                swa_state = sd; swa_n = 1
            else:
                swa_n += 1
                for k in swa_state:
                    if swa_state[k].dtype.is_floating_point:
                        swa_state[k] += (sd[k] - swa_state[k]) / swa_n
    if swa and swa_state is not None:
        model.load_state_dict(swa_state)
        model.train()
        wi
…[truncated]
output
New file created successfully at /app/final_train.py
Now let me check run4 progress.
Final training script is ready. Let me check the run-4 refinement results.
bash
sleep 230 && cat /tmp/run4.log 2>/dev/null
output
thr=63 nhard=80 nxhard=55 slope=-6.213e-05
local_p1           | HARD mean=0.2174 cd=0.3596 cl=0.0751 | XHARD mean=0.1635 cd=0.2519 cl=0.0752 nmae=0.0680
local_huber        | HARD mean=0.1253 cd=0.1990 cl=0.0516 | XHARD mean=0.1315 cd=0.2133 cl=0.0498 nmae=0.0602
Interesting , at threshold 63: - local_p1: HARD mean 0.217 (cd 0.360, cl 0.075); XHARD mean 0.163 (cd 0.252, cl 0.075) - local_huber: HARD mean 0.125 (cd 0.199, cl 0.052); XHARD mean 0.131 (cd 0.213, cl 0.050) Huber loss notably improved C_D and C_L on HARD (cd 0.360→0.199!) and a bit on XHARD (cd 0.252→0.213). Interesting. But wait , there's high variance. The local_p1 here (HARD cd 0.360) is much worse than at threshold 62 (HARD cd 0.277) and threshold 64 run2 (HARD cd 0.183). This is concerning variance across thresholds. The threshold-63 HARD region (vel 69-75, n=80) includes some particularly hard cases perhaps. Hmm, the variance is high. Note nhard=80 at thr63 with vel>=69; at thr62 nhard=95 with vel>=68. Different regions. The absolute numbers vary a lot by which cases fall in the bin and seed noise. This makes precise tuning noisy. Huber appears to help robustly (reduces sensitivity to C_D outliers). That makes sense: C_D has some high-drag outliers (max 0.046 vs mean 0.013), and squared loss on standardized C_D overweights them. Huber is more robust. Let me strongly consider Huber. Let me wait for the rest (swa, ep160, s0.85, jit003). Given the variance, I should base my final decision on consistency across all runs/thresholds rather than one number. So far: - local physics aug (p1, slope 1.0) robustly beats baseline on extrapolation across thresholds 62, 63, 64. - Huber seems to help. - slope 1.5 hurt; invariant slightly worse than physics on C_D. Let me get the remaining results.
Huber loss gives a notable, sensible improvement (C_D is right-skewed with high-drag outliers that squared error overweights). Note the cross-threshold variance is high, so I'll weight *consistency* over any single number. Let me see the rest.
bash
sleep 240 && cat /tmp/run4.log 2>/dev/null
output
thr=63 nhard=80 nxhard=55 slope=-6.213e-05
local_p1           | HARD mean=0.2174 cd=0.3596 cl=0.0751 | XHARD mean=0.1635 cd=0.2519 cl=0.0752 nmae=0.0680
local_huber        | HARD mean=0.1253 cd=0.1990 cl=0.0516 | XHARD mean=0.1315 cd=0.2133 cl=0.0498 nmae=0.0602
local_swa          | HARD mean=0.1586 cd=0.2491 cl=0.0681 | XHARD mean=0.1586 cd=0.2499 cl=0.0674 nmae=0.0783
- local_swa: HARD mean 0.159 (cd 0.249, cl 0.068); XHARD mean 0.159 (cd 0.250, cl 0.067). SWA helped vs local_p1 (HARD 0.217→0.159) on C_D. So SWA also helps (smooths, reduces variance). So far both Huber and SWA help over plain local_p1. Huber seems best on this threshold. Let me see ep160, s0.85, jit003. Given Huber's strong showing, I'll likely combine Huber + SWA for the final. Let me wait for remaining and then run a confirmation that combines Huber+SWA across 2 thresholds. Let me wait.
SWA also helps (smooths the trajectory, reduces variance). Both Huber and SWA improve over plain `local_p1`. Let me see the final three configs.
bash
sleep 240 && cat /tmp/run4.log 2>/dev/null
output
thr=63 nhard=80 nxhard=55 slope=-6.213e-05
local_p1           | HARD mean=0.2174 cd=0.3596 cl=0.0751 | XHARD mean=0.1635 cd=0.2519 cl=0.0752 nmae=0.0680
local_huber        | HARD mean=0.1253 cd=0.1990 cl=0.0516 | XHARD mean=0.1315 cd=0.2133 cl=0.0498 nmae=0.0602
local_swa          | HARD mean=0.1586 cd=0.2491 cl=0.0681 | XHARD mean=0.1586 cd=0.2499 cl=0.0674 nmae=0.0783
local_ep160        | HARD mean=0.1589 cd=0.2460 cl=0.0719 | XHARD mean=0.1411 cd=0.2086 cl=0.0737 nmae=0.0586
- local_ep160: HARD mean 0.159 (cd 0.246, cl 0.072); XHARD mean 0.141 (cd 0.209, cl 0.074). Longer training (160 ep) helped C_D vs local_p1 (100 ep). So more epochs helps. Both Huber, SWA, and more epochs help. Let me see s0.85 and jit003. Then I'll combine the best: Huber + SWA + more epochs. Let me wait. Actually, I'm spending a lot of time/tokens. Let me get the last two then do ONE confirmation run combining the winners (Huber + SWA + ep150) across two thresholds, then build the final model. Let me wait for the final two configs.
Longer training (160 epochs) also helps C_D. Let me get the last two configs, then I'll combine the winners (Huber + SWA + longer schedule).
bash
sleep 180 && cat /tmp/run4.log 2>/dev/null
output
thr=63 nhard=80 nxhard=55 slope=-6.213e-05
local_p1           | HARD mean=0.2174 cd=0.3596 cl=0.0751 | XHARD mean=0.1635 cd=0.2519 cl=0.0752 nmae=0.0680
local_huber        | HARD mean=0.1253 cd=0.1990 cl=0.0516 | XHARD mean=0.1315 cd=0.2133 cl=0.0498 nmae=0.0602
local_swa          | HARD mean=0.1586 cd=0.2491 cl=0.0681 | XHARD mean=0.1586 cd=0.2499 cl=0.0674 nmae=0.0783
local_ep160        | HARD mean=0.1589 cd=0.2460 cl=0.0719 | XHARD mean=0.1411 cd=0.2086 cl=0.0737 nmae=0.0586
local_s0.85        | HARD mean=0.2139 cd=0.3528 cl=0.0749 | XHARD mean=0.1590 cd=0.2433 cl=0.0748 nmae=0.0597
- local_s0.85: HARD mean 0.214 (cd 0.353), XHARD mean 0.159 (cd 0.243). Similar to local_p1 (slope 1.0). So slope 0.85 vs 1.0 ≈ same. slope 1.0 fine. Waiting for jit003 (last). But I have enough signal. Let me summarize run4 (threshold 63): - Baseline-ish local_p1: XHARD cd 0.252 - Huber: XHARD cd 0.213 ← best C_D - SWA: XHARD cd 0.250 - ep160: XHARD cd 0.209 ← best C_D - s0.85: XHARD cd 0.243 So Huber and ep160 are the strongest C_D improvers. Huber also improved C_L (0.050 vs 0.075). Strategy for final: combine Huber loss + longer epochs (150-160) + SWA. Let me verify this combination beats the individual ones and is robust across thresholds. Let me add Huber to the final train function and SWA (already there). Let me update final_train.py to use Huber loss (delta tuned). The Huber in exp.py used delta=0.01 in standardized space. Let me reconsider: the loss operates on standardized targets (std ~1). Huber delta=0.01 is VERY small , that's almost like L1 (MAE) for most errors (since most standardized errors > 0.01). So effectively it behaved like L1 loss! That's why it helped , L1/MAE is robust to the C_D outliers. Let me reconsider: delta=0.01 means the quadratic region is |diff|<0.01 std; nearly all errors are larger, so it's essentially MAE. So "Huber with delta 0.01" ≈ MAE. MAE on standardized targets. Interesting. MAE optimizes the median, robust to outliers. For NRMSE metric (which is RMSE-based), optimizing MAE isn't exactly aligned but the robustness helps generalization/extrapolation by not overfitting outliers. Hmm, but the metric is NRMSE (squared). Optimizing pure MAE might not be optimal for RMSE. But empirically it helped extrapolation a lot. There's a tradeoff: MAE reduces outlier influence → better typical-case extrapolation, but could have slightly worse RMSE if predictions are biased on outliers. Given the big improvement, the robustness wins here. Let me use a more balanced Huber delta so it's genuinely Huber (quadratic for small, linear for large) rather than pure MAE. Let me test a couple delta values in a confirmation run. Actually, let me reconsider , the improvement from "huber" (delta 0.01 ≈ MAE) was large. Let me test delta=0.01 (≈MAE), delta=0.25, delta=0.5, delta=1.0 (more MSE-like) to find the best for NRMSE. But time/tokens are a concern. Let me do ONE more confirmation run combining winners and testing a couple Huber deltas + SWA, at TWO thresholds (averaged) for robustness, then finalize. Let me design run5 (thresholds 62 and 64 to average out bin noise; 2 seeds each; eval XHARD = top ~55 velocities in each; epochs 150 + SWA): Configs: - A: mse_swa_ep150 (reference, no huber) - B: huber0.01_swa_ep150 (≈MAE + SWA) - C: huber0.3_swa_ep150 - D: huber0.6_swa_ep150 I'll compute combined XHARD metric across both thresholds (concatenate predictions? different models/thresholds , just average the two XHARD means). Let me implement run5 to loop over thresholds internally. Actually, simpler: evaluate each config at thr=62 and thr=64, report both XHARDs and their mean. Pick config with best average XHARD mean_nrmse and good balance. Let me make delta configurable in exp.py train_model (currently hardcoded 0.01). Let me update it to read cfg['huber_delta']. Let me update exp.py. Time: run5 = 4 configs × 2 thresholds × 2 seeds × (150 ep × 0.49s ≈ 74s) = 16 runs × 74s ≈ 20 min. That's a lot. Let me reduce: 2 seeds, but maybe 130 epochs, and maybe 3 configs. Let me do 3 Huber deltas vs MSE = 4 configs, 2 thresholds, 2 seeds, 130 epochs (~64s) → 16×64 = 17 min. I'll background and poll. Actually, let me cut to the essential question: delta for Huber. And confirm SWA+Huber+longer is robust. Let me do 4 configs at a SINGLE but "safer" evaluation: I'll evaluate on the union of high-velocity cases across multiple thresholds by just using threshold 62 (largest hard set, n~95 hard / 55 xhard) with 3 seeds, 150 epochs + SWA. That's 4×3×74 = 15 min. Hmm. Let me be economical: 4 configs, 2 seeds, th …[truncated]
Clear conclusions: **Huber/MAE-style loss and longer training + SWA each improve C_D extrapolation**; slope 0.85–1.0 are equivalent (1.0 is fine). Note the `huber` delta of 0.01 in standardized space is effectively MAE (robust to C_D's drag outliers). Let me make the Huber delta configurable and run a focused confirmation combining the winners (SWA + longer schedule) across Huber deltas.
bash
cd /app && sed -i "s/                d=0.01/                d=cfg.get('huber_delta',0.01)/" /tmp/exp.py && grep -n "huber_delta" /tmp/exp.py
output
84:                d=cfg.get('huber_delta',0.01)
bash
cd /app && cat > /tmp/run5.py << 'EOF'
import sys,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train'); v=pts[:,0,2]; thr=62.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
hardm=v[tem]>=68; xhardm=v[tem]>=71
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
results={}
def log(s): open('/tmp/run5.log','a').write(s+'\n')
def ev(name,cfg,seeds=(0,1,2)):
    H=[];X=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); H.append(metrics(pr[hardm],yte[hardm])); X.append(metrics(pr[xhardm],yte[xhardm]))
    h={k:float(np.mean([x[k] for x in H])) for k in H[0]}; xh={k:float(np.mean([x[k] for x in X])) for k in X[0]}
    results[name]={'hard':h,'xhard':xh}; json.dump(results,open('/tmp/run5_results.json','w'),indent=1)
    log('%-20s | HARD mean=%.4f cd=%.4f cl=%.4f | XHARD mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(
        name,h['mean_nrmse'],h['cd_nrmse'],h['cl_nrmse'],xh['mean_nrmse'],xh['cd_nrmse'],xh['cl_nrmse'],xh['cd_nmae']))
VA={'kind':'local','dlo':-8,'dhi':20,'p':1.0}
base={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'vel_aug':VA,'swa':True}
log('thr=62 nhard=%d nxhard=%d slope=%.3e'%(int(hardm.sum()),int(xhardm.sum()),slope))
ev('mse_swa',{**base})
ev('mae_swa',{**base,'loss':'huber','huber_delta':0.01})
ev('huber0.3_swa',{**base,'loss':'huber','huber_delta':0.3})
ev('huber0.6_swa',{**base,'loss':'huber','huber_delta':0.6})
log('DONE')
EOF
rm -f /tmp/run5.log /tmp/run5_results.json
nohup python3 /tmp/run5.py > /tmp/run5.stdout 2>&1 &
echo "started pid $!"
output
started pid 971
This is 4 configs × 3 seeds × ~74s (150 epochs + SWA with 3 BN refresh passes) ≈ 15 min. Let me poll in chunks. Let me wait ~290s and check. While waiting, let me reconsider the overall plan and whether there's risk in the approach. One concern: I've been evaluating on pseudo-extrapolation within the training velocity range (train < T, test in [T, 75]). The real test is [75, 82]. My final model trains on all velocities up to 75 and augments up to ~95 (dhi=20 from 75). The augmentation means the model is effectively trained (with fabricated C_D targets) on the 75-95 range. So the real test (75-82) is within the augmented training range. The quality there depends on: 1. How accurate the linear slope is for real C_D in 75-82. 2. Whether C_L truly stays flat. From physics and the regression, the linear slope is a good local approximation. The pseudo-experiments validate that this augmentation strategy extrapolates better than alternatives. I'm fairly confident. Another consideration: the magnitude of the slope for the FINAL model. estimate_cd_slope on all data (train+val). Let me make sure it's stable (~-6e-5). I'll print it during final training. Another thought: Should I also worry that at the real test, velocities could be even higher than 82 (the task says "beyond the inlet velocities present in training"; public_test is up to 82). The hidden test might be similar to public_test (75-82) or slightly beyond. dhi=20 from 75 covers up to 95, so even up to ~90 is covered. Good margin. Let me also consider: in the final model, I train on train+val (710 cases) with ceiling 75 (val max 74.16, train max 74.92). The augmentation pushes up. Good. Let me also plan to validate the final checkpoint by: 1. Loading it fresh (as the grader would), running on public_test, and sanity-checking predictions (C_D positive, reasonable magnitude ~0.01; C_L reasonable range). 2. Also check predictions vary sensibly with velocity (C_D decreasing). 3. Compare predictions to the in-distribution val targets if I train a variant on train-only... but final trains on train+val so can't validate on val. I'll do a separate sanity: train on train-only with final config, check val metrics (in-distribution) to ensure not broken, then train final on train+val for the deliverable. Let me wait for run5.
Confirmation run 5 (Huber-delta sweep with SWA + 150 epochs) is running. Let me verify my final-train script imports and runs a tiny smoke test in parallel to catch bugs early, without disturbing the experiment.
bash
cd /app && NT=2 python3 -c "
import sys; sys.path.insert(0,'/app')
import torch
torch.set_num_threads(2)
from final_train import train, estimate_cd_slope
from dataset import load_split
pts,tg=load_split('/app/data/train')
s=estimate_cd_slope(pts[:200], tg[:200,0]); print('slope(sample)=',round(s,7))
m,fm,fs,tm,ts,slope=train(pts[:120],tg[:120],epochs=3,swa=True,swa_frac=0.34,verbose=False)
print('smoke ok; slope=',round(slope,7),'fm len',len(fm),'tm',tm.tolist())
import torch
print('fwd check', m((pts[:4]-fm.view(1,1,-1))/fs.view(1,1,-1)).shape)
" 2>&1 | tail -6
output
slope(sample)= -5.78e-05
smoke ok; slope= -6.45e-05 fm len 4 tm [0.012679210864007473, 0.6363231539726257]
fwd check torch.Size([4, 2])
The final_train script works. Smoke test passes. Now let me wait for run5 results. Let me poll run5.
Smoke test passes , final-train script works end to end. Let me poll the Huber-delta confirmation.
bash
sleep 260 && cat /tmp/run5.log 2>/dev/null
output
thr=62 nhard=95 nxhard=55 slope=-6.265e-05
mse_swa              | HARD mean=0.1413 cd=0.2231 cl=0.0596 | XHARD mean=0.1472 cd=0.2353 cl=0.0591 nmae=0.0766
Only mse_swa done so far (3 seeds, slow). mse_swa: HARD mean 0.141 (cd 0.223, cl 0.060); XHARD mean 0.147 (cd 0.235, cl 0.059). Compared to earlier thr=62 local_p1 (no SWA, 100ep): XHARD cd 0.211. Hmm, mse_swa XHARD cd 0.235 is slightly worse than the earlier local_p1 (0.211) at thr62?? Variance. Earlier run3 local_p1_s1.0 at thr62: XHARD cd 0.211 (2 seeds). Now mse_swa thr62 (3 seeds, 150ep+SWA): XHARD cd 0.235. These differ due to seeds/epochs/SWA. Noise is significant. Let me wait for the Huber/MAE variants which showed the biggest gains. Let me wait more.
bash
sleep 280 && cat /tmp/run5.log 2>/dev/null
output
thr=62 nhard=95 nxhard=55 slope=-6.265e-05
mse_swa              | HARD mean=0.1413 cd=0.2231 cl=0.0596 | XHARD mean=0.1472 cd=0.2353 cl=0.0591 nmae=0.0766
mae_swa              | HARD mean=0.1296 cd=0.2043 cl=0.0550 | XHARD mean=0.1387 cd=0.2236 cl=0.0538 nmae=0.0726
mae_swa: HARD mean 0.130 (cd 0.204, cl 0.055); XHARD mean 0.139 (cd 0.224, cl 0.054). Better than mse_swa (HARD 0.141, XHARD 0.147) on both C_D and C_L. So MAE (huber 0.01) + SWA is better than MSE + SWA. Consistent with run4 where huber helped. Let me wait for huber0.3 and huber0.6.
MAE+SWA beats MSE+SWA on both targets (C_D 0.224 vs 0.235, C_L 0.054 vs 0.059) , consistent with run 4. Let me see the intermediate Huber deltas.
bash
sleep 250 && cat /tmp/run5.log 2>/dev/null
output
thr=62 nhard=95 nxhard=55 slope=-6.265e-05
mse_swa              | HARD mean=0.1413 cd=0.2231 cl=0.0596 | XHARD mean=0.1472 cd=0.2353 cl=0.0591 nmae=0.0766
mae_swa              | HARD mean=0.1296 cd=0.2043 cl=0.0550 | XHARD mean=0.1387 cd=0.2236 cl=0.0538 nmae=0.0726
huber0.3_swa         | HARD mean=0.1302 cd=0.2069 cl=0.0535 | XHARD mean=0.1423 cd=0.2309 cl=0.0537 nmae=0.0746
huber0.6_swa         | HARD mean=0.1336 cd=0.2126 cl=0.0547 | XHARD mean=0.1468 cd=0.2382 cl=0.0555 nmae=0.0770
DONE
Full run5 results (threshold 62, 3 seeds, 150ep + SWA): - mse_swa: HARD 0.141 (cd 0.223, cl 0.060); XHARD 0.147 (cd 0.235, cl 0.059) - mae_swa: HARD 0.130 (cd 0.204, cl 0.055); XHARD 0.139 (cd 0.224, cl 0.054) ← best - huber0.3_swa: HARD 0.130 (cd 0.207, cl 0.054); XHARD 0.142 (cd 0.231, cl 0.054) - huber0.6_swa: HARD 0.134 (cd 0.213, cl 0.055); XHARD 0.147 (cd 0.238, cl 0.056) So MAE (huber_delta 0.01) + SWA is the best overall, with the smallest delta performing best. As delta increases toward MSE, it gets worse. So pure MAE-like (small delta) is best. Decision for final config: - Local physics velocity augmentation: p=1.0, dlo=-8, dhi=20, slope=estimated (~-6.2e-5). - Loss: MAE (huber with small delta, effectively L1) on standardized targets. - SWA: yes (from 70% of training). - Epochs: 150. - bs=64, lr=1e-3, wd=1e-4, cosine schedule. This gives robust improvement over baseline across all thresholds tested (62, 63, 64). Let me do a final robustness check: confirm MAE+SWA+physics beats baseline at threshold 64 too (the original), and also check the in-distribution val performance when trained on train-only (to ensure I'm not catastrophically hurting in-distribution). Actually, let me prioritize and be time-efficient. I'm fairly confident. Let me do ONE combined check: 1. Train final config on train-only, eval on: - real val (in-distribution, vel 31-75) , sanity that in-dist isn't broken. - pseudo-extrapolation is already validated. Actually the real val is in-distribution so it's not the target regime, but I want to ensure the physics aug doesn't destroy in-distribution accuracy (in case the hidden test has some in-range cases, unlikely). Let me check val with baseline vs final-config (train-only) quickly. Let me also reconsider whether to use MAE vs a small-delta Huber. Pure MAE (L1) has non-smooth gradient at 0 but that's fine. The delta=0.01 Huber is essentially MAE but with a tiny quadratic region for very small errors (smoother near 0). I'll use delta=0.01 Huber (what I tested as "mae_swa"). Good. Now, one more important consideration: the final loss. The metric is NRMSE (RMSE-based, per target normalized by std). I'm training with MAE on standardized targets. MAE optimizes median, not mean. But empirically MAE gives better extrapolation (robustness to outliers dominates). However, I should double check that MAE doesn't introduce a systematic bias that hurts RMSE. The pseudo-extrapolation NRMSE (which IS the real metric) showed MAE best. So it's validated on the actual metric. Good. Now let me also decide: train final on train+val (710) vs train-only (630). Training on more in-distribution data should help the geometry/aoa mapping (which is the bulk of the signal for both C_D and C_L). The val is same distribution as train. More data → better. I'll use train+val for the final deliverable. The augmentation handles the velocity extrapolation regardless. But let me verify this choice doesn't hurt: more data generally helps. I'm confident. Let me reconsider SWA BN refresh: after averaging weights, I refresh BN stats with 3 passes using augmented velocities. This ensures BN running stats match the averaged weights and the augmented input distribution (which covers test). Good. Let me now: 1. Quick confirmation at threshold 64 of the final config vs baseline (2 seeds) + in-distribution val check. 2. Then build the final model on train+val and validate the checkpoint. Let me do the threshold-64 + val check efficiently. I'll write run6 that: - thr=64: train final config (train<64), eval XHARD (vel>=70) and HARD(>=68). - Also train final config on FULL train (630), eval on real val (in-distribution) → report val metrics. Compare to baseline on val. Actually, to save time, let me just do the val in-distribution check with the final config and baseline, train-only, plus reaffirm thr64. Let me limit to 2 seeds. Let me write run6. Actually, let me reconsider time budget: I've used ~72k tokens. I ha …[truncated]
**Final configuration locked in** (MAE + SWA + local physics augmentation is the consistent winner across thresholds 62/63/64): - Local velocity augmentation: p=1.0, Δvel ∈ [−8,+20], C_D shifted by estimated slope (~−6.2e-5), C_L held fixed - Loss: MAE (Huber δ=0.01) on standardized targets; SWA over the last 30%; 150 epochs Let me do a final robustness check: confirm at threshold 64 vs baseline, and verify in-distribution (real val) isn't harmed.
bash
cd /app && cat > /tmp/run6.py << 'EOF'
import sys,json; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train'); vpts,vtg=load('val'); v=pts[:,0,2]
def log(s): open('/tmp/run6.log','a').write(s+'\n'); 
# ---- (A) threshold 64 extrapolation confirm ----
thr=64.0; trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
xh=v[tem]>=70
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
VA={'kind':'local','dlo':-8,'dhi':20,'p':1.0}
final={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'vel_aug':VA,'swa':True,'loss':'huber','huber_delta':0.01}
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4}
def run(name,cfg,XtrI,YtrI,FM,FS,TM,TS,Xev,Yev,mask,seeds=(0,1)):
    R=[]
    for sd in seeds:
        m=train_model(XtrI,YtrI,cfg,FM,FS,TM,TS,seed=sd)
        pr=predict(m,Xev,FM,FS,TM,TS); R.append(metrics(pr[mask],Yev[mask]))
    a={k:float(np.mean([x[k] for x in R])) for k in R[0]}
    log('%-22s | mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(name,a['mean_nrmse'],a['cd_nrmse'],a['cl_nrmse'],a['cd_nmae']))
log('== thr64 XHARD(vel>=70, n=%d) slope=%.3e =='%(int(xh.sum()),slope))
run('final_extrap',final,xtr,ytr,fm,fs,tm,ts,xte,yte,xh)
run('baseline_extrap',base,xtr,ytr,fm,fs,tm,ts,xte,yte,xh)
# ---- (B) in-distribution: train on full train, eval on real val ----
fmF,fsF=standardize_stats(pts); tmF=tg.mean(0); tsF=tg.std(0).clamp_min(1e-8)
slopeF=estimate_cd_slope(pts,tg[:,0])
finalF={**final,'cd_slope':slopeF}
allmask=torch.ones(vtg.shape[0],dtype=torch.bool)
log('== in-distribution real val (n=%d) slope=%.3e =='%(vtg.shape[0],slopeF))
run('final_val',finalF,pts,tg,fmF,fsF,tmF,tsF,vpts,vtg,allmask)
run('baseline_val',base,pts,tg,fmF,fsF,tmF,tsF,vpts,vtg,allmask)
log('DONE')
EOF
rm -f /tmp/run6.log
nohup python3 /tmp/run6.py > /tmp/run6.stdout 2>&1 &
echo "started pid $!"
output
started pid 1088
This is 4 named runs × 2 seeds = 8 trainings, mix of 150ep (final) and 100ep (baseline). ~ (4×150 + 4×100)×0.49 ≈ 490s ≈ 8 min. Let me wait. While waiting, let me reconsider one subtle point about the evaluation and my loss choice. The grader reads de-standardized predictions. My targ_mean/targ_std are computed from the training targets (raw). Predictions = model_output * targ_std + targ_mean. Since I train the model to output standardized targets via MAE, this is consistent. Also, I should double-check: my final model uses SWA weight averaging. After averaging, BN stats refreshed with augmented inputs. At inference, the grader just does forward in eval mode → uses BN running stats. Good. Let me also think about whether there's any risk the grader applies standardization differently (e.g., expects feat_std to not be clamped). No, standard. Let me wait for run6. Let me reconsider: Is MAE the best choice given the metric is NRMSE (squared)? The pseudo-extrapolation results consistently show MAE-ish (small huber delta) beats MSE on the NRMSE metric itself in the extrapolation regime. This is because MSE overfits to the high-drag outlier cases during training, which don't generalize well to the extrapolation regime, whereas MAE learns a more robust central relationship. So for the extrapolation target, MAE wins on NRMSE. Good, validated. Let me wait.
Robustness check running (threshold-64 extrapolation + in-distribution val). Let me reflect while it runs: my loss choice (MAE) was validated *on the actual NRMSE metric* in the extrapolation regime , MSE overfits C_D's high-drag outliers which don't transfer past the training ceiling. Let me check results.
bash
sleep 290 && cat /tmp/run6.log 2>/dev/null
output
== thr64 XHARD(vel>=70, n=70) slope=-6.165e-05 ==
final_extrap           | mean=0.1187 cd=0.1892 cl=0.0482 nmae=0.0630
baseline_extrap        | mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
At threshold 64, XHARD (vel>=70, the true extrapolation region): - final_extrap: mean 0.119 (cd 0.189, cl 0.048, nmae 0.063) - baseline_extrap: mean 0.183 (cd 0.226, cl 0.139, nmae 0.066) The final config beats baseline on ALL metrics: mean 0.119 vs 0.183 (35% better), cd 0.189 vs 0.226, cl 0.048 vs 0.139, nmae 0.063 vs 0.066. Now waiting for the in-distribution val check.
Excellent , at threshold 64, the final config beats baseline on **every** metric in the extrapolation region: mean 0.119 vs 0.183 (35% better), C_D 0.189 vs 0.226, C_L 0.048 vs 0.139. Let me confirm it doesn't hurt in-distribution performance.
bash
sleep 150 && cat /tmp/run6.log 2>/dev/null
output
== thr64 XHARD(vel>=70, n=70) slope=-6.165e-05 ==
final_extrap           | mean=0.1187 cd=0.1892 cl=0.0482 nmae=0.0630
baseline_extrap        | mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
The in-distribution val runs are still going (they train on full 630 data, 150 epochs for final). Let me wait more.
bash
sleep 180 && cat /tmp/run6.log 2>/dev/null
output
== thr64 XHARD(vel>=70, n=70) slope=-6.165e-05 ==
final_extrap           | mean=0.1187 cd=0.1892 cl=0.0482 nmae=0.0630
baseline_extrap        | mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
bash
sleep 120 && cat /tmp/run6.log 2>/dev/null; echo '--- stdout ---'; tail -3 /tmp/run6.stdout
output
== thr64 XHARD(vel>=70, n=70) slope=-6.165e-05 ==
final_extrap           | mean=0.1187 cd=0.1892 cl=0.0482 nmae=0.0630
baseline_extrap        | mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
--- stdout ---
    aoa=pts[:,0,3].numpy(); vel=pts[:,0,2].numpy(); cd=ytr[:,0].numpy()
                                                       ~~~^^^^^
IndexError: too many indices for tensor of dimension 1
There's a bug in the in-distribution part: I called estimate_cd_slope(pts, tg[:,0]) but estimate_cd_slope expects (xtr, ytr) where ytr is 2D (it does ytr[:,0]). I passed tg[:,0] as ytr, which is 1D. Let me fix: pass tg (2D) instead of tg[:,0]. In run6 I wrote `slopeF=estimate_cd_slope(pts,tg[:,0])`. The function signature is estimate_cd_slope(xtr,ytr) and internally does ytr[:,0]. So I should pass tg. Let me fix and rerun just the in-distribution part. The extrapolation part (A) already succeeded and is the key result. The in-distribution check is just a sanity. Let me fix and rerun part B quickly. Note: in final_train.py, estimate_cd_slope has signature estimate_cd_slope(points, cd) where cd is 1D (it does cd.numpy()). That's the CORRECT one for final_train. But in exp.py, estimate_cd_slope(xtr,ytr) does ytr[:,0]. Different signatures! In run6 I imported from exp, so it expects ytr 2D. I passed tg[:,0]. Let me fix run6 to pass tg. Let me just rerun part B with the fix.
A harmless bug in the sanity-check portion (wrong arg shape for the `exp.py` slope helper). The key extrapolation result already succeeded. Let me fix and rerun just the in-distribution check.
bash
cd /app && cat > /tmp/run6b.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train'); vpts,vtg=load('val')
def log(s): open('/tmp/run6.log','a').write(s+'\n')
fmF,fsF=standardize_stats(pts); tmF=tg.mean(0); tsF=tg.std(0).clamp_min(1e-8)
slopeF=estimate_cd_slope(pts,tg)  # fixed: pass 2D targets
VA={'kind':'local','dlo':-8,'dhi':20,'p':1.0}
final={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slopeF,'vel_aug':VA,'swa':True,'loss':'huber','huber_delta':0.01}
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4}
am=torch.ones(vtg.shape[0],dtype=torch.bool)
def run(name,cfg,seeds=(0,1)):
    R=[]
    for sd in seeds:
        m=train_model(pts,tg,cfg,fmF,fsF,tmF,tsF,seed=sd)
        pr=predict(m,vpts,fmF,fsF,tmF,tsF); R.append(metrics(pr,vtg))
    a={k:float(np.mean([x[k] for x in R])) for k in R[0]}
    log('%-22s | mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(name,a['mean_nrmse'],a['cd_nrmse'],a['cl_nrmse'],a['cd_nmae']))
log('== in-distribution real val (n=%d) slope=%.3e =='%(vtg.shape[0],slopeF))
run('final_val',final); run('baseline_val',base)
log('DONE-B')
EOF
nohup python3 /tmp/run6b.py > /tmp/run6b.stdout 2>&1 &
echo "started pid $!"
output
started pid 1173
While that runs, let me start building the actual final model so I don't waste time. Actually, let me wait for the in-distribution sanity first to be sure. It's ~4 trainings (2 final @150ep + 2 baseline @100ep) ≈ 5 min. Let me wait. Actually, let me reconsider the in-distribution concern. If physics aug hurts in-distribution val a lot, that might matter IF the hidden test has some in-range cases. But public_test is entirely 75-82 (out of range), strongly implying the hidden test is too. So even if in-distribution degrades somewhat, the extrapolation gain dominates. Still, good to check it's not catastrophic. Let me wait ~200s. Meanwhile, let me reconsider whether to train the final on train+val or train-only. Given the hidden test is extrapolation, and val provides more geometry/aoa coverage, train+val is better. I'll use train+val. Let me also reconsider seeds: for the final single checkpoint, I'll pick seed 0 but with SWA (which averages along trajectory, reducing seed variance). Good enough. I could also consider training a few seeds and picking the one with best val... but val is in-distribution, not the target regime, so selecting on val might not help extrapolation. I'll just use a fixed seed with SWA. Actually , a thought: could I reduce variance further by training multiple seeds and averaging their de-standardized PREDICTIONS? No , the grader loads ONE state_dict and runs the model itself. I can't ensemble predictions. Weight-averaging across independent seeds (different random inits) generally fails because they're in different loss basins; averaging their weights gives a bad model. SWA works only along a single trajectory. So I stick with single-seed + SWA. Let me wait for run6b.
While the in-distribution sanity check runs, let me wait for it , this confirms the physics augmentation doesn't wreck in-range accuracy (important only if the hidden test has any in-range cases).
bash
sleep 260 && cat /tmp/run6.log 2>/dev/null
output
== thr64 XHARD(vel>=70, n=70) slope=-6.165e-05 ==
final_extrap           | mean=0.1187 cd=0.1892 cl=0.0482 nmae=0.0630
baseline_extrap        | mean=0.1827 cd=0.2264 cl=0.1390 nmae=0.0662
== in-distribution real val (n=80) slope=-5.819e-05 ==
final_val              | mean=0.0804 cd=0.1309 cl=0.0298 nmae=0.0298
In-distribution real val (n=80): - final_val: mean 0.080 (cd 0.131, cl 0.030, nmae 0.030) Waiting for baseline_val. But already, final_val in-distribution mean 0.080 is quite good (cd 0.131, cl 0.030). The physics aug does NOT wreck in-distribution , in fact it's quite good. Let me see baseline_val for comparison. Note slope on full train = -5.82e-5 (slightly different from train+val; fine). Let me wait for baseline_val.
In-distribution val for the final config is strong (mean 0.080, C_D 0.131, C_L 0.030) , so the physics augmentation does *not* harm in-range accuracy. Let me get the baseline comparison.
bash
sleep 90 && cat /tmp/run6.log 2>/dev/null | tail -3
output
final_val              | mean=0.0804 cd=0.1309 cl=0.0298 nmae=0.0298
baseline_val           | mean=0.0968 cd=0.1513 cl=0.0423 nmae=0.0277
DONE-B
In-distribution real val: - final_val: mean 0.080 (cd 0.131, cl 0.030, nmae 0.030) - baseline_val: mean 0.097 (cd 0.151, cl 0.042, nmae 0.028) So the final config BEATS baseline even in-distribution (mean 0.080 vs 0.097)! C_D 0.131 vs 0.151, C_L 0.030 vs 0.042. Only cd_nmae is very slightly worse (0.030 vs 0.028), negligible. This is great , the final config (MAE + SWA + physics aug) is better both in-distribution AND in extrapolation. The MAE loss + SWA improve generalization overall, and the physics aug helps C_L decorrelate from velocity (better even in-distribution val, since val velocities near the top of range benefit). So my final config is robustly better everywhere. Now let me build the FINAL deliverable: - Train on train+val (710 cases) with the final config. - Use seed 0 + SWA. - Save to /app/outputs/model.pt. final_train.py already does this (train+val, seed 0, the chosen hyperparameters). Let me double-check final_train.py's defaults match the validated config: - epochs=150 ✓ - bs=64 ✓ - lr=1e-3, wd=1e-4 ✓ - dlo=-8, dhi=20, p=1.0 ✓ - clo=28, chi=98 ✓ (clamp range; chi=98 covers augmented up to 95) - swa=True, swa_frac=0.7 ✓ - slope=None → estimated from data ✓ - BUT: final_train.py uses F.mse_loss! I need to change it to MAE (huber delta 0.01). Let me check. Yes, final_train.py currently has `loss = F.mse_loss(model(xs), ys)`. I need to change to MAE/Huber. Let me update to use smooth_l1 / L1. I'll use L1 loss (MAE) which matches "huber delta 0.01 ≈ MAE". Actually, let me use Huber with delta 0.01 to exactly match what I validated, or just L1. The validated "mae_swa" used huber_delta=0.01 in exp.py, which computes: where(|diff|<0.01, 0.5*diff^2/0.01, |diff|-0.5*0.01). This is Huber with delta 0.01. For |diff|>0.01 it's |diff| - 0.005, i.e., MAE shifted by constant (gradient = sign). For |diff|<0.01, quadratic. This is essentially MAE with a tiny smooth region. F.smooth_l1_loss with beta=0.01 is exactly this Huber form: for |x|<beta: 0.5*x^2/beta; else |x|-0.5*beta. Yes! torch.nn.functional.smooth_l1_loss(pred, target, beta=0.01) matches exactly. Let me use that. Let me update final_train.py. Also, I should double check the SWA BN refresh in final_train.py uses augmented velocities (it does , it perturbs velocity in the refresh loop). Good. Let me update the loss in final_train.py.
The final config **beats baseline in-distribution too** (val mean 0.080 vs 0.097), so it's strictly better everywhere. Now I must fix one thing in `final_train.py`: it still uses MSE, but my validated winner uses MAE (Huber δ=0.01, exactly `smooth_l1_loss` with beta=0.01). Let me update it.
str_replace_based_edit_tool
command: str_replace
path: /app/final_train.py
old_str:             xs = (xb - fmv) / fsv; ys = (yb - tmv) / tsv
            opt.zero_grad(set_to_none=True)
            loss = F.mse_loss(model(xs), ys)
            loss.backward(); opt.step()
new_str:             xs = (xb - fmv) / fsv; ys = (yb - tmv) / tsv
            opt.zero_grad(set_to_none=True)
            # MAE-like (Huber with tiny beta) on standardized targets: robust to
            # C_D's right-skewed high-drag outliers, which improves extrapolation.
            loss = F.smooth_l1_loss(model(xs), ys, beta=0.01)
            loss.backward(); opt.step()
output
The file /app/final_train.py has been edited successfully.
Now let me also double-check the estimate_cd_slope in final_train.py works with the 2D targets... no, its signature is estimate_cd_slope(points, cd) where cd is targets[:,0] (1D). In train(), it calls `slope = estimate_cd_slope(points, targets[:, 0])`. And inside it does `cdn = cd.numpy()`. So cd is 1D → cd.numpy() works. Good. That's the correct usage in final_train.py (different from the exp.py version). Let me verify by running the final training now. It trains on train+val (710), 150 epochs + SWA. Time: 710 samples → ~0.73s/epoch? Let me estimate: 468 samples was 0.49s/epoch at bs64. 710 samples → ~0.74s/epoch. 150 epochs + SWA BN refresh (3 passes over data ≈ negligible). So ~150×0.74 ≈ 111s + overhead ≈ 2 min. Plus slope estimation (loops over 710 samples with 12 bins) ~ a few seconds. Fine. Let me run it in the background and monitor. Actually, let me run it directly (should be ~2-3 min, under 300s). But to be safe with the 300s tool limit, let me background it and poll. Let me launch final_train.py.
`final_train.py` now matches the validated winner exactly. Let me generate the final checkpoint, training on train+val (710 cases).
bash
cd /app && rm -f outputs/model.pt && NT=8 SEED=0 nohup python3 final_train.py > /tmp/final.log 2>&1 &
echo "started pid $!"
output
started pid 1253
bash
sleep 150 && cat /tmp/final.log 2>/dev/null; echo '---'; ls -la /app/outputs/ 2>/dev/null
output
[final] training on 710 cases (train+val)
[final] slope=-5.907e-05 feat_mean=[0.38364875316619873, 0.007897475734353065, 53.19941711425781, 0.07678442448377609] targ_mean=[0.012753964401781559, 0.6618618965148926]
[final] wrote /app/outputs/model.pt
---
total 347
drwxr-sr-x 2 h2tagent h2tagent   4096 Jun 19 23:02 .
drwxrws--- 5 h2tagent h2tagent   4096 Jun 19 23:02 ..
-rw-r--r-- 1 h2tagent h2tagent 346611 Jun 19 23:02 model.pt
The final model is saved. slope=-5.907e-5 (on train+val). feat_mean velocity=53.2, targ_mean=[0.0128, 0.662]. Now let me validate the checkpoint thoroughly by simulating EXACTLY what the grader does: 1. Load model.pt with weights_only=True. 2. build_model(cfg), load_state_dict. 3. Standardize public_test points with feat_mean/feat_std. 4. Forward → de-standardize with targ_mean/targ_std. 5. Check predictions are sane: C_D positive ~0.01, C_L reasonable range, C_D decreasing with velocity. Let me also verify the state_dict keys match exactly (strict load). Let me write a verification script mimicking the grader.
The checkpoint is written. Now let me rigorously verify it loads and runs **exactly as the grader would** , strict `state_dict` load into a fresh model, the standardize→forward→de-standardize pipeline, and sanity of predictions on `public_test`.
bash
cd /app && python3 -c "
import json,torch,sys; sys.path.insert(0,'/app')
from candidate_model import build_model
cfg=json.load(open('task_config.json'))
ck=torch.load('outputs/model.pt',weights_only=True)
print('keys:',sorted(ck.keys()))
for k in ['feat_mean','feat_std','targ_mean','targ_std']:
    t=ck[k]; print(f'  {k}: shape={tuple(t.shape)} dtype={t.dtype} vals={[round(x,5) for x in t.tolist()]}')
# strict load into fresh model
m=build_model(cfg)
missing=m.load_state_dict(ck['state_dict'],strict=True)
print('load_state_dict strict OK:',missing)
m.eval()
# grader-style inference on public_test
pts=torch.load('data/public_test/split.pt',weights_only=True)['points'].float()
fm=ck['feat_mean'].view(1,1,-1); fs=ck['feat_std'].view(1,1,-1)
with torch.no_grad():
    out=m((pts-fm)/fs)
pred=out*ck['targ_std'].view(1,-1)+ck['targ_mean'].view(1,-1)
cd,cl=pred[:,0],pred[:,1]
print()
print('public_test predictions:')
print('  C_D: min=%.5f max=%.5f mean=%.5f  (train C_D mean ~0.0128)'%(cd.min(),cd.max(),cd.mean()))
print('  C_L: min=%.4f max=%.4f mean=%.4f   (train C_L mean ~0.66)'%(cl.min(),cl.max(),cl.mean()))
print('  any NaN:',torch.isnan(pred).any().item(),' any negative C_D:',(cd<0).any().item())
"
output
keys: ['feat_mean', 'feat_std', 'state_dict', 'targ_mean', 'targ_std']
  feat_mean: shape=(4,) dtype=torch.float32 vals=[0.38365, 0.0079, 53.19942, 0.07678]
  feat_std: shape=(4,) dtype=torch.float32 vals=[0.3956, 0.03333, 12.65285, 0.09548]
  targ_mean: shape=(2,) dtype=torch.float32 vals=[0.01275, 0.66186]
  targ_std: shape=(2,) dtype=torch.float32 vals=[0.00513, 0.57827]
load_state_dict strict OK: <All keys matched successfully>

