SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

adv-robust-pgd

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.
SubtypeImplementation Bugs
EvidenceComponent Conformance: 200/201 cases passed, with 1 failing case in autograd_grads (86/87); Final Metric: PGD robust accuracy 0.58 vs threshold 0.60. The verifier output states: 'failing milestones: autograd_grads (86/87)' and 'REWARD = 0 (1 iff every component milestone passes AND the sealed held-out metric clears its threshold)'. The agent came extremely close: 99.5% of component tests passed and 96.7% of robustness metric (0.58/0.60).
Root causeThe agent implemented a nearly-complete numpy deep learning framework but introduced a subtle bug in one of ~87 autograd gradient checks (likely in the conv2d input-gradient or a numerical stability issue) and their adversarial training strategy achieved 0.58 robust accuracy instead of the required 0.60. Both failures indicate implementation bugs rather than misunderstanding of the specification.
RecommendationN/A - task is fine. The instruction is explicit and comprehensive, listing every required operation, exact optimizer update math, and critical implementation details (stop-gradient for TRADES, col2im for conv input gradient). The task includes a public run_checks.py for incremental verification. This is a hard task with very high specification clarity; the agent's failure is due to implementation complexity, not underspecification.
Trajectory
Tool-by-tool agent trajectory
115 tool calls · 4 tool types · 136 steps
Agent session started, model: claude-opus-4-8 · 29 tools available · cwd: /app
I'll start by exploring the structure of the task.
shell
ls -la && echo "---SUBMISSION---" && ls -la submission/ && echo "---DATA---" && ls -la data/ && python3 -c "import numpy as np; d=np.load('data/train.npz'); print({k:(v.shape,v.dtype) for k,v in d.items()}); print('y range', d['y'].min(), d['y'].max(), 'classes', len(set(d['y'].tolist()))); print('X range', d['X'].min(), d['X'].max())"
output
total 101
drwxr-xr-x  4 user user  4096 Jun 30 22:15 .
drwxr-xr-x 21 root root  4096 Jun 30 22:15 ..
-rw-r--r--  1 user user 14238 Jun 30 22:15 PROMPT.txt
-rw-r--r--  1 user user     5 Jun 30 22:15 agent.pid
-rw-r--r--  1 user user     0 Jun 30 22:15 agent.stderr
-rw-r--r--  1 user user  4694 Jun 30 22:15 agent_trajectory.jsonl
drwxr-xr-x  2 user user    60 Jun 30 22:15 data
-rw-r--r--  1 user user     0 Jun 30 22:15 run.log
-rwxr-xr-x  1 user user 57740 Jun 30 11:01 run_checks.py
drwxr-xr-x  2 user user   128 Jun 30 22:15 submission
-rwxr-xr-x  1 user user   998 Jun 30 11:01 test.sh
-rwxr-xr-x  1 user user   629 Jun 30 11:01 timer.sh
---SUBMISSION---
total 80
drwxr-xr-x 2 user user   128 Jun 30 22:15 .
drwxr-xr-x 4 user user  4096 Jun 30 22:15 ..
-rw-r--r-- 1 user user  5490 Jun 30 11:01 advtrain.py
-rw-r--r-- 1 user user  8776 Jun 30 11:01 attack.py
-rw-r--r-- 1 user user 18341 Jun 30 11:01 autograd.py
-rw-r--r-- 1 user user  2167 Jun 30 11:01 data.py
-rw-r--r-- 1 user user 15988 Jun 30 11:01 nn.py
-rw-r--r-- 1 user user  8853 Jun 30 11:01 optim.py
-rw-r--r-- 1 user user  3742 Jun 30 11:01 train.py
---DATA---
total 2904
drwxr-xr-x 2 user user      60 Jun 30 22:15 .
drwxr-xr-x 4 user user    4096 Jun 30 22:15 ..
-rw-r--r-- 1 user user 2967336 Jun 30 11:01 train.npz
{'X': ((3600, 1, 16, 16), dtype('float32')), 'y': ((3600,), dtype('int64'))}
y range 0 5 classes 6
X range 0.0 1.0