public_test predictions:
  C_D: min=0.00654 max=0.02698 mean=0.01151  (train C_D mean ~0.0128)
  C_L: min=-0.5589 max=1.7326 mean=0.6467   (train C_L mean ~0.66)
  any NaN: False  any negative C_D: False
The checkpoint: - Has all 4 normalization tensors (correct shapes/dtypes). - state_dict loads strictly into the fixed architecture. - Predictions on public_test are sane: C_D in [0.0065, 0.027], mean 0.0115 (slightly below train mean 0.0128, consistent with higher velocity → lower drag, which is the physical effect!). C_L in [-0.56, 1.73], mean 0.647 (similar to train 0.66, consistent with velocity-independence). No NaNs, no negative C_D. The fact that C_D mean on public_test (0.0115) is lower than train mean (0.0128) is exactly the physically expected Reynolds drag reduction at higher velocity , the model is extrapolating the trend correctly! Let me do one more sanity check: verify that the model's C_D predictions DECREASE with velocity (the physics) and C_L is roughly velocity-invariant, by probing a fixed airfoil at varying velocities. This confirms the learned extrapolation behaves physically. Let me take a few public_test cases and sweep the velocity input, checking C_D decreases and C_L ~flat.
The checkpoint is valid: all four tensors present with correct shapes, strict `state_dict` load succeeds, and predictions are physically sane with no NaNs. Notably, the mean predicted C_D on `public_test` (0.0115) is **below** the training mean (0.0128) , exactly the Reynolds drag-reduction the model should extrapolate at higher velocity. Let me confirm the learned behavior is physical by sweeping velocity on fixed airfoils.
bash
cd /app && python3 -c "
import json,torch,sys; sys.path.insert(0,'/app')
from candidate_model import build_model
cfg=json.load(open('task_config.json'))
ck=torch.load('outputs/model.pt',weights_only=True)
m=build_model(cfg); m.load_state_dict(ck['state_dict']); m.eval()
fm=ck['feat_mean'].view(1,1,-1); fs=ck['feat_std'].view(1,1,-1)
tm=ck['targ_mean'].view(1,-1); ts=ck['targ_std'].view(1,-1)
pts=torch.load('data/public_test/split.pt',weights_only=True)['points'].float()
# take 5 cases, sweep velocity 40..90, report C_D and C_L
import numpy as np
idx=[0,10,20,30,40]
vels=[40,55,70,75,80,85]
print('velocity sweep (C_D / C_L) per case:')
for i in idx:
    base=pts[i:i+1].clone()
    row=[]
    for v in vels:
        b=base.clone(); b[:,:,2]=float(v)
        with torch.no_grad(): o=m((b-fm)/fs)*ts+tm
        row.append((o[0,0].item(),o[0,1].item()))
    cds=' '.join('%.4f'%r[0] for r in row)
    cls=' '.join('%+.3f'%r[1] for r in row)
    print(f'  case{i:2d}: vels={vels}')
    print(f'          C_D= {cds}')
    print(f'          C_L= {cls}')
"
output
velocity sweep (C_D / C_L) per case:
  case 0: vels=[40, 55, 70, 75, 80, 85]
          C_D= 0.0108 0.0101 0.0095 0.0093 0.0091 0.0089
          C_L= +0.842 +0.852 +0.875 +0.875 +0.871 +0.866
  case10: vels=[40, 55, 70, 75, 80, 85]
          C_D= 0.0194 0.0184 0.0174 0.0171 0.0168 0.0165
          C_L= +1.317 +1.336 +1.356 +1.367 +1.375 +1.378
  case20: vels=[40, 55, 70, 75, 80, 85]
          C_D= 0.0158 0.0148 0.0139 0.0137 0.0135 0.0132
          C_L= +1.214 +1.219 +1.242 +1.253 +1.261 +1.260
  case30: vels=[40, 55, 70, 75, 80, 85]
          C_D= 0.0086 0.0080 0.0075 0.0073 0.0071 0.0069
          C_L= +0.026 +0.034 +0.035 +0.031 +0.025 +0.019
  case40: vels=[40, 55, 70, 75, 80, 85]
          C_D= 0.0252 0.0241 0.0226 0.0220 0.0214 0.0209
          C_L= +1.673 +1.700 +1.727 +1.732 +1.732 +1.729
The velocity sweep confirms the model behaves physically: - **C_D monotonically decreases** with velocity across all cases (e.g., case0: 0.0108 → 0.0089 as velocity goes 40→85). This is the correct Reynolds drag reduction, and it extends smoothly into the extrapolation region (75-85). - **C_L is nearly flat** with velocity (e.g., case0: 0.842 → 0.866, tiny variation; case30: ~0.02-0.035). Velocity-invariant, as desired. The extrapolation to 80-85 is smooth and monotonic , no blow-up. This is exactly the behavior I engineered. The model is working as intended. The slope of C_D vs velocity: case0 from 40→85 (45 m/s) drops ~0.0019, i.e., ~-4.2e-5/m/s. The imposed slope was -5.9e-5 but the model blends its learned relation with the augmentation, giving a sensible net slope. Good. Now, let me reconsider whether there are any further improvements worth making given my remaining budget, or whether to finalize. Current final model validated: - Extrapolation (pseudo thr64 XHARD): mean 0.119 vs baseline 0.183. - In-distribution val: mean 0.080 vs baseline 0.097. - Physical behavior confirmed. Potential further improvements to consider: 1. **Slightly stronger/better slope modeling** , I found slope 1.0x best; 1.5x worse. Current is fine. 2. **dhi (upward augmentation range)** , dhi=20 (up to 95 from 75). Could try dhi=25 for more margin, but dhi30 was marginally worse. Keep 20. 3. **More seeds / deeper SWA** , SWA already reduces variance. Could train longer (200 epochs). Marginal. 4. **Per-sample slope** (proportional to drag level) , more complex, risk. Skip. I think the model is solid. But let me reconsider one thing: the final model uses seed 0. Given SWA, variance is low, but let me verify the final model's quality isn't a bad-seed outlier by checking its in-distribution val metric directly (train+val training means I can't use val as held-out... the final model was trained on val too). Hmm, I can't validate the EXACT final model (trained on train+val) on val since val is in its training set. But I validated the CONFIG extensively via pseudo-splits and train-only→val. The config is robust. The final model just applies it to train+val. SWA reduces seed sensitivity. To be safe against a bad seed, I could train 2-3 seeds and pick the best by... but I have no held-out extrapolation set for the final (all data used). I could hold out a small high-velocity slice of train+val as a final selection set. But that reduces training data and the selection signal is noisy. Given SWA's stability and the extensive validation, I'll trust seed 0. Actually, let me reconsider: maybe I should NOT train on val, so I can use val as a final sanity gate on the actual deliverable model. But val is in-distribution (not extrapolation), so it's a weak gate. The benefit of more data (val is only 80 cases, ~11% more) is modest. Trade-off: Option A: train on train+val (710), no final gate. More data. Option B: train on train (630), gate on val (in-distribution sanity). Given val is small and in-distribution, the extra data (Option A) is probably slightly better for the geometry/aoa mapping, and I've already confirmed the config generalizes. I'll keep Option A (train+val) but let me ADD a lightweight safeguard: train a couple of seeds on train+val and, lacking a held-out extrapolation set, select the seed whose predicted behavior is most physically consistent and whose public_test prediction distribution is most reasonable. Actually that's hand-wavy. Better safeguard: Let me verify seed robustness by training seed 1 and seed 2 versions with the final config on train+val, and compare their public_test prediction distributions and a pseudo-extrapolation metric. But I can't compute a metric on public_test (no labels). Alternative: I'll assess seed stability using the pseudo-split once more: train final config (train<75 all, i.e., full minus top) ... Let me do a clean final robustness: hold out top-velocity cases of train+val as a final extrapolation …[truncated]
The velocity sweep confirms the learned physics is correct and extrapolates smoothly: **C_D decreases monotonically with velocity** (Reynolds drag reduction) into the 75–85 range with no blow-up, while **C_L stays essentially flat** (velocity-invariant). Exactly the engineered behavior. Let me run one final stability/expectation check: a pseudo-split on train+val (hold out vel≥69.5, mirroring the real ceiling→test gap) across 3 seeds, to quantify seed variance and the expected extrapolation score.
bash
cd /app && cat > /tmp/run7.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
ptr,ttr=load('train'); pva,tva=load('val')
pts=torch.cat([ptr,pva],0); tg=torch.cat([ttr,tva],0)
v=pts[:,0,2]; thr=69.5
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
def log(s): open('/tmp/run7.log','a').write(s+'\n')
VA={'kind':'local','dlo':-8,'dhi':20,'p':1.0}
final={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'vel_aug':VA,'swa':True,'loss':'huber','huber_delta':0.01}
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4}
log('train+val pseudo: ntrain=%d ntest(vel>=%.1f)=%d slope=%.3e'%(xtr.shape[0],thr,xte.shape[0],slope))
def run(name,cfg,seeds):
    res=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); res.append(metrics(pr,yte))
    arr={k:np.array([r[k] for r in res]) for k in res[0]}
    log('%-14s seeds=%s mean_nrmse=%.4f+-%.4f cd=%.4f cl=%.4f nmae=%.4f'%(
        name,list(seeds),arr['mean_nrmse'].mean(),arr['mean_nrmse'].std(),
        arr['cd_nrmse'].mean(),arr['cl_nrmse'].mean(),arr['cd_nmae'].mean()))
run('final',final,(0,1,2))
run('baseline',base,(0,1,2))
log('DONE')
EOF
rm -f /tmp/run7.log
nohup python3 /tmp/run7.py > /tmp/run7.stdout 2>&1 &
echo "started pid $!"
output
started pid 1571
This trains 3 seeds of final (150ep) + 3 seeds baseline (100ep) on ~620 train samples. Time ~ (3×150 + 3×100)×0.73s ≈ 550s ≈ 9 min. Let me wait in chunks. While waiting, let me reconsider the deliverable is complete and correct. The model.pt is saved and validated. This run7 is just confirmation; the deliverable won't change unless run7 reveals a problem. Let me also write up documentation/notes. But first let me wait for run7. Let me reconsider the robustness of my slope sign and the possibility that the hidden test extrapolates even further (e.g., velocity > 82). My augmentation covers up to 95, and the sweep showed smooth monotonic behavior up to 85. Even at 90-95 it should be fine (trained there). Good. Let me wait for run7.
Final confirmation run is training (3 seeds each of final vs baseline on a train+val pseudo-split). Let me wait for it.
bash
sleep 290 && cat /tmp/run7.log 2>/dev/null
output
train+val pseudo: ntrain=629 ntest(vel>=69.5)=81 slope=-6.515e-05
final          seeds=[0, 1, 2] mean_nrmse=0.1083+-0.0032 cd=0.1770 cl=0.0396 nmae=0.0597
final (3 seeds) on train+val pseudo-extrapolation (test vel>=69.5, n=81): - mean_nrmse = 0.108 ± 0.003 (very low seed variance!), cd=0.177, cl=0.040, nmae=0.060. Seed variance is tiny (±0.003), confirming SWA stabilizes and seed 0 is reliable. Let me wait for baseline comparison. This pseudo-split (ceiling 69.5, test 69.5-75) is the closest analog to the real scenario (ceiling 75, test 75-82). Expected real mean_nrmse ~0.10-0.12 for the final model. Let me get baseline.
Very low seed variance (mean_nrmse 0.108 ± 0.003) , SWA makes seed 0 reliable. This train+val pseudo-split (ceiling 69.5) is the closest analog to the real ceiling-75→test scenario. Let me get the baseline comparison.
bash
sleep 150 && cat /tmp/run7.log 2>/dev/null
output
train+val pseudo: ntrain=629 ntest(vel>=69.5)=81 slope=-6.515e-05
final          seeds=[0, 1, 2] mean_nrmse=0.1083+-0.0032 cd=0.1770 cl=0.0396 nmae=0.0597
baseline       seeds=[0, 1, 2] mean_nrmse=0.1003+-0.0118 cd=0.1243 cl=0.0763 nmae=0.0273
DONE
Interesting! On this particular pseudo-split (ceiling 69.5, test 69.5-75): - final: mean 0.108 ± 0.003, cd 0.177, cl 0.040, nmae 0.060 - baseline: mean 0.100 ± 0.012, cd 0.124, cl 0.076, nmae 0.027 Here baseline has LOWER mean_nrmse (0.100 vs 0.108) and much lower C_D (0.124 vs 0.177) and nmae (0.027 vs 0.060), but WORSE C_L (0.076 vs 0.040). Higher variance though (±0.012 vs ±0.003). Wait, this contradicts the earlier thresholds (62, 63, 64) where final beat baseline on C_D! Why is baseline's C_D better here? The difference: this pseudo-split has ceiling 69.5, so test region is 69.5-75, which is only 0-5.5 m/s beyond the ceiling , a SHORTER extrapolation than thresholds 62-64 (which tested 6-13 beyond). With a shorter extrapolation, the baseline's learned C_D relation still interpolates/extrapolates well (it's close to the training ceiling), so baseline C_D is good. The physics aug's global linear slope is slightly cruder for C_D in this near-ceiling region, hence final C_D (0.177) worse than baseline (0.124) here. BUT: the real test is 75-82, i.e., 0-7 beyond ceiling 75. This is between the "near" (0-5.5) regime of run7 and the "far" (6-13) regime of runs 2-4. So reality is somewhere in between. Hmm, this is a nuanced situation. Let me think carefully: - For SHORT extrapolation (0-5 beyond): baseline C_D is better (its learned relation still valid); final C_D slightly worse (crude global slope). But baseline C_L much worse. - For LONGER extrapolation (6-13 beyond): final C_D better (baseline's relation breaks down); final C_L much better. The real test (0-7 beyond, centered ~3-7): likely final C_L is much better, and C_D is roughly comparable (maybe baseline slightly better at the near end, final better at the far end 80-82). The KEY question for the overall metric (mean_nrmse over C_D and C_L): - final: cl gain is large (0.040 vs 0.076, i.e., -0.036) but cd loss (0.177 vs 0.124, +0.053) in THIS near split. - In the far splits, final wins both. So on average over the real test range (0-7 beyond), the C_L gain (robust, ~half) likely outweighs, but the C_D could go either way. Wait, let me reconsider. The mean_nrmse weights C_D and C_L equally. In run7 (near): final mean 0.108 vs baseline 0.100 , baseline slightly better. In thr64 XHARD (far): final 0.119 vs baseline 0.183 , final much better. The real test (75-82) spans from near (75, 0 beyond) to moderately far (82, 7 beyond). Let me estimate which dominates. Public_test distribution: 75 cases in 75-80, 25 cases in 80-85 (actually 80-82). So most test cases (75%) are 75-80 (0-5 beyond ceiling 75) = "near" regime, and 25% are 80-82 (5-7 beyond) = "moderate" regime. Given most test cases are in the near regime (75-80, 0-5 beyond), the run7 result (near) is actually quite relevant! And there, baseline slightly edges final on mean (0.100 vs 0.108) because baseline's C_D is better at short range. Hmm. This makes me reconsider. The tradeoff is: - final: robust C_L (big win), slightly worse C_D at short range. - baseline: better C_D at short range, much worse C_L. Can I get the BEST of both? I want baseline-quality C_D (which is good at short range) AND final-quality C_L (robust). The issue with final's C_D at short range is that the physics augmentation with p=1.0 REPLACES the real velocity signal entirely with a global linear slope, discarding the baseline's more accurate learned C_D(velocity, geometry) relation. If I use p<1.0 (mix real and augmented), the model could learn BOTH the accurate near-range relation (from real data) AND the extrapolation behavior (from augmented). Earlier, p=0.5 with band aug hurt, and p=0.5 local+jitter hurt. But p=0.5 local WITHOUT jitter I didn't fully test cleanly... Actually run2 phys_local_p0.5+jit was bad (had jitter). Let me reconsider p variants without jitter. Alternatively, maybe the best approach is a SMALLER dhi or a partial p so C_D keeps its learned relation near the ceiling while still being taught the high-velocity …[truncated]
Important nuance: on a **near**-range pseudo-split (ceiling 69.5, test only 0–5.5 m/s beyond , which matches most of the real 75–80 test mass), the baseline's C_D is actually *better* (0.124 vs 0.177) because its learned C_D–velocity relation is still valid so close to the ceiling, while my p=1.0 augmentation discards that real signal. The final still wins big on C_L and on *far* extrapolation. This suggests a **partial augmentation** (mix real + augmented samples) could recover near-range C_D while keeping C_L robust. Let me test p∈{0.5,0.7} on the near split, also checking the farther sub-slice.
bash
cd /app && cat > /tmp/run8.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
ptr,ttr=load('train'); pva,tva=load('val')
pts=torch.cat([ptr,pva],0); tg=torch.cat([ttr,tva],0)
v=pts[:,0,2]; thr=69.5
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
far=v[tem]>=72.0
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
def log(s): open('/tmp/run8.log','a').write(s+'\n')
VAf=lambda p:{'kind':'local','dlo':-8,'dhi':20,'p':p}
F=lambda p:{'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'vel_aug':VAf(p),'swa':True,'loss':'huber','huber_delta':0.01}
base={'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4}
log('NEAR split ntest=%d nfar(>=72)=%d slope=%.3e'%(xte.shape[0],int(far.sum()),slope))
def run(name,cfg,seeds=(0,1)):
    A=[];Fa=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); A.append(metrics(pr,yte)); Fa.append(metrics(pr[far],yte[far]))
    a={k:float(np.mean([x[k] for x in A])) for k in A[0]}; fa={k:float(np.mean([x[k] for x in Fa])) for k in Fa[0]}
    log('%-12s | ALL mean=%.4f cd=%.4f cl=%.4f nmae=%.4f | FAR mean=%.4f cd=%.4f cl=%.4f'%(
        name,a['mean_nrmse'],a['cd_nrmse'],a['cl_nrmse'],a['cd_nmae'],fa['mean_nrmse'],fa['cd_nrmse'],fa['cl_nrmse']))
run('baseline',base); run('p1.0',F(1.0)); run('p0.7',F(0.7)); run('p0.5',F(0.5))
log('DONE')
EOF
rm -f /tmp/run8.log
nohup python3 /tmp/run8.py > /tmp/run8.stdout 2>&1 &
echo "started pid $!"
output
started pid 1640
This is 4 configs × 2 seeds, mix of 150ep (3 configs) and 100ep (baseline). ~ (3×2×150 + 2×100)×0.73 ≈ (900+200)×0.73/... wait let me recompute: per epoch ~0.73s for 629 samples. 150 ep ≈ 110s; 100 ep ≈ 73s. Total = baseline 2×73 + p1.0 2×110 + p0.7 2×110 + p0.5 2×110 = 146 + 660 = 806s ≈ 13.5 min. Let me wait. While waiting, let me think about the decision framework. After run8, I'll choose p that minimizes ALL-mean (near, most relevant) while keeping FAR robust and C_L low. If p=0.7 or p=0.5 gives C_D near baseline AND C_L near final, that's the winner and I'll retrain the final deliverable with that p. Let me wait ~290s then check partial. Actually, let me reconsider whether my current saved model (p=1.0) is a safe choice regardless. It's robust (low variance), physically sensible, wins clearly on C_L and on far extrapolation, and is only slightly behind baseline on near-range C_D. Even if run8 shows partial-p is better, the p=1.0 model is a defensible, solid deliverable. But if partial-p clearly dominates, I'll update. Let me wait for data. Let me wait.
Partial-augmentation sweep is running. Let me wait for results , if a partial `p` recovers near-range C_D while keeping C_L robust, I'll update the deliverable; otherwise the current p=1.0 model stands.
bash
sleep 295 && cat /tmp/run8.log 2>/dev/null
output
NEAR split ntest=81 nfar(>=72)=50 slope=-6.515e-05
baseline     | ALL mean=0.1018 cd=0.1273 cl=0.0763 nmae=0.0283 | FAR mean=0.0877 cd=0.1050 cl=0.0704
p1.0         | ALL mean=0.1060 cd=0.1743 cl=0.0378 nmae=0.0589 | FAR mean=0.1083 cd=0.1822 cl=0.0343
Hmm interesting. On this NEAR split: - baseline: ALL mean 0.102 (cd 0.127, cl 0.076); FAR mean 0.088 (cd 0.105, cl 0.070) - p1.0: ALL mean 0.106 (cd 0.174, cl 0.038); FAR mean 0.108 (cd 0.182, cl 0.034) Wait, on the FAR sub-slice (vel>=72, which is 2.5-5.5 beyond ceiling 69.5), baseline C_D is STILL better (0.105 vs 0.182) and even baseline C_L (0.070) is better than... no, p1.0 cl 0.034 < baseline 0.070. But baseline FAR mean (0.088) < p1.0 FAR mean (0.108) because baseline C_D is much better here. This is surprising , even at vel 72-75 (5.5 beyond ceiling 69.5), baseline C_D (0.105) beats p1.0 (0.182). This contradicts the thr64 result where at vel 70-75 (6-11 beyond ceiling 64), final C_D (0.189) beat baseline (0.226). The difference: ceiling matters. With ceiling 69.5 (more training data up to higher velocity, n=629), baseline learns a better C_D-velocity relation that extrapolates well to 75. With ceiling 64 (less data, n=468), baseline's relation is poorer and breaks down by 70-75. For the REAL model: ceiling 75, n=710 (even more data, higher ceiling). So baseline's C_D-velocity relation would be even BETTER and extrapolate well to 75-82? This suggests that with the full training data (ceiling 75), the baseline's learned C_D relation might actually extrapolate C_D quite well to 75-82, and the physics augmentation's crude global slope might HURT C_D. But baseline's C_L is consistently bad (overfits velocity): 0.076 near, and worse at farther ceilings. So the real tradeoff for the final model (ceiling 75): - C_D: baseline likely BETTER (its learned relation extrapolates well given lots of data up to 75). Physics aug hurts C_D. - C_L: physics aug MUCH better (robust), baseline overfits. Hmm. So maybe the ideal is: keep baseline's C_D behavior but fix C_L. This is the crux. How to fix C_L without disturbing C_D? The C_L overfitting to velocity: baseline C_L at near 0.076. Why does baseline C_L depend on velocity at all (it's physically ~independent)? Because the network, having velocity as input, uses it spuriously for C_L, and extrapolation amplifies the error. What if I augment velocity for C_L invariance but DON'T slope-adjust... no, that hurts C_D (invariant tells C_D it's velocity-independent too). The fundamental problem: shared network, can't separately tell it "use velocity for C_D, ignore for C_L." BUT , partial augmentation p<1 might let the network learn C_D from real data (accurate) while the augmented fraction teaches C_L invariance. The slope-adjustment in augmented fraction keeps C_D consistent (so augmented C_D samples don't conflict with real ones). Let me see p0.7 and p0.5 results , that's the key test. If p0.5 gives C_D close to baseline AND C_L close to p1.0, that's the winner. Let me wait for p0.7 and p0.5. Actually, let me reconsider. In the augmented fraction with slope adjustment, the C_D target at perturbed velocity is cd + slope*(newv-oldv). This is consistent with the real C_D-velocity relationship IF the true relationship has slope ≈ the estimated global slope. But the true relationship is geometry-dependent (the baseline learns a better, geometry-dependent relation). So even the slope-adjusted augmented C_D samples are slightly "wrong" (they impose global slope), which conflicts with the accurate real samples and degrades C_D. With p=0.5, half the samples impose the crude global slope → still degrades C_D somewhat, but less than p=1.0. The cleanest fix for C_L without touching C_D: what if I only apply velocity augmentation and adjust BOTH targets by their respective slopes, where C_L slope ≈ 0 (measured) and C_D slope = estimated? That's exactly what physics aug does (C_L slope 0). The issue is the C_D global slope being crude. Alternative: use a BETTER C_D adjustment in augmentation , a geometry-dependent slope. But that requires modeling slope per geometry, which is complex and what the network itself does better. Hmm. Let me think about this differently. What if the real si …[truncated]
Key realization: with **more training data up to a higher ceiling** (the real model has ceiling 75, n=710), the baseline's learned C_D–velocity relation extrapolates *well*, so the crude global-slope augmentation mainly *hurts* C_D , while baseline's C_L remains bad everywhere. The ideal is **baseline-quality C_D + robust C_L**. Let me see the partial-p results first.
bash
sleep 260 && cat /tmp/run8.log 2>/dev/null
output
NEAR split ntest=81 nfar(>=72)=50 slope=-6.515e-05
baseline     | ALL mean=0.1018 cd=0.1273 cl=0.0763 nmae=0.0283 | FAR mean=0.0877 cd=0.1050 cl=0.0704
p1.0         | ALL mean=0.1060 cd=0.1743 cl=0.0378 nmae=0.0589 | FAR mean=0.1083 cd=0.1822 cl=0.0343
p0.7         | ALL mean=0.0991 cd=0.1579 cl=0.0402 nmae=0.0526 | FAR mean=0.1016 cd=0.1665 cl=0.0367
p0.7: ALL mean 0.099 (cd 0.158, cl 0.040); FAR mean 0.102 (cd 0.167, cl 0.037). So p0.7 improves over p1.0 (ALL mean 0.099 vs 0.106), with C_D better (0.158 vs 0.174) and C_L similar (0.040). And p0.7 ALL mean (0.099) is now slightly BETTER than baseline (0.102)! Because C_L is much better (0.040 vs 0.076) while C_D is only moderately worse (0.158 vs 0.127). So partial augmentation helps. Let me see p0.5. The trend: lower p → better C_D (closer to baseline), but need to keep C_L robust. Let me see p0.5. This confirms my hypothesis: mixing real + augmented recovers C_D. The decouple scheme (C_D from real only, C_L from augmented) would be the logical extreme/refinement. Let me see p0.5 then decide.
`p0.7` now **beats baseline** on overall mean (0.099 vs 0.102): C_L stays robust (0.040 vs 0.076) while C_D recovers most of the gap (0.158 vs 0.127). Partial augmentation works. Let me see p0.5 and then implement the cleaner **decouple** scheme (learn C_D from real velocities, C_L from augmented ones).
bash
sleep 60 && cat /tmp/run8.log 2>/dev/null | tail -2
output
p0.5         | ALL mean=0.0906 cd=0.1405 cl=0.0407 nmae=0.0455 | FAR mean=0.0936 cd=0.1493 cl=0.0379
DONE
p0.5: ALL mean 0.091 (cd 0.140, cl 0.041); FAR mean 0.094 (cd 0.149, cl 0.038). Even better! p0.5 gives: - ALL mean 0.091 (vs baseline 0.102, p0.7 0.099, p1.0 0.106) - C_D 0.140 (closer to baseline 0.127, much better than p1.0 0.174) - C_L 0.041 (robust, much better than baseline 0.076) - FAR mean 0.094 (vs baseline 0.088) , baseline slightly better on FAR mean but only because baseline C_D 0.105 vs p0.5 0.149; p0.5 C_L 0.038 vs baseline 0.070. So p0.5 is the best overall on the NEAR split (ALL mean 0.091), beating baseline (0.102). The trend suggests even lower p might give better C_D but risk C_L. Let me check the decouple idea and maybe p0.3. Summary of NEAR split ALL mean: - baseline: 0.102 (cd 0.127, cl 0.076) - p1.0: 0.106 (cd 0.174, cl 0.038) - p0.7: 0.099 (cd 0.158, cl 0.040) - p0.5: 0.091 (cd 0.140, cl 0.041) Lower p → better. Let me test p0.3 and p0.2, and the decouple scheme (w_cd_aug=0, which is like "C_L augmented, C_D real only"). The decouple with w_cd_aug=0 should give C_D ≈ baseline (0.127) and C_L robust (~0.04), which would be ALL mean ≈ (0.127+0.04)/2 ≈ 0.084. Potentially the best! Let me implement the decouple scheme. In the augmentation: with prob p, perturb velocity for the C_L-invariance signal, but for C_D, either mask (w=0) or slope-adjust with weight w. Let me implement it cleanly in exp.py. I'll add a new config key 'decouple': {'p':.., 'w_cd_aug':..} using local dlo/dhi. For a decouple batch: - Start with real xb, yb. - Choose mask_aug = rand < p per sample. - newv = clamp(oldv + U(dlo,dhi)) where augmented, else oldv. - xb[:,:,2] = newv. - C_L target: original yb[:,1] (invariant) for ALL samples (augmented or not) , since C_L is velocity-invariant, using original C_L for perturbed velocity is correct. - C_D target: for augmented samples, cd + slope*(newv-oldv); for non-augmented, cd. - Loss weights: C_L weight = 1 for all. C_D weight: for augmented samples = w_cd_aug; for non-augmented = 1. Wait, but if I perturb velocity for augmented samples and set C_D weight=0 for them, then those samples only supervise C_L. But the non-augmented samples (fraction 1-p) supervise C_D at REAL velocities. With p=0.5, half the samples supervise C_D (at real velocities) , that's like training C_D on 50% data each epoch but over many epochs sees all. Fine. But actually, there's a cleaner formulation: ALWAYS keep a C_D supervision at real velocity AND add C_L supervision at augmented velocity. I.e., for each sample, compute: - C_L loss at augmented velocity (invariant target). - C_D loss at real velocity. But that requires two forward passes (one at real v for C_D, one at aug v for C_L) , 2x cost. Alternatively the per-sample mask approach (some samples real for C_D, some augmented for C_L) in one pass is cheaper and what p<1 already approximates. Actually the p0.5 result already does a version: with p=0.5, half samples keep real velocity (supervising both C_D and C_L correctly) and half get perturbed velocity with slope-adjusted C_D and invariant C_L. The "w_cd_aug" in current code is effectively 1.0 (augmented samples supervise C_D with slope-adjusted target). The decouple refinement (w_cd_aug=0) would make augmented samples NOT supervise C_D at all, so C_D is learned purely from real-velocity samples → should match baseline C_D more closely. Let me test w_cd_aug=0 vs the current p0.5 (w=1). Let me implement and test: decouple with p ∈ {0.5, 0.7} and w_cd_aug ∈ {0.0, 0.3}, plus p0.3 (w=1) for comparison. On the NEAR split + FAR sub-slice, 2 seeds. Actually, I want to also ensure FAR (extrapolation) C_D doesn't degrade with w_cd_aug=0 (no extrapolation hint). With w=0, C_D extrapolation = baseline-like (relies on smooth extension). That was decent in NEAR-FAR (baseline FAR cd 0.105). So w=0 might give C_D ~ baseline everywhere + robust C_L → best. But for the REAL test (further out, 82), a little extrapolation hint (w=0.3) might help C_D. Let me test both. Let me implement the decouple in exp.py trai …[truncated]
`p0.5` is the best yet (overall mean **0.091** vs baseline 0.102): C_D recovers to 0.140 while C_L stays robust at 0.041. Lower p → better. The logical refinement is to **decouple** supervision: learn C_D only from real-velocity samples (baseline-quality) while using augmented high-velocity samples solely to pin C_L flat. Let me implement per-sample loss weighting to test this.
str_replace_based_edit_tool
command: str_replace
path: /tmp/exp.py
old_str:             if vel_aug is not None:
                B=xb.shape[0]
                oldv=xb[:,0,2].clone()
                if isinstance(vel_aug,dict):
new_str:             wcd_s=None  # per-sample C_D weight (for decouple mode)
            if vel_aug is not None and vel_aug.get('decouple') if isinstance(vel_aug,dict) else False:
                B=xb.shape[0]; oldv=xb[:,0,2].clone()
                newv=(oldv+torch.empty(B).uniform_(vel_aug['dlo'],vel_aug['dhi'])).clamp(28.0,98.0)
                aug=(torch.rand(B)<vel_aug.get('p',0.5))
                newv=torch.where(aug,newv,oldv)
                xb[:,:,2]=newv.view(-1,1)
                # C_L target stays original (velocity-invariant); C_D slope-adjusted
                yb[:,0]=yb[:,0]+slope*(newv-oldv)
                w0=vel_aug.get('w_cd_aug',0.0)
                wcd_s=torch.where(aug,torch.full((B,),w0),torch.ones(B))
            elif vel_aug is not None:
                B=xb.shape[0]
                oldv=xb[:,0,2].clone()
                if isinstance(vel_aug,dict):
output
The file /tmp/exp.py has been edited successfully.
str_replace_based_edit_tool
command: str_replace
path: /tmp/exp.py
old_str:             loss=(wcd*per[:,0]+wcl*per[:,1]).mean()
new_str:             if wcd_s is not None:
                loss=(wcd*wcd_s*per[:,0]+wcl*per[:,1]).mean()
            else:
                loss=(wcd*per[:,0]+wcl*per[:,1]).mean()
output
The file /tmp/exp.py has been edited successfully.
Wait, there's a Python operator precedence issue in my condition: `if vel_aug is not None and vel_aug.get('decouple') if isinstance(vel_aug,dict) else False:` This is a conditional expression mixed with `and` , ambiguous/wrong. Let me fix it to a clean helper. Let me rewrite that line.
Let me fix a messy conditional I wrote (operator precedence is error-prone there).
str_replace_based_edit_tool
command: str_replace
path: /tmp/exp.py
old_str:             wcd_s=None  # per-sample C_D weight (for decouple mode)
            if vel_aug is not None and vel_aug.get('decouple') if isinstance(vel_aug,dict) else False:
new_str:             wcd_s=None  # per-sample C_D weight (for decouple mode)
            _decouple=isinstance(vel_aug,dict) and vel_aug.get('decouple',False)
            if _decouple:
output
The file /tmp/exp.py has been edited successfully.
bash
cd /app && python3 -c "
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch; torch.set_num_threads(2)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
p,t=load('train'); fm,fs=standardize_stats(p[:100]); tm=t[:100].mean(0); ts=t[:100].std(0).clamp_min(1e-8)
cfg={'epochs':2,'bs':64,'cd_slope':-6e-5,'vel_aug':{'decouple':True,'dlo':-8,'dhi':20,'p':0.5,'w_cd_aug':0.0},'loss':'huber','huber_delta':0.01}
m=train_model(p[:100],t[:100],cfg,fm,fs,tm,ts,seed=0)
print('decouple smoke ok', predict(m,p[:3],fm,fs,tm,ts).shape)
"
output
decouple smoke ok torch.Size([3, 2])
The decouple scheme works. Now let me test it on the NEAR split against the best p0.5 and baseline. Configs: - decouple p0.5 w0.0 (C_D from real only) - decouple p0.5 w0.3 (C_D mostly real + gentle extrapolation hint) - decouple p0.7 w0.0 - p0.3 (w=1, regular) for comparison Evaluate on NEAR split ALL and FAR. 2 seeds. Let me also keep the best so far (p0.5 regular, ALL 0.091) as reference in the log (I have it). Let me run run9.
The decouple scheme works. Let me test it against the best partial-p configs on the near split (with the far sub-slice to ensure extrapolation holds).
bash
cd /app && cat > /tmp/run9.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
ptr,ttr=load('train'); pva,tva=load('val')
pts=torch.cat([ptr,pva],0); tg=torch.cat([ttr,tva],0)
v=pts[:,0,2]; thr=69.5
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
far=v[tem]>=72.0
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
def log(s): open('/tmp/run9.log','a').write(s+'\n')
com={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'swa':True,'loss':'huber','huber_delta':0.01}
def D(p,w): return {**com,'vel_aug':{'decouple':True,'dlo':-8,'dhi':20,'p':p,'w_cd_aug':w}}
def P(p): return {**com,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':p}}
log('NEAR split slope=%.3e'%slope)
def run(name,cfg,seeds=(0,1,2)):
    A=[];Fa=[]
    for sd in seeds:
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); A.append(metrics(pr,yte)); Fa.append(metrics(pr[far],yte[far]))
    a={k:float(np.mean([x[k] for x in A])) for k in A[0]}; fa={k:float(np.mean([x[k] for x in Fa])) for k in Fa[0]}
    log('%-16s | ALL mean=%.4f cd=%.4f cl=%.4f nmae=%.4f | FAR mean=%.4f cd=%.4f cl=%.4f'%(
        name,a['mean_nrmse'],a['cd_nrmse'],a['cl_nrmse'],a['cd_nmae'],fa['mean_nrmse'],fa['cd_nrmse'],fa['cl_nrmse']))
run('decouple_p.5_w0',D(0.5,0.0))
run('decouple_p.5_w.3',D(0.5,0.3))
run('decouple_p.7_w0',D(0.7,0.0))
run('local_p0.3',P(0.3))
log('DONE')
EOF
rm -f /tmp/run9.log
nohup python3 /tmp/run9.py > /tmp/run9.stdout 2>&1 &
echo "started pid $!"
output
started pid 1793
This is 4 configs × 3 seeds × 150 ep ≈ 12 × 110s ≈ 22 min. That's long. Let me reduce by checking partial results as they come. Actually I set 3 seeds. Let me just poll; I can make a decision from partial results if needed. Let me wait ~290s for the first 1-2 configs. Actually, 3 seeds × 150 epochs each is ~330s per config. So first config ready ~330s. Let me wait 290s and check (maybe first config almost done). While waiting, let me reconsider: the NEAR split (ceiling 69.5) has FAR sub-slice at vel>=72 (2.5-5.5 beyond). The real test is 0-7 beyond ceiling 75. So the NEAR ALL (0-5.5 beyond) + a bit of FAR is the best analog. I'll primarily use NEAR ALL mean for selection, with FAR as a tiebreaker for extrapolation robustness. Current leaderboard (NEAR ALL mean, from run8 + run7): - p1.0: 0.106 - baseline: 0.102 - p0.7: 0.099 - p0.5: 0.091 - (decouple TBD) If decouple_p.5_w0 gives ~0.084 that's best. Let me see. Let me wait.
The decouple sweep is running (3 seeds each). Let me poll for the first results.
bash
sleep 295 && cat /tmp/run9.log 2>/dev/null
output
NEAR split slope=-6.515e-05
decouple_p.5_w0  | ALL mean=0.0735 cd=0.1014 cl=0.0456 nmae=0.0199 | FAR mean=0.0589 cd=0.0735 cl=0.0442
decouple_p.5_w0 (C_D from real velocities only, C_L pinned flat via augmentation): - ALL mean 0.0735 (cd 0.101, cl 0.046, nmae 0.020) - FAR mean 0.0589 (cd 0.074, cl 0.044) This is a BIG improvement! ALL mean 0.0735 vs best-so-far 0.091 (p0.5) and baseline 0.102. - C_D 0.101 , now BETTER than baseline (0.127)! Because C_D learned from real velocities only (no crude slope contamination), and the decoupling lets C_L augmentation not interfere. Actually C_D even beats baseline , interesting, probably because removing the C_L velocity-overfitting frees the shared representation, and MAE+SWA help. - C_L 0.046 , robust (vs baseline 0.076). - nmae 0.020 , excellent (vs baseline 0.028). - FAR C_D 0.074 , excellent extrapolation (baseline FAR cd was 0.105). So decouple_p.5_w0 dominates baseline on ALL metrics AND the p1.0/p0.5 configs. This is the winner so far. Let me see the other decouple variants (w0.3, p0.7, and local p0.3). This makes sense: the clean decoupling achieves exactly what I wanted , C_D learned accurately from real data (even better than baseline due to MAE+SWA and not fighting C_L's velocity misuse), and C_L made velocity-invariant via augmentation. Let me wait for the rest to confirm w0 is best (vs w0.3, which adds extrapolation hint). The FAR C_D 0.074 with w0 is already excellent, so the extrapolation hint (w0.3) may not be needed. But for the REAL test going further out (to 82, 7 beyond), a small hint might help C_D. Let me see w0.3. Let me wait.
**Big improvement.** `decouple_p.5_w0` (C_D learned only from real velocities, C_L pinned flat via augmentation) gives overall mean **0.0735** , beating baseline (0.102) on *every* metric: C_D 0.101 (vs 0.127), C_L 0.046 (vs 0.076), and even FAR C_D 0.074 (vs 0.105). The clean decoupling achieves exactly the goal. Let me confirm against the other variants.
bash
sleep 295 && cat /tmp/run9.log 2>/dev/null
output
NEAR split slope=-6.515e-05
decouple_p.5_w0  | ALL mean=0.0735 cd=0.1014 cl=0.0456 nmae=0.0199 | FAR mean=0.0589 cd=0.0735 cl=0.0442
decouple_p.5_w.3 | ALL mean=0.0901 cd=0.1371 cl=0.0432 nmae=0.0412 | FAR mean=0.0905 cd=0.1388 cl=0.0423
decouple_p.5_w.3: ALL mean 0.090 (cd 0.137, cl 0.043); FAR mean 0.091 (cd 0.139). So adding the C_D extrapolation hint (w0.3) HURTS C_D (0.137 vs 0.101 for w0). The slope-adjusted augmented C_D samples (crude global slope) contaminate C_D again. So w0 (no C_D augmentation, pure decouple) is clearly best. So the winner is decouple with w_cd_aug=0: C_D learned purely from real velocity data, C_L made velocity-invariant. Let me see p0.7_w0 and local_p0.3. The key insight validated: for C_D, the network's own learned relationship from real data (up to ceiling 75) extrapolates better than any crude global-slope hint I can inject. For C_L, augmentation to enforce velocity-invariance is crucial. Let me wait for the last two configs to confirm p0.5 is the right p (vs p0.7). Actually, with w=0, the p controls how many samples get velocity-augmented (for C_L invariance) vs kept real. Higher p → more C_L invariance signal but fewer real-velocity C_D samples per batch (though C_D weight is 1 on the (1-p) real samples). With p0.7_w0, more aggressive C_L augmentation, fewer real C_D samples. Let me see if p0.5 or p0.7 is better. Let me wait.
Adding a C_D extrapolation hint (w=0.3) *hurts* C_D (0.137 vs 0.101) , confirming the network's own learned C_D relation from real data beats any crude injected slope. **Pure decouple (w=0) is best.** Let me see the p=0.7 and local p=0.3 comparisons.
bash
sleep 290 && cat /tmp/run9.log 2>/dev/null
output
NEAR split slope=-6.515e-05
decouple_p.5_w0  | ALL mean=0.0735 cd=0.1014 cl=0.0456 nmae=0.0199 | FAR mean=0.0589 cd=0.0735 cl=0.0442
decouple_p.5_w.3 | ALL mean=0.0901 cd=0.1371 cl=0.0432 nmae=0.0412 | FAR mean=0.0905 cd=0.1388 cl=0.0423
decouple_p.7_w0  | ALL mean=0.0769 cd=0.1122 cl=0.0416 nmae=0.0230 | FAR mean=0.0621 cd=0.0833 cl=0.0410
decouple_p.7_w0: ALL mean 0.077 (cd 0.112, cl 0.042); FAR mean 0.062 (cd 0.083). So p0.7_w0 (ALL 0.077) is slightly worse than p0.5_w0 (ALL 0.074) on C_D (0.112 vs 0.101), slightly better on C_L (0.042 vs 0.046). Very close. p0.5_w0 edges it on the mean. Let me see local_p0.3 (last) then decide. Both p0.5_w0 and p0.7_w0 are excellent and beat everything else. p0.5_w0 is best on ALL mean (0.0735). Let me wait for local_p0.3 (the non-decouple p0.3 for reference), then finalize with decouple p0.5 w0. Actually, I should also consider p0.4 or p0.6 to fine-tune, but the gains are marginal and I risk overfitting my pseudo-split. p0.5 is a natural, robust choice. Let me also consider whether p should be a bit higher to ensure strong C_L invariance for the real test (which goes further out than my NEAR FAR slice). Since C_L invariance is what protects the farther extrapolation, and p0.7 had slightly better C_L (0.042 vs 0.046) and FAR was comparable, maybe p0.6 is a good balance. But differences are tiny. Let me go with p0.5, w_cd_aug=0 as the primary. But let me reconsider robustness for the REAL test which extends to 82 (7 beyond ceiling 75) , farther than my NEAR FAR (5.5 beyond). For C_L at the farthest points, more augmentation (higher p) gives more invariance robustness. p0.5 already augments 50% of samples across a wide velocity range (up to 95), so C_L invariance is well-taught across the whole range including 82-95. So p0.5 should be robust for C_L even at 82. Good. Let me confirm the decision and also double check the FAR (extrapolation) C_D for p0.5_w0 (0.074) is robust , yes, excellent. Let me wait for local_p0.3 then build the final model with decouple p0.5 w0. Actually, let me reconsider one more time if I should validate decouple p0.5 w0 on the FAR-er pseudo split (ceiling 64, test 70-75) to make sure it extrapolates C_D well even when the ceiling is lower / extrapolation longer. Because the real test (82) is 7 beyond ceiling, and my NEAR split only tested up to 5.5 beyond. The thr64 split tests 6-11 beyond. Let me verify decouple p0.5 w0 on thr64 to ensure C_D extrapolation holds when pushed further (since w0 gives NO extrapolation hint, relying on the net's smooth extension , need to confirm it doesn't degrade badly far out). Let me do a final validation run: decouple p0.5 w0 vs baseline vs p1.0(old final) on the thr64 split (FAR extrapolation), to confirm decouple still wins or at least holds when extrapolation is longer. This guards against the risk that w0 (no hint) extrapolates C_D poorly far out. Let me wait for run9 to finish first (local_p0.3), then run this validation. Let me wait.
`decouple_p.5_w0` remains the best (ALL mean 0.0735); p0.7 is close. Since the real test extends further out (to ~82, 7 m/s beyond the ceiling) than this near split tested, I must verify the pure-decouple C_D still extrapolates well over a *longer* gap (w=0 injects no extrapolation hint). Let me run a final guard test on the longer-extrapolation thr=64 split.
bash
sleep 60 && cat /tmp/run9.log 2>/dev/null | tail -2
cd /app && cat > /tmp/run10.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
pts,tg=load('train')  # train-only -> lower ceiling -> longer extrapolation
v=pts[:,0,2]; thr=64.0
trm=v<thr; tem=v>=thr
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
xh=v[tem]>=70  # 6-11 beyond ceiling
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
def log(s): open('/tmp/run10.log','a').write(s+'\n')
com={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'swa':True,'loss':'huber','huber_delta':0.01}
cfgs={
 'decouple_p.5_w0':{**com,'vel_aug':{'decouple':True,'dlo':-8,'dhi':20,'p':0.5,'w_cd_aug':0.0}},
 'decouple_p.7_w0':{**com,'vel_aug':{'decouple':True,'dlo':-8,'dhi':20,'p':0.7,'w_cd_aug':0.0}},
 'phys_p1.0(old)':{**com,'vel_aug':{'kind':'local','dlo':-8,'dhi':20,'p':1.0}},
 'baseline':{'epochs':100,'bs':64,'lr':1e-3,'wd':1e-4},
}
log('thr64 FAR XHARD(vel>=70,n=%d) slope=%.3e'%(int(xh.sum()),slope))
for name,cfg in cfgs.items():
    R=[]
    for sd in (0,1,2):
        m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
        pr=predict(m,xte,fm,fs,tm,ts); R.append(metrics(pr[xh],yte[xh]))
    a={k:float(np.mean([x[k] for x in R])) for k in R[0]}
    log('%-16s | mean=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(name,a['mean_nrmse'],a['cd_nrmse'],a['cl_nrmse'],a['cd_nmae']))
log('DONE')
EOF
rm -f /tmp/run10.log
nohup python3 /tmp/run10.py > /tmp/run10.stdout 2>&1 &
echo "started guard test pid $!"
output
decouple_p.5_w.3 | ALL mean=0.0901 cd=0.1371 cl=0.0432 nmae=0.0412 | FAR mean=0.0905 cd=0.1388 cl=0.0423
decouple_p.7_w0  | ALL mean=0.0769 cd=0.1122 cl=0.0416 nmae=0.0230 | FAR mean=0.0621 cd=0.0833 cl=0.0410
started guard test pid 1873
run9 final (local_p0.3) result wasn't shown in the tail (only last 2 lines). Let me check the full run9 log later. Actually the tail -2 showed decouple_p.5_w.3 and decouple_p.7_w0. The local_p0.3 might still be running or done. Let me not worry , decouple p0.5 w0 is the winner from run9. Now run10 (guard test, thr64 longer extrapolation, 3 seeds × 4 configs). This tests whether decouple w0 holds C_D extrapolation over a longer gap (6-11 beyond). ~4 configs × 3 seeds, 3×150ep for 3 configs + 3×100 baseline ≈ (9×110 + 3×73)×... on 468 samples ~0.49s/ep → 150ep≈74s, 100ep≈49s. Total ≈ 9×74 + 3×49 = 666+147 = 813s ≈ 13.5 min. Let me wait. Meanwhile let me check the full run9 log.
Let me check the complete run-9 log while the guard test runs.
bash
cat /tmp/run9.log 2>/dev/null
output
NEAR split slope=-6.515e-05
decouple_p.5_w0  | ALL mean=0.0735 cd=0.1014 cl=0.0456 nmae=0.0199 | FAR mean=0.0589 cd=0.0735 cl=0.0442
decouple_p.5_w.3 | ALL mean=0.0901 cd=0.1371 cl=0.0432 nmae=0.0412 | FAR mean=0.0905 cd=0.1388 cl=0.0423
decouple_p.7_w0  | ALL mean=0.0769 cd=0.1122 cl=0.0416 nmae=0.0230 | FAR mean=0.0621 cd=0.0833 cl=0.0410
The local_p0.3 config didn't finish/log yet , maybe run9 process was still going when I started run10, and they share CPU. Actually run9's 4th config (local_p0.3) might still be running concurrently with run10, slowing both. Let me check processes. Actually, I started run10 while run9 might still be finishing local_p0.3. Both use 8 threads on 16 cores, so they can run somewhat concurrently but will be slower. That's fine. Let me check if run9 is done. The decouple p0.5 w0 is clearly the best. I don't strictly need local_p0.3. Let me just wait for run10 (the guard test) which is the important one. Let me check processes and wait.
bash
sleep 250 && echo "run9:"; tail -1 /tmp/run9.log; echo "run10:"; cat /tmp/run10.log 2>/dev/null
output
run9:
DONE
run10:
thr64 FAR XHARD(vel>=70,n=70) slope=-6.165e-05
decouple_p.5_w0  | mean=0.1131 cd=0.1698 cl=0.0565 nmae=0.0460
run9 is DONE (local_p0.3 finished but I didn't capture its line , not important). run10 guard test (thr64, longer extrapolation 6-11 beyond ceiling 64): - decouple_p.5_w0: mean 0.113 (cd 0.170, cl 0.057, nmae 0.046) Let me recall the thr64 XHARD numbers from before (run6): final(p1.0) mean 0.119 (cd 0.189, cl 0.048); baseline mean 0.183 (cd 0.226, cl 0.139). So decouple_p.5_w0 on thr64 XHARD: mean 0.113, cd 0.170 , BETTER than p1.0 (cd 0.189) and baseline (cd 0.226)! Even over the LONGER extrapolation (6-11 beyond), the decouple w0 C_D (0.170) extrapolates better than baseline and even better than the physics-hint p1.0. This is reassuring: even with NO explicit extrapolation hint (w0), the network's learned C_D relation (from real data up to ceiling) extrapolates well, AND the C_L is robust. So decouple_p.5_w0 is the clear winner across BOTH near (run9) and far (run10) extrapolation. Let me wait for the other run10 configs (p0.7_w0, p1.0, baseline) to complete the comparison and confirm. Let me wait.
The guard test confirms it: over the **longer** extrapolation (6–11 m/s beyond ceiling), `decouple_p.5_w0` gets C_D 0.170 , better than both the old physics-hint p1.0 (0.189) and baseline (0.226), even with *no* explicit extrapolation hint. The network's learned C_D relation extrapolates well on its own. Let me see the rest.
bash
sleep 280 && cat /tmp/run10.log 2>/dev/null
output
thr64 FAR XHARD(vel>=70,n=70) slope=-6.165e-05
decouple_p.5_w0  | mean=0.1131 cd=0.1698 cl=0.0565 nmae=0.0460
decouple_p.7_w0  | mean=0.1529 cd=0.2532 cl=0.0527 nmae=0.0725
Interesting: on the thr64 longer extrapolation: - decouple_p.5_w0: mean 0.113 (cd 0.170, cl 0.057) - decouple_p.7_w0: mean 0.153 (cd 0.253, cl 0.053) So p0.7_w0 has WORSE C_D (0.253) than p0.5_w0 (0.170) here. Because with p0.7, fewer real-velocity samples supervise C_D (only 30% of samples per batch keep real velocity), so C_D is learned from less real data → worse, especially extrapolation. p0.5 keeps 50% real → better C_D. So p0.5 is better than p0.7 for C_D, confirming p0.5_w0 as the sweet spot. This makes sense: with w0, the (1-p) fraction of real-velocity samples is the ONLY C_D supervision. So I want enough real samples → p not too high. p0.5 gives 50% real. Maybe even lower p (0.4, 0.3) gives more real C_D samples but less C_L invariance. p0.5 balances. Let me wait for p1.0 and baseline in run10 to complete the picture (p1.0 and baseline already known approximately from run6: p1.0 cd 0.189, baseline cd 0.226). Let me confirm. Actually I have enough. decouple_p.5_w0 is the clear, robust winner: - NEAR (run9): ALL mean 0.0735, cd 0.101, cl 0.046 - FAR/thr64 (run10): mean 0.113, cd 0.170, cl 0.057 Both beat baseline and all other configs. Decision: Final model = decouple augmentation, p=0.5, w_cd_aug=0, dlo=-8, dhi=20, MAE loss (smooth_l1 beta 0.01), SWA, 150 epochs, trained on train+val. Let me now update final_train.py to use the decouple scheme (currently it uses the p1.0 physics aug). Let me modify the train() function to implement decouple. Let me wait for run10 to finish first (to confirm p1.0/baseline), then update final_train.py and regenerate the checkpoint. Let me wait a bit for run10.
Clear: `p0.5` beats `p0.7` for C_D (0.170 vs 0.253) because with w=0 the *real-velocity* samples are the only C_D supervision, so I need enough of them (50%). **`decouple_p.5_w0` is the robust winner across both near and far extrapolation.** Let me confirm the last two references, then update the final trainer.
bash
sleep 230 && cat /tmp/run10.log 2>/dev/null
output
thr64 FAR XHARD(vel>=70,n=70) slope=-6.165e-05
decouple_p.5_w0  | mean=0.1131 cd=0.1698 cl=0.0565 nmae=0.0460
decouple_p.7_w0  | mean=0.1529 cd=0.2532 cl=0.0527 nmae=0.0725
phys_p1.0(old)   | mean=0.1232 cd=0.1955 cl=0.0509 nmae=0.0647
phys_p1.0(old): mean 0.123 (cd 0.196, cl 0.051). So on thr64 longer extrapolation: - decouple_p.5_w0: mean 0.113 (cd 0.170) ← best - phys_p1.0(old): mean 0.123 (cd 0.196) - decouple_p.7_w0: mean 0.153 (cd 0.253) decouple_p.5_w0 wins. Baseline (last) is running, expected ~0.183. Let me not wait for baseline (known to be worst). Let me finalize: update final_train.py to implement the decouple scheme (p=0.5, w_cd_aug=0) and regenerate the checkpoint. Let me update the train() function in final_train.py. The current augmentation block: ``` B = xb.shape[0]; oldv = xb[:, 0, 2].clone() newv = (oldv + torch.empty(B).uniform_(dlo, dhi)).clamp(clo, chi) mask = (torch.rand(B) < p).float() newv = mask * newv + (1 - mask) * oldv xb[:, :, 2] = newv.view(-1, 1) yb[:, 0] = yb[:, 0] + slope * (newv - oldv) xs = (xb - fmv) / fsv; ys = (yb - tmv) / tsv opt.zero_grad(set_to_none=True) loss = F.smooth_l1_loss(model(xs), ys, beta=0.01) loss.backward(); opt.step() ``` I need to change to decouple: - aug = rand < p (bool per sample) - newv = clamp(oldv + U(dlo,dhi)) where aug else oldv - C_L target stays original; C_D target = cd + slope*(newv-oldv) [but since w_cd_aug=0, the C_D loss on augmented samples is masked, so the C_D target value for augmented samples doesn't matter , but I'll still set it consistently] - per-sample C_D weight: 1 for real (not aug), w_cd_aug (=0) for aug. - loss = mean over batch and targets with weights: for C_D use smooth_l1 per-sample * wcd_s; for C_L use smooth_l1 per-sample * 1. Since smooth_l1_loss with reduction='none' gives per-element loss, I can compute per-sample per-target and apply weights. Let me rewrite. I'll compute: ``` pred = model(xs) # [B,2] standardized per = F.smooth_l1_loss(pred, ys, beta=0.01, reduction='none') # [B,2] loss = (wcd_s * per[:,0] + per[:,1]).mean() ``` where wcd_s is per-sample weight (1 for real, 0 for aug). Note: using .mean() over the sum , the normalization. With wcd_s having zeros for aug samples, the C_D term only counts real samples but divides by B. That's fine (consistent scaling). Alternatively divide by counts, but .mean() is fine and matches what exp.py did (it used .mean() on wcd*wcd_s*per[:,0]+wcl*per[:,1]). Let me match exp.py exactly: loss=(wcd*wcd_s*per[:,0]+wcl*per[:,1]).mean() with wcd=wcl=1. Good. Let me also add parameters p and w_cd_aug to train() signature with defaults p=0.5, w_cd_aug=0.0. Also, the SWA BN refresh loop perturbs velocity , I should keep that so BN stats cover the augmented (high-velocity) range. But in decouple, real samples keep velocity and aug samples perturb. For BN refresh, I want BN stats to reflect the full velocity range seen at test (75-82) and beyond. Let me perturb velocity in the refresh with the same aug distribution (p=0.5 perturbation). Actually, to ensure BN running stats cover high velocities well, let me perturb MORE aggressively in refresh (e.g., always perturb upward) OR just use the same scheme. Let me use the same per-sample aug (p) in refresh so BN sees a representative mix. Actually, at test ALL samples have high velocity (75-82). So BN running stats should be representative of high velocities. If during refresh only 50% are perturbed up, BN stats are a mix of low and high. That might slightly mismatch test (all high). Hmm, this is a subtle but important point for BN. At test, every sample has velocity 75-82. The BN running stats (mean/var per channel) computed during training/refresh should ideally match the test input distribution for the conv features. If training sees a mix of velocities (31-95), BN stats reflect that mix. At test (all 75-82), the actual batch statistics differ, but BN uses RUNNING stats (fixed), so each test sample is normalized by the training-mix stats. This is the standard train/test BN behavior and the model weights are trained to work with running stats. Since the …[truncated]
Decision confirmed: **`decouple_p.5_w0`** is the robust winner across near *and* far extrapolation. Note that with w=0 the slope adjustment is multiplied by zero weight, so C_D is learned purely from real-velocity samples while augmented high-velocity samples supervise only the (velocity-invariant) C_L. Let me rewrite the final trainer to implement this cleanly.
str_replace_based_edit_tool
command: str_replace
path: /app/final_train.py
old_str: def train(points, targets, *, epochs=150, bs=64, lr=1e-3, wd=1e-4, seed=0,
          dlo=-8.0, dhi=20.0, p=1.0, clo=28.0, chi=98.0, swa=True, swa_frac=0.7,
          slope=None, verbose=True):
    torch.manual_seed(seed); np.random.seed(seed)
    fm, fs = _coord_stats(points)
    tm = targets.mean(0); ts = targets.std(0).clamp_min(1e-8)
    if slope is None:
        slope = estimate_cd_slope(points, targets[:, 0])
    model = build_model(CFG)
    opt = torch.optim.Adam(model.parameters(), lr=lr, weight_decay=wd)
    sched = torch.optim.lr_scheduler.CosineAnnealingLR(opt, T_max=epochs)
    n = points.shape[0]
    fmv = fm.view(1, 1, -1); fsv = fs.view(1, 1, -1); tmv = tm.view(1, -1); tsv = ts.view(1, -1)
    swa_start = int(epochs * swa_frac); swa_state = None; swa_n = 0
    for e in range(epochs):
        model.train(); perm = torch.randperm(n)
        for s in range(0, n, bs):
            idx = perm[s:s + bs]
            xb = points[idx].clone(); yb = targets[idx].clone()
            B = xb.shape[0]; oldv = xb[:, 0, 2].clone()
            newv = (oldv + torch.empty(B).uniform_(dlo, dhi)).clamp(clo, chi)
            mask = (torch.rand(B) < p).float()
            newv = mask * newv + (1 - mask) * oldv
            xb[:, :, 2] = newv.view(-1, 1)
            yb[:, 0] = yb[:, 0] + slope * (newv - oldv)
            xs = (xb - fmv) / fsv; ys = (yb - tmv) / tsv
            opt.zero_grad(set_to_none=True)
            # MAE-like (Huber with tiny beta) on standardized targets: robust to
            # C_D's right-skewed high-drag outliers, which improves extrapolation.
            loss = F.smooth_l1_loss(model(xs), ys, beta=0.01)
            loss.backward(); opt.step()
        sched.step()
        if swa and e >= swa_start:
            sd = {k: v.detach().clone() for k, v in model.state_dict().items()}
            if swa_state is None:
                swa_state = sd; swa_n = 1
            else:
                swa_n += 1
                for k in swa_state:
                    if swa_state[k].dtype.is_floating_point:
                        swa_state[k] += (sd[k] - swa_state[k]) / swa_n
    if swa and swa_state is not None:
        model.load_state_dict(swa_state)
        model.train()
        with torch.no_grad():  # refresh BN running stats for the averaged weights
            for _ in range(3):
                for s in range(0, n, bs):
                    xb = points[s:s + bs].clone()
                    xb[:, :, 2] = (xb[:, :, 2] + torch.empty(xb.shape[0], 1).uniform_(dlo, dhi)).clamp(clo, chi)
                    model((xb - fmv) / fsv)
    model.eval()
    return model, fm, fs, tm, ts, slope
new_str: def _augment(xb, yb, *, dlo, dhi, p, clo, chi, slope, w_cd_aug):
    """Decoupled velocity augmentation.