/app/submission/autograd.py

contents
1	"""Reverse-mode automatic differentiation over numpy arrays (IMPLEMENT THIS).
2	
3	A ``Tensor`` wraps a single ``numpy.ndarray`` (``float64``) and records the operation that
4	produced it so that ``.backward()`` can walk the graph in reverse-topological order and
5	accumulate ``.grad`` (the gradient of the scalar on which ``.backward()`` was called w.r.t.
6	this tensor) into every leaf.
7	
8	This task is ADVERSARIAL ROBUSTNESS: the model is a small convolutional classifier and the
9	attacks (PGD/FGSM/MI-FGSM/PGD-L2/CW) ascend on the gradient of an attack loss w.r.t. the INPUT
10	image, so the autograd engine must (a) flow gradients back to PARAMETERS (for training) AND
11	(b) flow gradients back to the INPUT tensor (for the attack). BOTH directions are exercised by the
12	verifier's finite-difference gradient checks, so the convolution's input-gradient (the ``_col2im``
13	adjoint) is load-bearing.
14	
15	Contract (the verifier's conformance suite differentiates your analytic backward against finite
16	differences and checks your forward against its own reference, so match this exactly):
17	
18	* ``Tensor(data, requires_grad=False)`` -- ``data`` is array-like, stored as ``float64`` in
19	  ``self.data``; ``self.grad`` starts as ``None`` and becomes a same-shape ``float64`` array after
20	  backward. ``requires_grad`` leaves accumulate grad; non-requiring leaves do not.
21	* Every op returns a NEW ``Tensor`` whose ``requires_grad`` is the OR of its differentiable inputs.
22	 
…[truncated 18629 chars]

/app/submission/nn.py

contents
1	"""Neural-network layers + a small convolutional classifier, built on the autograd engine
2	(IMPLEMENT THE FORWARDS).
3	
4	Every module exposes ``params()`` -> list[Tensor] (the leaf tensors with ``requires_grad=True``)
5	and ``named_params()`` -> dict[str, Tensor] with STABLE names that match the checkpoint format the
6	verifier loads. ``SmallCNN.state_dict()`` / ``load_state_dict()`` round-trip a plain
7	``dict[str, np.ndarray]`` (saved as an ``.npz``); the verifier loads YOUR checkpoint into its OWN
8	reference SmallCNN via these names, so the names + shapes below are part of the contract.
9	
10	Naming contract for SmallCNN (do not change -- the verifier indexes by these exact keys):
11	  conv1.weight   (C1, C_in, 3, 3)        conv1.bias   (C1,)
12	  conv2.weight   (C2, C1, 3, 3)          conv2.bias   (C2,)
13	  fc1.weight     (C2*(H/4)*(W/4), F)      fc1.bias     (F,)
14	  fc2.weight     (F, n_classes)           fc2.bias     (n_classes,)
15	
16	Architecture (pinned): for an (N, C_in, H, W) input image batch,
17	  conv1 (C_in->C1, 3x3, pad 1) -> relu
18	  maxpool 2x2                   (H,W -> H/2,W/2)
19	  conv2 (C1->C2, 3x3, pad 1)   -> relu
20	  maxpool 2x2                   (H/2,W/2 -> H/4,W/4)
21	  flatten -> fc1 (-> F) -> relu -> fc2 (-> n_classes)   logits.
22	``Linear`` computes ``x @ weight + bias`` (weight is (in, out)). No BatchNorm inside SmallCNN (so
23	the attack runs a single deterministic eval-mode forward with no running-stat dependence).
24	
25	The other
…[truncated 15896 chars]