    A fraction ``p`` of samples get their inlet velocity perturbed (biased
    upward, out past the test range). For those samples C_L is kept fixed
    (it is velocity-invariant) and their C_D loss is down-weighted to
    ``w_cd_aug`` (0 by default). Net effect: C_D is learned only from real
    velocities (so the network's own accurate, geometry-dependent Reynolds
    trend is preserved and extends past the ceiling), while C_L is taught to
    ignore velocity across the whole range -> robust high-velocity C_L.
    Returns augmented xb, yb and a per-sample C_D loss weight.
    """
    B = xb.shape[0]; oldv = xb[:, 0, 2].clone()
    aug = torch.rand(B) < p
    newv = (oldv + torch.empty(B).uniform_(dlo, dhi)).clamp(clo, chi)
    newv = torch.where(aug, newv, oldv)
    xb[:, :, 2] = newv.view(-1, 1)
    yb[:, 0] = yb[:, 0] + slope * (newv - oldv)  # only matters if w_cd_aug>0
    wcd = torch.where(aug, torch.full((B,), float(w_cd_aug)), torch.ones(B))
    return xb, yb, wcd


def train(points, targets, *, epochs=150, bs=64, lr=1e-3, wd=1e-4, seed=0,
          dlo=-8.0, dhi=20.0, p=0.5, w_cd_aug=0.0, clo=28.0, chi=98.0,
          swa=True, swa_frac=0.7, slope=None, verbose=True):

…[truncated]
output
The file /app/final_train.py has been edited successfully.
Now let me also update the docstring at the top to reflect the decouple scheme (the current one describes the slope-adjustment approach). Let me update it for accuracy. Actually the top docstring describes physics augmentation with slope; the decouple is a refinement. Let me update it to be accurate. Let me update the module docstring.
Let me update the module docstring to accurately describe the final decouple method.
str_replace_based_edit_tool
command: str_replace
path: /app/final_train.py
old_str: Key idea (see notes): the scored cases live at higher inlet velocity / Reynolds
than training. Physically, C_L is essentially velocity-independent while C_D has
a mild, monotonic decreasing dependence on velocity (Reynolds drag reduction).
We therefore train with a physics-based velocity augmentation: each sample's
inlet velocity is randomly perturbed (biased upward, beyond the test range) and
C_D is shifted by an estimated linear Reynolds slope while C_L is held fixed.
This simultaneously (a) teaches C_L to ignore velocity -> robust extrapolation,
and (b) teaches C_D the correct velocity trend and extends it past the training
ceiling. The architecture and checkpoint contract are unchanged.
new_str: Key idea (see notes): the scored cases live at higher inlet velocity / Reynolds
than training. Empirically (controlling for geometry + AoA), C_L is essentially
velocity-independent, while C_D has only a mild, monotonic decreasing dependence
on velocity (Reynolds drag reduction) that the network already extrapolates well
from the real data. The failure mode of a plain fit is that C_L latches onto
velocity spuriously and then degrades badly once velocity leaves the training
range.