/app/submission/optim.py

contents
1	"""Optimizers + LR schedulers over a flat list of autograd ``Tensor`` parameters (IMPLEMENT THESE).
2	
3	Every optimizer operates IN PLACE on ``param.data`` using ``param.grad`` (the gradient accumulated
4	by ``Tensor.backward``). ``zero_grad()`` resets every grad to None. The EXACT update formula each
5	optimizer must match (the verifier checks one and several steps against its own reference) is in
6	its docstring.
7	
8	The adversarial-training loop uses AdamW (decoupled decay, with ``no_decay_ndim`` excluding 1-D
9	params/biases) + global grad-norm clipping; the rest of the optimizer zoo + the four LR schedulers
10	are part of the from-scratch framework the conformance suite audits.
11	"""
12	from __future__ import annotations
13	
14	import math
15	from typing import List
16	
17	import numpy as np
18	
19	from autograd import Tensor
20	
21	
22	class Optimizer:
23	    def __init__(self, params: List[Tensor]):
24	        self.params = list(params)
25	
26	    def zero_grad(self):
27	        for p in self.params:
28	            p.grad = None
29	
30	
31	class SGD(Optimizer):
32	    """SGD + momentum + optional Nesterov + (coupled/L2) weight decay:
33	        g = grad + wd*param;  v = mu*v + g;  step = (g + mu*v) if nesterov else v;  param -= lr*step."""
34	
35	    def __init__(self, params, lr=0.1, momentum=0.0, weight_decay=0.0, nesterov=False):
36	        super().__init__(params)
37	        self.lr = lr
38	        self.momentum = momentum
39	        self.weight_decay = weight
…[truncated 8125 chars]

/app/submission/attack.py

contents
1	"""White-box evasion attacks built on the from-scratch autograd engine (IMPLEMENT THESE).
2	
3	An adversary perturbs each input within a norm budget (L-inf eps in the [0,1] pixel domain by
4	default) and tries to make the classifier WRONG. Every attack ascends on the gradient of an attack
5	loss with respect to the INPUT image, which is exactly the gradient the autograd engine produces
6	when the input is wrapped in a ``requires_grad=True`` Tensor and the loss is backpropagated -- so a
7	correct ``conv2d`` input-gradient (the ``_col2im`` adjoint) is load-bearing.
8	
9	THE PRIMITIVE
10	  input_grad(model, x, y)                  d/dx of mean cross-entropy of model(x) vs y (ndarray).
11	  loss_input_grad(model, x, y, loss_fn)    d/dx of an ARBITRARY scalar attack loss loss_fn(logits,y).
12	
13	L-INF ATTACKS
14	  fgsm(model, x, y, eps)                    clip(x + eps*sign(input_grad)).
15	  pgd_attack(model, x, y, eps, steps, alpha)  iterated FGSM with random start + project to the
16	                                            L-inf eps-ball around x AND the [0,1] box each step.
17	  mi_fgsm(model, x, y, eps, steps, alpha, mu) momentum-iterative FGSM: accumulate a decaying
18	                                            momentum of the L1-NORMALIZED gradient, step on its sign,
19	                                            project each step.
20	  targeted_pgd(model, x, y_target, eps, steps, alpha)  DESCEND CE toward y_target (step on the
21	                                     
…[truncated 7820 chars]

/app/submission/advtrain.py

contents
1	"""Adversarial-training objectives built on the from-scratch autograd engine (IMPLEMENT THESE).
2	
3	Several standard recipes turn a fragile classifier into a robust one. Each crafts adversarial
4	inputs per minibatch with the model's own attack, then takes a gradient step on a robustness-aware
5	loss; the recipes differ in the loss. All run a single forward+backward; the caller does grad-clip
6	+ the optimizer step. ``x_clean`` / ``x_adv`` are ndarrays (N, C, H, W); ``y`` is an int (N,).
7	
8	  pgd_at_loss(model, x_adv, y)                  Madry PGD-AT: CE on the ADVERSARIAL batch.
9	  trades_loss(model, x_clean, x_adv, y, beta)   TRADES: CE(clean) + beta*KL(stopgrad(clean)||adv).
10	                                                The clean branch INSIDE the KL is a STOP-GRADIENT
11	                                                target (detached): the KL backprops only through
12	                                                the adversarial branch.
13	  mart_loss(model, x_clean, x_adv, y, beta)     MART: boosted-CE on the adversarial batch
14	                                                ( CE(adv,y) - mean log(1 - max_{j!=y} p_adv_j) ) +
15	                                                beta * mean_i[ (1 - p_clean_i[y_i]) *
16	                                                KL_i(softmax(adv)||stopgrad softmax(clean)) ].
17	  alp_loss(model, x_clean, x_adv, y, lam)       Adversarial Logit Pairing:
18	                                                0.5*(CE(clean)+CE(ad
…[truncated 4278 chars]

/app/submission/data.py

contents
1	"""Data loading + minibatching for the shape-classification set (IMPLEMENT THESE).
2	
3	The visible train split ships as ``/app/data/train.npz`` with arrays ``X`` (N, C, H, W) float
4	pixels in [0,1] and ``y`` (N,) int labels. The SEALED held-out split is NOT in the image -- the
5	verifier regenerates it from a secret feature seed and runs its own attack on it.
6	
7	Contract:
8	  load_npz(path) -> (X float64 (N,C,H,W), y int64 (N,))
9	  train_val_split(X, y, val_frac, rng) -> ((Xtr,ytr),(Xval,yval))   random disjoint split (val slice
10	        is a held-BACK slice of the VISIBLE train data you may use for best-checkpoint selection --
11	        it is NOT the verifier's sealed held-out set)
12	  iter_batches(X, y, batch_size, rng) -> yields (xb, yb) random-permutation minibatches
13	  get_batch(X, y, batch_size, rng) -> a single random minibatch
14	  to_onehot(y, n_classes) -> (N, n_classes) one-hot float matrix
15	  clip01(X) -> X clamped into the [0,1] pixel domain
16	"""
17	from __future__ import annotations
18	
19	from typing import Iterator, Tuple
20	
21	import numpy as np
22	
23	
24	def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
25	    raise NotImplementedError("implement load_npz")
26	
27	
28	def train_val_split(X: np.ndarray, y: np.ndarray, val_frac: float,
29	                    rng: np.random.Generator):
30	    raise NotImplementedError("implement train_val_split")
31	
32	
33	def iter_batches(X: np.ndarray, y: np.ndarray, batch_size: int,
34	           
…[truncated 814 chars]

/app/submission/train.py

contents
1	"""Adversarial-training loop for the small CNN, using the from-scratch numpy framework
2	(IMPLEMENT THIS).
3	
4	Standard (clean) training reaches ~99% CLEAN accuracy but ~chance ROBUST accuracy -- it is broken
5	by the verifier's STRONG multi-restart L-inf PGD attack. WEAK robust training is not enough either:
6	single-step (FGSM) adversarial training suffers "catastrophic overfitting" and is shattered by the
7	multi-step / multi-restart eval attack, and adversarial training at a SMALLER perturbation budget
8	than the eval budget leaves the model fragile exactly where it is attacked. The effective recipe is
9	full multi-step PGD ADVERSARIAL TRAINING (Madry et al. 2018) with the perturbation budget MATCHED
10	to the (larger) eval budget:
11	
12	  * on every minibatch, craft an inner k-step L-inf PGD adversarial batch against the CURRENT model
13	    (attack.pgd_attack), at the eps the eval uses, then take the AdamW step on advtrain.pgd_at_loss
14	    (cross-entropy on the adversarial batch);
15	  * train long enough for robustness to converge (a few epochs is not enough at this eps);
16	  * stability details that materially raise the achieved robust accuracy and make it reproducible:
17	    (a) exclude biases (1-D params) from weight decay (AdamW no_decay_ndim=1); (b) clip the global
18	    gradient norm (the adversarial loss surface is sharp); (c) keep the BEST-by-robust-accuracy
19	    checkpoint, evaluated each epoch with the model's own multi-step PGD on a held-BACK slic
…[truncated 2473 chars]
Now let me examine the public check runner to understand exact API expectations, especially the stop-gradient mechanism.
shell
wc -l run_checks.py && grep -n "detach\|stop_grad\|stopgrad\|\.detach\|requires_grad" run_checks.py | head -50
output
1187 run_checks.py
139:            t = T(x0.copy(), requires_grad=True)
217:        lt = T(x0.copy(), requires_grad=True)
226:        lt = T(x0.copy(), requires_grad=True)
235:        lt = T(x0.copy(), requires_grad=True)
244:        lt = T(x0.copy(), requires_grad=True)
253:        wt = T(w0.copy(), requires_grad=True)
263:        lt = T(x0.copy(), requires_grad=True)
274:            pt = T(p0.copy(), requires_grad=True)
279:            qt = T(q0.copy(), requires_grad=True)
290:            xt = T(x.copy(), requires_grad=True)
295:            Wt = T(W.copy(), requires_grad=True)
300:            bt = T(b.copy(), requires_grad=True)
312:        xt = T(x0.copy(), requires_grad=True)
323:        xt = T(x0.copy(), requires_grad=True)
352:        xt = T(x0.copy(), requires_grad=True)
421:        xt = T(x0.copy(), requires_grad=True)
596:        return [T(rng.standard_normal(s), requires_grad=True) for s in shapes]
872:        lt = ag.Tensor(x0.copy(), requires_grad=True)
970:        lt = ag.Tensor(x0.copy(), requires_grad=True)
976:    # TRADES stop-gradient: agent TRADES grad must equal a hand-built detached-target reference.
977:    def trades_stopgrad():
990:    prop("trades_stopgrad", trades_stopgrad)
1009:    # CLP stop-gradient (pairing target detached): agent CLP grad equals a detached-target reference.
1010:    def clp_stopgrad():
1025:    prop("clp_stopgrad", clp_stopgrad)
1027:    # KL-AT stop-gradient + adv-as-p argument order: agent grad equals the detached-target refer
…[truncated 84 chars]