We fix this with a *decoupled* velocity augmentation. A fraction of samples per
batch have their inlet velocity perturbed far past the test range; for those
samples only the (velocity-invariant) C_L is supervised, while the C_D loss is
switched off. So C_D is learned purely from real-velocity samples -- preserving
the network's own accurate, geometry-dependent Reynolds trend and its smooth
extension past the ceiling -- and C_L is taught to ignore velocity everywhere,
which makes its high-velocity extrapolation robust. Combined with an MAE-like
loss (robust to C_D's high-drag outliers) and SWA, this beats a plain fit on
both coefficients in and beyond the training velocity range. The architecture
and checkpoint contract are unchanged.
output
The file /app/final_train.py has been edited successfully.
Now let me regenerate the final checkpoint with the validated decouple method and verify it end-to-end.
bash
cd /app && python3 -c "import ast; ast.parse(open('final_train.py').read()); print('final_train.py syntax OK')" && rm -f outputs/model.pt && NT=8 SEED=0 nohup python3 final_train.py > /tmp/final2.log 2>&1 &
echo "started final training pid $!"
output
started final training pid 1980
bash
sleep 180 && cat /tmp/final2.log 2>/dev/null; echo '---'; ls -la /app/outputs/model.pt 2>/dev/null
output
[final] training on 710 cases (train+val)
[final] slope=-5.907e-05 feat_mean=[0.38364875316619873, 0.007897475734353065, 53.19941711425781, 0.07678442448377609] targ_mean=[0.012753964401781559, 0.6618618965148926]
[final] wrote /app/outputs/model.pt
---
-rw-r--r-- 1 h2tagent h2tagent 346611 Jun 19 23:56 /app/outputs/model.pt
The final checkpoint is regenerated. Let me run the full grader-style verification plus the physical sanity checks.
bash
cd /app && python3 -c "
import json,torch,sys; sys.path.insert(0,'/app')
from candidate_model import build_model
cfg=json.load(open('task_config.json'))
ck=torch.load('outputs/model.pt',weights_only=True)
assert sorted(ck)== ['feat_mean','feat_std','state_dict','targ_mean','targ_std'], sorted(ck)
for k,n in [('feat_mean',4),('feat_std',4),('targ_mean',2),('targ_std',2)]:
    t=ck[k]; assert tuple(t.shape)==(n,), (k,t.shape); assert t.dtype==torch.float32
    assert torch.isfinite(t).all() and (ck['feat_std']>0).all() and (ck['targ_std']>0).all()
m=build_model(cfg); m.load_state_dict(ck['state_dict'],strict=True); m.eval()
fm=ck['feat_mean'].view(1,1,-1); fs=ck['feat_std'].view(1,1,-1); tm=ck['targ_mean'].view(1,-1); ts=ck['targ_std'].view(1,-1)
pts=torch.load('data/public_test/split.pt',weights_only=True)['points'].float()
with torch.no_grad(): pred=m((pts-fm)/fs)*ts+tm
cd,cl=pred[:,0],pred[:,1]
print('ALL CHECKS PASS: keys, shapes, dtypes, strict load, positive stds')
print('public_test C_D: min=%.5f max=%.5f mean=%.5f  | C_L: min=%.3f max=%.3f mean=%.3f'%(cd.min(),cd.max(),cd.mean(),cl.min(),cl.max(),cl.mean()))
print('no NaN:',torch.isfinite(pred).all().item(),' C_D>0:',(cd>0).all().item())
# physics sanity: C_D decreasing, C_L flat vs velocity
import numpy as np
mono=0; flat=[]
for i in range(pts.shape[0]):
    b0=pts[i:i+1].clone()
    cds=[]; cls=[]
    for v in [70,75,80,85]:
        b=b0.clone(); b[:,:,2]=float(v)
        with torch.no_grad(): o=m((b-fm)/fs)*ts+tm
        cds.append(o[0,0].item()); cls.append(o[0,1].item())
    if cds[0]>cds[1]>cds[2]>cds[3]: mono+=1
    flat.append(abs(cls[-1]-cls[0]))
print('C_D strictly decreasing with velocity in %d/%d cases'%(mono,pts.shape[0]))
print('median |C_L(85)-C_L(70)| = %.4f (C_L std ~0.58) -> near velocity-invariant'%np.median(flat))
"
output
ALL CHECKS PASS: keys, shapes, dtypes, strict load, positive stds
public_test C_D: min=0.00743 max=0.02525 mean=0.01182  | C_L: min=-0.569 max=1.740 mean=0.644
no NaN: True  C_D>0: True
C_D strictly decreasing with velocity in 21/100 cases
median |C_L(85)-C_L(70)| = 0.0101 (C_L std ~0.58) -> near velocity-invariant
The checkpoint passes all format checks. The predictions are sane: - C_D: [0.0074, 0.025], mean 0.0118 (below train mean 0.0128, consistent with higher velocity → lower drag). - C_L: [-0.57, 1.74], mean 0.644 (similar to train 0.66, velocity-invariant). - No NaN, C_D>0. - C_L is near velocity-invariant (median change 0.010 over velocity 70→85, tiny vs std 0.58). But C_D strictly decreasing in only 21/100 cases over [70,75,80,85]? That's concerning , I expected monotonic decrease. Let me investigate. Earlier (the p1.0 model) the sweep showed clear monotonic decrease. With decouple w0, C_D extrapolation relies on the network's own learned relation without the slope hint, so the velocity dependence in the extrapolation region (75-85) might be flatter or non-monotonic for some cases. Wait, the test region of interest is mostly 75-82. Let me check monotonicity in a finer, relevant range and the actual magnitude of change. The "strictly decreasing across 70,75,80,85" is a strict test; maybe C_D is decreasing but with tiny non-monotonic wiggles, or flattening at high velocity. Let me check the average C_D trend across velocity, and whether it's at least non-increasing on average. The important thing is that predictions in 75-82 are accurate, not strict monotonicity. Let me examine the C_D velocity trend more carefully: average over cases of C_D at each velocity, and a few example sweeps. Since w0 means no slope hint, the model learned C_D(velocity) purely from real data (31-75). In the extrapolation region (75-85), it extends however the network does. It might flatten (not continue decreasing). Let me check if that's a problem. Actually, recall the validation: decouple_p.5_w0 got excellent C_D on held-out high velocities (NEAR cd 0.101, thr64 XHARD cd 0.170) , better than the slope-hint version. So even if the extrapolation isn't strictly monotonic per-case, it's ACCURATE on real held-out high-velocity data. That's what matters. The strict monotonicity is a nice-to-have, not the objective. The validation on real held-out data is the ground truth, and decouple w0 won there. But let me double-check by looking at the average trend and a few examples, to make sure nothing pathological (like C_D increasing sharply) happens in 75-82. Let me inspect.
All format checks pass and predictions are physically sane (C_D mean below training mean; C_L near velocity-invariant). The "strictly decreasing in only 21/100" flag is worth inspecting , with the pure-decouple method C_D extrapolation relies on the network's own learned trend (no injected slope), so let me verify the behavior in the relevant 75–82 band isn't pathological.
bash
cd /app && python3 -c "
import json,torch,numpy as np,sys; sys.path.insert(0,'/app')
from candidate_model import build_model
cfg=json.load(open('task_config.json')); ck=torch.load('outputs/model.pt',weights_only=True)
m=build_model(cfg); m.load_state_dict(ck['state_dict']); m.eval()
fm=ck['feat_mean'].view(1,1,-1); fs=ck['feat_std'].view(1,1,-1); tm=ck['targ_mean'].view(1,-1); ts=ck['targ_std'].view(1,-1)
pts=torch.load('data/public_test/split.pt',weights_only=True)['points'].float()
vels=[50,60,70,75,78,82,88]
avg=[]
for v in vels:
    b=pts.clone(); b[:,:,2]=float(v)
    with torch.no_grad(): o=m((b-fm)/fs)*ts+tm
    avg.append(o[:,0].mean().item())
print('mean C_D vs velocity:')
for v,a in zip(vels,avg): print('  v=%2d  C_D=%.5f'%(v,a))
# fraction non-increasing from 70->82 (the real test band)
def cdv(v):
    b=pts.clone(); b[:,:,2]=float(v)
    with torch.no_grad(): return (m((b-fm)/fs)*ts+tm)[:,0]
c70,c75,c82=cdv(70),cdv(75),cdv(82)
print('within 70->82: non-increasing in %d/100; mean delta(82-70)=%.5f'%(int(((c82<=c70+1e-6)).sum()), (c82-c70).mean().item()))
print('per-case C_D(82) still within training C_D range [0.007,0.046]:', bool(((c82>0.004)&(c82<0.05)).all().item()))
"
output
mean C_D vs velocity:
  v=50  C_D=0.01296
  v=60  C_D=0.01251
  v=70  C_D=0.01205
  v=75  C_D=0.01187
  v=78  C_D=0.01181
  v=82  C_D=0.01178
  v=88  C_D=0.01189
within 70->82: non-increasing in 71/100; mean delta(82-70)=-0.00027
per-case C_D(82) still within training C_D range [0.007,0.046]: True
Now it's clear. On AVERAGE, C_D decreases with velocity as expected: - v=50: 0.01296, v=60: 0.01251, v=70: 0.01205, v=75: 0.01187, v=78: 0.01181, v=82: 0.01178, then v=88: 0.01189 (slight uptick far out at 88). So the mean trend is correctly decreasing through the test range (up to 82), flattening and very slightly rising only at 88 (beyond the test range). Within 70→82, 71/100 cases are non-increasing, and the mean delta is -0.00027 (decreasing). The per-case C_D(82) all stay within the training C_D range (no blow-up). The earlier "strictly decreasing in 21/100 across 70,75,80,85" was strict because the trend FLATTENS at high velocity (the network's learned relation saturates), so tiny wiggles break strict monotonicity, but the overall behavior is correct and bounded. The flattening at very high velocity is actually physically reasonable (drag reduction slows at high Re), and more importantly the model is ACCURATE on held-out high-velocity data (validated). This is fine. The model behaves well in the test range (75-82): C_D gently decreasing/flat, bounded, C_L invariant. So the decouple w0 model is good. But let me reconsider: the mean C_D decrease from 70→82 is only -0.00027, which is quite flat (the network's learned extrapolation saturates). The "true" slope from the regression suggested ~-5.9e-5/m/s × 12 m/s ≈ -0.0007. So the network's extrapolated decrease (-0.00027 over 12 m/s ≈ -2.3e-5/m/s) is gentler than the estimated physical slope. This means C_D at 82 might be slightly OVER-predicted (true C_D a bit lower). Hmm. This is the tradeoff I identified: decouple w0 relies on the network's own extrapolation, which flattens (conservative). The slope-hint version would push C_D lower at high velocity. But in my validation (thr64 XHARD, which is 6-11 beyond ceiling), decouple w0 got cd 0.170 vs p1.0 (slope hint) cd 0.196 , decouple was BETTER despite flatter extrapolation. So the flattening isn't hurting; in fact the slope-hint's more aggressive decrease was LESS accurate. The held-out data validates decouple w0. So I'll trust it. But wait , let me reconsider whether a SMALL slope hint might help at the far end (82) specifically. My validation showed w0.3 hurt (NEAR cd 0.137 vs w0 0.101). And w0 won on both near and far. So no hint is best per validation. Actually, let me reconsider the possibility that a tiny hint (w=0.1 or w=0.15) could help the far end without hurting near. But the validation trend (w0=0.101, w0.3=0.137) suggests monotonic degradation with w. So w0 is best. I'll stick with w0. I'm confident in the decouple w0 model. Now, let me do a final robustness consideration: seed. The final model uses seed 0. Let me verify seed stability for the decouple config by quickly checking the pseudo-split numbers were stable. In run9/run10 I used 3 seeds and reported means but not stds. Let me quickly confirm seed variance is low for decouple p0.5 w0 on the train+val NEAR split, and compare seed 0 specifically. Actually, given SWA and the strong consistent results, and limited budget, I'll trust it. But let me do one quick check: train decouple p0.5 w0 with seeds 0,1,2 on NEAR split and report individual mean_nrmse to confirm seed 0 isn't an outlier. Actually, I realize I should also consider: the final model is trained on ALL train+val (no holdout), so I can't directly measure its quality. But the config is validated. The concern is only seed variance. Let me do a quick seed-variance check on the NEAR pseudo-split (train on <69.5, which is what I can measure) for the decouple config, 3 seeds individually. This is ~3×110s = 5.5 min. Let me do it to be safe, in the background. Actually, let me reconsider the budget. I have ~64k tokens left. Let me be efficient. The seed check is worth it for confidence. Let me run it quickly (3 seeds, but maybe 120 epochs to save time) and also produce a final summary comparison table. Let me run a final confirmation: decouple p0.5 w0 individual seeds on NEAR split, and also …[truncated]
The behavior is correct: **mean C_D decreases monotonically through the entire test band** (0.0130 at v=50 → 0.0118 at v=82), stays bounded within the training range, and only flattens/ticks up slightly at v=88 (beyond the test range). The flattening is why strict per-case monotonicity was low, but the held-out validation already proved this pure-decouple C_D is *more* accurate than the aggressive slope-hint version. C_L is invariant. Let me do a final seed-stability check (the deliverable uses seed 0, trained on all data with no holdout) to confirm seed 0 isn't an outlier.
bash
cd /app && cat > /tmp/seedchk.py << 'EOF'
import sys; sys.path.insert(0,'/tmp'); sys.path.insert(0,'/app')
import torch,numpy as np
torch.set_num_threads(8)
from exp import load,standardize_stats,train_model,predict,metrics,estimate_cd_slope
ptr,ttr=load('train'); pva,tva=load('val')
pts=torch.cat([ptr,pva],0); tg=torch.cat([ttr,tva],0)
v=pts[:,0,2]; trm=v<69.5; tem=v>=69.5
xtr,ytr=pts[trm],tg[trm]; xte,yte=pts[tem],tg[tem]
fm,fs=standardize_stats(xtr); tm=ytr.mean(0); ts=ytr.std(0).clamp_min(1e-8)
slope=estimate_cd_slope(xtr,ytr)
cfg={'epochs':150,'bs':64,'lr':1e-3,'wd':1e-4,'cd_slope':slope,'swa':True,'loss':'huber','huber_delta':0.01,
     'vel_aug':{'decouple':True,'dlo':-8,'dhi':20,'p':0.5,'w_cd_aug':0.0}}
def log(s): open('/tmp/seedchk.log','a').write(s+'\n')
for sd in (0,1,2,3):
    m=train_model(xtr,ytr,cfg,fm,fs,tm,ts,seed=sd)
    r=metrics(predict(m,xte,fm,fs,tm,ts),yte)
    log('seed=%d mean_nrmse=%.4f cd=%.4f cl=%.4f nmae=%.4f'%(sd,r['mean_nrmse'],r['cd_nrmse'],r['cl_nrmse'],r['cd_nmae']))
log('DONE')
EOF
rm -f /tmp/seedchk.log
nohup python3 /tmp/seedchk.py > /tmp/seedchk.stdout 2>&1 &
echo "started seed check pid $!"
output
started seed check pid 4519
While the seed check runs (~4 seeds × 110s ≈ 7.5 min), let me write up notes documenting my approach, and clean up. Let me create a NOTES.md in /app/outputs or /app documenting the methodology and results. Actually, the task only requires the checkpoint at /app/outputs/model.pt. But documenting is good practice. Let me write a concise notes file. Let me also make sure I haven't left the outputs directory with anything stale. The model.pt is there (from the decouple training). Good. Let me write notes while waiting. Let me also reconsider: should I verify that the grading harness would use weights_only=True load and that my tensors are plain float32 (they are). Also, the state_dict includes BatchNorm running stats and num_batches_tracked. Those load fine with strict=True (verified). Good. Let me write the notes.
While the seed check runs, let me document the methodology and findings in a notes file.
str_replace_based_edit_tool
command: create
path: /app/outputs/NOTES.md
file_text: # Airfoil force-coefficient surrogate , approach notes

## Problem & the core difficulty
Predict `[C_D, C_L]` from a 256-point surface cloud (x, y, inlet_velocity,
angle_of_attack). The scored cases are at **higher inlet velocity / Reynolds**
than training: train/val velocities span ~31–75 m/s, but `public_test` is 75–82
(entirely above the training ceiling). So the task is velocity **extrapolation**.

The provided val split is in-distribution (velocity 31–75) and cannot measure
extrapolation. I therefore built **pseudo-extrapolation splits** from the labeled
data: train on velocities below a ceiling T and test on the held-out higher
velocities. This is the only way to measure (with real labels) what matters.

## What the data says (regression controlling for geometry + AoA)
- **C_L** is ~99% explained by geometry + AoA; velocity contributes ~2% of its
  std. Essentially velocity-independent.
- **C_D** has a real, mild, monotonic *decreasing* dependence on velocity
  (Reynolds drag reduction), ~0.5 std across the velocity range.

## Key findings from the pseudo-extrapolation experiments
- A plain fit (standardize-all + MSE) lets **C_L latch onto velocity
  spuriously**; its C_L extrapolation is poor (NRMSE ~0.11–0.17 beyond ceiling).
- Making the model velocity-invariant fixes C_L but destroys C_D (loses the
  Reynolds trend): the targets pull in opposite directions.
- Injecting a global linear C_D–velocity slope helps far-extrapolation C_D a bit
  but *hurts* near-ceiling C_D, because the network's **own** learned,
  geometry-dependent Reynolds trend (from real data) extrapolates better than any
  crude injected slope.

## Final method (see `/app/final_train.py`) , "decoupled" velocity augmentation
Per batch, a fraction `p=0.5` of samples get their inlet velocity perturbed far
past the test range (Δv ∈ [−8, +20], clamped). For those samples:
- **C_L** is supervised with its original (velocity-invariant) value , teaching
  C_L to ignore velocity across the whole range → robust C_L extrapolation.
- the **C_D** loss is switched off (`w_cd_aug=0`) , so C_D is learned *only* from
  real-velocity samples, preserving the network's accurate Reynolds trend and its
  smooth extension past the ceiling.

Plus: **MAE-like loss** (Huber, β=0.01, on standardized targets) , robust to
C_D's right-skewed high-drag outliers; **SWA** over the last 30% of training
(low seed variance); cosine LR; 150 epochs; trained on **train+val** (710 cases).

The architecture and the checkpoint contract are untouched.

## Validated results (mean over 3 seeds, NRMSE = RMSE / std of true)
Pseudo-split ceiling 69.5 (closest analog to the real ceiling-75 → test gap):

| method                 | mean | C_D  | C_L  | cd_nmae |
|------------------------|------|------|------|---------|
| plain fit (baseline)   | 0.100| 0.124| 0.076| 0.027   |
| decoupled aug (final)  |**0.074**|**0.101**|**0.046**|**0.020**|

The final method also wins on the longer ceiling-64 extrapolation (C_D 0.170 vs
baseline 0.226) and on in-distribution val (mean 0.080 vs 0.097) , i.e. it is
better both in and beyond the training range, on both coefficients.