/app/run_checks.py

contents
960	    prop("alp_param_grad", lambda: param_grad("alp", lambda m: at.alp_loss(m, Xc, Xa, y, lam=0.7), "conv2.weight", 64))
961	    prop("robust_ce_param_grad", lambda: param_grad("rce", lambda m: at.robust_ce_loss(m, Xc, Xa, y, lam=0.5), "fc2.weight", 65))
962	    prop("clp_param_grad", lambda: param_grad("clp", lambda m: at.clp_loss(m, Xc, Xa, y, lam=0.7), "fc1.weight", 80))
963	    prop("kl_at_param_grad", lambda: param_grad("klat", lambda m: at.kl_at_loss(m, Xc, Xa, y, beta=6.0), "conv2.weight", 81))
964	    prop("logit_squeeze_param_grad", lambda: param_grad("lsq", lambda m: at.logit_squeeze_at_loss(m, Xa, y, lam=1e-2), "fc2.weight", 82))
965	    prop("ls_at_param_grad", lambda: param_grad("lsat", lambda m: at.ls_at_loss(m, Xa, y, eps_ls=0.1), "fc1.weight", 83))
966	
967	    def ls_ce_grad():
968	        rng2 = np.random.default_rng(sb + 66)
969	        x0 = rng2.standard_normal((5, 4)); tgt = rng2.integers(0, 4, size=5)
970	        lt = ag.Tensor(x0.copy(), requires_grad=True)
971	        at.label_smoothed_ce(lt, tgt, 0.1).backward()
972	        gnum = _num_grad_input(lambda xv: np.array(float(at.label_smoothed_ce(ag.Tensor(xv), tgt, 0.1).data)), x0.copy())
973	        return _max_abs(lt.grad, gnum) < TOL_GRAD, ""
974	    prop("label_smoothed_ce_grad", ls_ce_grad)
975	
976	    # TRADES stop-gradient: agent TRADES grad must equal a hand-built detached-target reference.
977	    def trades_stopgrad():
978	        m = _m(71); key = "fc1.weight"; beta = 5.0
979	        for p
…[truncated 5435 chars]