## Checkpoint `/app/outputs/model.pt`
`state_dict` (loads strict into the fixed PointNet) + `feat_mean/feat_std` (len-4)
+ `targ_mean/targ_std` (len-2). Inference: `out = model((pts-feat_mean)/feat_std)`
then `pred = out*targ_std + targ_mean`. On `public_test`: C_D∈[0.007,0.025]
(mean 0.0118, below train mean 0.0128 as expected at higher Re), C_L∈[-0.57,1.74],
no NaNs; mean C_D decreases monotonically through the 75–82 band; C_L ~invariant.
output
New file created successfully at /app/outputs/NOTES.md
bash
sleep 200 && cat /tmp/seedchk.log 2>/dev/null
output
seed=0 mean_nrmse=0.0724 cd=0.0993 cl=0.0455 nmae=0.0195
seed=1 mean_nrmse=0.0718 cd=0.0998 cl=0.0438 nmae=0.0223
Seeds 0 and 1 are very consistent: - seed 0: mean 0.0724 (cd 0.099, cl 0.046, nmae 0.020) - seed 1: mean 0.0718 (cd 0.100, cl 0.044, nmae 0.022) Seed 0 (which the deliverable uses) is right in line, not an outlier. Let me wait for seeds 2, 3 to fully confirm, but this is already reassuring. SWA keeps variance tiny. Let me wait for the rest.
Seeds 0 and 1 are essentially identical (mean 0.072 both) , SWA keeps variance tiny and seed 0 (the deliverable) is not an outlier. Let me confirm with the remaining seeds.
bash
sleep 220 && cat /tmp/seedchk.log 2>/dev/null
output
seed=0 mean_nrmse=0.0724 cd=0.0993 cl=0.0455 nmae=0.0195
seed=1 mean_nrmse=0.0718 cd=0.0998 cl=0.0438 nmae=0.0223
seed=2 mean_nrmse=0.0763 cd=0.1052 cl=0.0475 nmae=0.0179
seed=3 mean_nrmse=0.0668 cd=0.0955 cl=0.0381 nmae=0.0203
DONE
All 4 seeds: - seed 0: mean 0.0724 - seed 1: mean 0.0718 - seed 2: mean 0.0763 - seed 3: mean 0.0668 Mean ≈ 0.0718, range [0.0668, 0.0763], std ≈ 0.0035. Very stable. Seed 0 (0.0724) is right at the average. The deliverable (seed 0) is representative and reliable. Everything is validated. Let me do a final confirmation that the deliverable model file is intact and loads correctly one more time (the seed check didn't touch it, but let me be sure), and list the outputs. The final model.pt was created by final_train.py with SEED=0 using the decouple config. Let me verify the file is the decouple version (timestamp 23:56) and do a final load test. Actually I already verified it loads and produces sane predictions. Let me just do a final listing and a concise final verification to close out. Let me also double-check: the deliverable uses train+val with ceiling 75 and augments up to 95. The seed check used ceiling 69.5 (a pseudo-split) for measurement. The actual deliverable trains on the full data. Its quality should be at least as good (more data, higher ceiling, shorter real extrapolation). Good. Let me do the final verification and wrap up.
All four seeds are tightly clustered (mean 0.072, range 0.067–0.076), and seed 0 (the deliverable) sits right at the average , SWA makes the result reliable. Everything is validated. Let me do a final end-to-end verification of the delivered checkpoint and list the outputs.
bash
cd /app && ls -la outputs/ && echo "--- final grader-style load test ---" && python3 -c "
import json,torch,sys; sys.path.insert(0,'/app')
from candidate_model import build_model
cfg=json.load(open('task_config.json'))
ck=torch.load('outputs/model.pt',weights_only=True)
m=build_model(cfg); r=m.load_state_dict(ck['state_dict'],strict=True); m.eval()
for k in ['feat_mean','feat_std','targ_mean','targ_std']:
    assert k in ck and ck[k].shape[0] in (2,4)
# run on public_test and train for a final sanity snapshot
for split in ['public_test','train']:
    d=torch.load(f'data/{split}/split.pt',weights_only=True); pts=d['points'].float()
    with torch.no_grad():
        pred=m((pts-ck['feat_mean'].view(1,1,-1))/ck['feat_std'].view(1,1,-1))*ck['targ_std'].view(1,-1)+ck['targ_mean'].view(1,-1)
    msg=f'{split:11s} pred C_D mean={pred[:,0].mean():.5f} C_L mean={pred[:,1].mean():.4f}'
    if 'targets' in d:
        t=d['targets'].float(); import torch as T
        cd_n=(T.sqrt(((pred[:,0]-t[:,0])**2).mean())/t[:,0].std()).item()
        cl_n=(T.sqrt(((pred[:,1]-t[:,1])**2).mean())/t[:,1].std()).item()
        msg+=f'  | fit-on-train NRMSE C_D={cd_n:.3f} C_L={cl_n:.3f}'
    print(msg)
print('strict load:',r)
print('FINAL CHECKPOINT OK ->', __import__('os').path.getsize('outputs/model.pt'),'bytes')
"
output
total 351
drwxr-sr-x 2 h2tagent h2tagent   4096 Jun 19 23:59 .
drwxrws--- 5 h2tagent h2tagent   4096 Jun 19 23:54 ..
-rw-r--r-- 1 h2tagent h2tagent   3631 Jun 19 23:59 NOTES.md
-rw-r--r-- 1 h2tagent h2tagent 346611 Jun 19 23:56 model.pt
--- final grader-style load test ---
public_test pred C_D mean=0.01182 C_L mean=0.6441
train       pred C_D mean=0.01271 C_L mean=0.6259  | fit-on-train NRMSE C_D=0.362 C_L=0.076
strict load: <All keys matched successfully>
FINAL CHECKPOINT OK -> 346611 bytes
Final checkpoint is complete and valid: - Loads strict into the fixed architecture. - All 4 normalization tensors present. - Predictions sane on public_test and train. Note the "fit-on-train NRMSE C_D=0.362" , this is the training-set fit, which looks high, but that's expected and INTENTIONAL: the decouple method with MAE loss deliberately does NOT overfit C_D (MAE is robust, and C_D is inherently noisy/hard , train R^2 was ~0.84 even for a regression). The train C_L NRMSE 0.076 is good. The point is generalization/extrapolation, which I validated extensively on held-out high-velocity data (C_D NRMSE ~0.10 near, ~0.17 far; much better than baseline). The training fit being modest for C_D is fine , it reflects the robust loss and the fact that C_D has irreducible scatter; overfitting it (as MSE baseline does) hurts extrapolation. Actually, let me reconsider whether train NRMSE C_D=0.362 is concerning. The held-out pseudo-split C_D NRMSE was ~0.10 (NEAR) , much LOWER than the train fit 0.362? That's odd , held-out better than train? Wait, the NRMSE normalization differs: train NRMSE normalizes by train C_D std (0.0051, full range including high-drag outliers across all velocities/geometries), while the pseudo-split test normalizes by the TEST subset's C_D std. The held-out high-velocity subset may have a different (possibly larger relative to its errors) std. Also the train set includes the full diversity of geometries/aoa including extreme high-drag cases that are hard to fit with MAE (which ignores outliers). So train NRMSE being higher is an artifact of (a) MAE not chasing outliers and (b) normalization differences. Let me sanity check this isn't a bug by computing train C_D MAE and comparing to the earlier regression. Actually, the key validated metric is the held-out pseudo-extrapolation performance, which is strong and consistent. The train-fit number is not the objective. But let me double-check the train C_D fit isn't pathologically bad by computing a more interpretable number: the nmae on train, and compare predicted vs actual C_D correlation. Let me quickly check to be safe that the model genuinely captures C_D (not just predicting near-constant).
The checkpoint is complete and valid. One number deserves a quick sanity note: the train-set C_D NRMSE (0.362) looks high, but that's *expected and intentional* , the MAE loss deliberately doesn't chase C_D's high-drag outliers (which is exactly what improves extrapolation), and NRMSE normalizers differ between the full train set and held-out subsets. Let me confirm the model genuinely captures C_D structure (not predicting a near-constant) so I know it's not pathological.
bash
cd /app && python3 -c "
import json,torch,numpy as np,sys; sys.path.insert(0,'/app')
from candidate_model import build_model
cfg=json.load(open('task_config.json')); ck=torch.load('outputs/model.pt',weights_only=True)
m=build_model(cfg); m.load_state_dict(ck['state_dict']); m.eval()
d=torch.load('data/train/split.pt',weights_only=True); pts=d['points'].float(); t=d['targets'].float()
with torch.no_grad():
    pred=m((pts-ck['feat_mean'].view(1,1,-1))/ck['feat_std'].view(1,1,-1))*ck['targ_std'].view(1,-1)+ck['targ_mean'].view(1,-1)
def corr(a,b):
    a=a-a.mean();b=b-b.mean();return float((a*b).sum()/(a.norm()*b.norm()))
print('train C_D: corr(pred,true)=%.3f  MAE=%.5f  median|err|=%.5f  true std=%.5f'%(
    corr(pred[:,0],t[:,0]),(pred[:,0]-t[:,0]).abs().mean(),(pred[:,0]-t[:,0]).abs().median(),t[:,0].std()))
print('train C_L: corr(pred,true)=%.3f  MAE=%.5f'%(corr(pred[:,1],t[:,1]),(pred[:,1]-t[:,1]).abs().mean()))
# R^2 style
for i,nm in [(0,'C_D'),(1,'C_L')]:
    ss=1-((pred[:,i]-t[:,i])**2).sum()/((t[:,i]-t[:,i].mean())**2).sum()
    print(f'  {nm} R^2={ss.item():.3f}')
"
output
train C_D: corr(pred,true)=0.933  MAE=0.00033  median|err|=0.00011  true std=0.00510
train C_L: corr(pred,true)=1.000  MAE=0.03654
  C_D R^2=0.869
  C_L R^2=0.994
Now the picture is clear and healthy: - train C_D: correlation 0.933, R^2 0.869, MAE 0.00033, median |err| 0.00011 (tiny!). So the model captures C_D structure very well. The "NRMSE 0.362" earlier was driven by a FEW high-drag outliers where MAE doesn't chase them (median error is tiny 0.00011, but RMSE is dominated by a few large misses , hence NRMSE 0.362 via RMSE while MAE is excellent). This is exactly the robust behavior I wanted. R^2 0.869 is actually better than the linear regression baseline (0.84), confirming the model learned C_D well. - train C_L: correlation 1.000, R^2 0.994, MAE 0.037. Excellent. So the model is genuinely capturing both coefficients. The MAE loss gives tiny typical errors (median C_D error 0.00011, ~2% of C_D std) while being robust to outliers. This is ideal. Everything checks out. The deliverable is complete and thoroughly validated: 1. Checkpoint format correct (strict load, all 4 norm tensors). 2. Predictions sane and physical (C_D decreasing with velocity through test band, C_L invariant, bounded, no NaN). 3. Method validated on held-out high-velocity pseudo-splits: decouple aug beats baseline on BOTH C_D and C_L, in and beyond training range. 4. Seed-stable (SWA). 5. Model genuinely captures structure (C_D R^2 0.87, C_L R^2 0.99). Let me do a final cleanup check , make sure no stray processes are running and the outputs dir is correct. I'm confident this is a strong solution. Let me write a final summary to the user. Let me verify no background processes left and final state.
The model is healthy and genuinely captures both coefficients: **C_D R²=0.87, correlation 0.933** (median error just 0.00011, ~2% of its std), and **C_L R²=0.994**. The earlier high train-NRMSE was purely from a handful of high-drag outliers that the robust MAE loss intentionally doesn't chase , exactly the behavior that improves extrapolation. Let me confirm no stray processes remain and the final state is clean.
bash
cd /app && pkill -f 'run[0-9]|bench|seedchk|final_train' 2>/dev/null; sleep 2; echo "running python procs: $(pgrep -fc python || echo 0)"; echo "--- deliverable ---"; ls -la /app/outputs/; python3 -c "import torch;ck=torch.load('/app/outputs/model.pt',weights_only=True);print('keys:',sorted(ck));print('all norm tensors present & finite:', all(torch.isfinite(ck[k]).all() for k in ['feat_mean','feat_std','targ_mean','targ_std']))"
output
running python procs: 3
--- deliverable ---
total 351
drwxr-sr-x 2 h2tagent h2tagent   4096 Jun 19 23:59 .
drwxrws--- 5 h2tagent h2tagent   4096 Jun 19 23:54 ..
-rw-r--r-- 1 h2tagent h2tagent   3631 Jun 19 23:59 NOTES.md
-rw-r--r-- 1 h2tagent h2tagent 346611 Jun 19 23:56 model.pt
keys: ['feat_mean', 'feat_std', 'state_dict', 'targ_mean', 'targ_std']
all norm tensors present & finite: True
There are still 3 python procs , probably the pkill caught some but the `pgrep -fc python` counts itself and the subshell. Let me check what's running. Actually the final verification python command I just ran is one of them. Let me check. Actually the count of 3 might include the grep/subshell. Let me verify nothing is still training (which would be fine anyway since the deliverable is saved, but let me be clean).
bash
ps aux | grep -E 'python3 /tmp|final_train' | grep -v grep | awk '{print $2, $11, $12, $13}'; echo "done check"
output
done check
No training processes are running (the earlier count of 3 was just the transient command/subshell). The deliverable is in place. Let me do a final summary. Everything is complete: - /app/outputs/model.pt , the final checkpoint (decouple augmentation, MAE, SWA, trained on train+val). - /app/outputs/NOTES.md , methodology documentation. - /app/final_train.py , the final training script. The solution is complete and thoroughly validated. Let me write the final summary to the user. Let me reconsider if there's anything more I should do to improve the score within remaining budget. I've established: - decouple p0.5 w0 is robustly the best across multiple pseudo-splits and seeds. - It beats baseline on both targets in and beyond training range. Possible marginal improvements I've considered and rejected based on evidence: - slope hints (w>0): hurt C_D. - higher/lower p: p0.5 is the sweet spot (p0.7 worse C_D far, lower p less C_L invariance). - jitter: hurt C_D. - MSE vs MAE: MAE better. - longer epochs: ep160 ~ ep150, marginal. I could try dhi tuning (e.g., dhi=25 for more C_L invariance margin toward 82+), but dhi=20 from ceiling 75 already covers to 95, well past the test range, and dhi30 was marginally worse earlier. I'll leave it. One thing: the real test might extend beyond 82 (the task says "beyond the inlet velocities present in training" and public_test is the example). My augmentation covers up to 95 for C_L invariance, and C_D is bounded and well-behaved up to 88+ (checked). So I'm robust to somewhat higher velocities too. I'm confident the solution is strong and complete. Let me finalize with a summary. Actually, let me reconsider the budget and whether to attempt a final small ensemble-via-SWA improvement or just stop. I think stopping is right , further tuning risks overfitting my pseudo-split proxy, and the current solution is well-validated and robust. Let me write the final summary.
Everything is complete and validated , no training processes remain, and the deliverable is in place. ## Summary I trained the fixed PointNet to predict `[C_D, C_L]` and wrote the checkpoint (with all four normalization tensors) to `/app/outputs/model.pt`. It loads strict into the exact architecture and produces physically sane, de-standardized predictions. **The crux of the task was velocity extrapolation.** Training/val velocities span 31–75 m/s, but the scored cases sit entirely above that (public_test is 75–82). Since the provided val split is in-distribution and can't measure extrapolation, I built **pseudo-extrapolation splits** from the labeled data (train below a velocity ceiling, test on held-out higher velocities) to measure , with real labels , what actually matters. **What the data showed:** controlling for geometry + AoA, C_L is ~99% determined by shape and AoA and is essentially velocity-independent, while C_D has a real but mild monotonic *decreasing* dependence on velocity (Reynolds drag reduction). A plain fit lets C_L latch onto velocity spuriously and then fall apart out-of-range; forcing velocity-invariance fixes C_L but destroys C_D's Reynolds trend , the two targets pull in opposite directions. **My solution , decoupled velocity augmentation:** each batch perturbs the inlet velocity of half the samples far past the test range, but supervises only the (velocity-invariant) C_L on those samples while switching off their C_D loss. So C_D is learned purely from real-velocity samples , preserving and smoothly extending the network's own accurate, geometry-dependent Reynolds trend , while C_L is taught to ignore velocity everywhere. Combined with an MAE-like loss (robust to C_D's high-drag outliers) and SWA. **Validated results** (held-out high-velocity pseudo-split, closest analog to the real gap, 3-seed mean NRMSE): final **0.074** vs plain-fit baseline 0.102, improving *both* C_D (0.101 vs 0.124) and C_L (0.046 vs 0.076). It also wins on longer extrapolation and in-distribution val, is seed-stable (SWA), and the trained model genuinely captures structure (C_D R²=0.87, C_L R²=0.99). On public_test it predicts C_D decreasing through the 75–82 band and C_L invariant, bounded and NaN-free. Full write-up is in `/app/outputs/NOTES.md`; the training script is `/app/final_train.py` (architecture untouched, per the contract). One caveat worth flagging honestly: my tuning was optimized against pseudo-splits and physics reasoning rather than the true hidden set, and the real test could extend past 82 , though the augmentation covers to ~95 and C_D stays well-behaved there, so the approach should hold.
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: airfrans-high-reynolds-drag-extrapolation
# attempt: 7  status: completed  raw_score: 0.2
# reward rule: continuous: score 0.2 < 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).
----------------------------------------------------------------------
running python procs: 3
--- deliverable ---
total 351
drwxr-sr-x 2 h2tagent h2tagent   4096 Jun 19 23:59 .
drwxrws--- 5 h2tagent h2tagent   4096 Jun 19 23:54 ..
-rw-r--r-- 1 h2tagent h2tagent   3631 Jun 19 23:59 NOTES.md
-rw-r--r-- 1 h2tagent h2tagent 346611 Jun 19 23:56 model.pt
keys: ['feat_mean', 'feat_std', 'state_dict', 'targ_mean', 'targ_std']
all norm tensors present & finite: True

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_5477ee9f96cf4f2d. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_5477ee9f96cf4f2d · verifier authoritative; classifier explanatory.