/app/run_checks.py

contents
1	#!/usr/bin/env python3
2	"""PUBLIC component check runner for the from-scratch numpy framework + the adversarial machinery.
3	
4	Run this AS OFTEN AS YOU LIKE while you implement to get a per-check progress signal:
5	
6	    python3 /app/run_checks.py                       # check the framework in /app/submission
7	    python3 /app/run_checks.py --submission /some/dir
8	    python3 /app/run_checks.py --only attack         # focus a single milestone
9	
10	It imports YOUR modules from /app/submission (autograd.py / nn.py / optim.py / data.py / attack.py
11	/ advtrain.py), exactly as the grader does, and runs a PUBLIC portion of the component conformance
12	suite, printing a clear per-check report. Each FAIL line names the exact op / layer / optimizer /
13	attack / adversarial-training property that is wrong.
14	
15	HOW THIS RELATES TO YOUR GRADE
16	------------------------------
17	This runner is a DEBUGGING AID, not the grader. It checks YOUR framework against self-consistent
18	references it computes on its OWN:
19	  * autograd_grads : central FINITE-DIFFERENCE of YOUR forward vs YOUR analytic backward (every op,
20	                     incl. the convolution input-gradient, the pools, and the full SmallCNN -- both
21	                     grad-wrt-PARAMS and grad-wrt-INPUT, the attack gradient).
22	  * nn_forward     : mathematical PROPERTIES your forward must satisfy (relu/softmax/conv arithmetic
23	                     /SmallCNN shape).
24	  * optim          : YOUR optimize
…[truncated 4027 chars]

/app/run_checks.py

contents
130	    ag = fw["autograd"]
131	    nn = fw["nn"]
132	    T = ag.Tensor
133	    results = []
134	
135	    def case(name, build, shape, seed, fdfun=None):
136	        try:
137	            rng = np.random.default_rng(sb + seed)
138	            x0 = rng.standard_normal(shape)
139	            t = T(x0.copy(), requires_grad=True)
140	            ag.sum(build(t)).backward()
141	            gan = np.asarray(t.grad, np.float64)
142	            ffun = fdfun or (lambda xv: build(T(xv)).data)
143	            gnum = _num_grad_input(ffun, x0.copy())
144	            err = _max_abs(gan, gnum)
145	            results.append((f"grad/{name}", err < TOL_GRAD, f"max_abs={err:.2e}"))
146	        except Exception as e:  # noqa: BLE001
147	            results.append((f"grad/{name}", False, f"raised {type(e).__name__}: {e}"))
148	
149	    def guard(name, fn):
150	        try:
151	            fn()
152	        except Exception as e:  # noqa: BLE001
153	            results.append((f"grad/{name}", False, f"raised {type(e).__name__}: {e}"))
154	
155	    case("add_bcast", lambda t: ag.add(t, T(np.arange(t.shape[-1], dtype=float) + 1.0)), (4, 5), 1)
156	    case("sub_bcast", lambda t: ag.sub(t, T(np.arange(t.shape[-1], dtype=float) + 1.0)), (4, 5), 2)
157	    case("mul_bcast", lambda t: ag.mul(t, T(np.arange(t.shape[-1], dtype=float) + 1.0)), (4, 5), 3)
158	    case("div", lambda t: ag.div(t, T(np.full((4, 5), 2.0))), (4, 5), 4)
159	    case("power3", lambda t: ag.power(t, 3.0), (4, 5), 5)
160	    case("ma
…[truncated 17325 chars]

/app/run_checks.py

contents
449	
450	    def leaky_def():
451	        x = np.random.default_rng(sb + 2).standard_normal((4, 5))
452	        return _max_abs(ag.leaky_relu(T(x), 0.1).data, np.where(x > 0, x, 0.1 * x)) < TOL_PROP, ""
453	
454	    def sigmoid_def():
455	        x = np.random.default_rng(sb + 3).standard_normal((4, 5))
456	        return _max_abs(ag.sigmoid(T(x)).data, 1.0 / (1.0 + np.exp(-x))) < TOL_PROP, ""
457	
458	    def tanh_def():
459	        x = np.random.default_rng(sb + 4).standard_normal((4, 5))
460	        return _max_abs(ag.tanh(T(x)).data, np.tanh(x)) < TOL_PROP, ""
461	
462	    def gelu_def():
463	        x = np.random.default_rng(sb + 5).standard_normal((4, 5))
464	        return _max_abs(ag.gelu(T(x)).data, x * 0.5 * (1.0 + erf(x / np.sqrt(2.0)))) < 1e-6, ""
465	
466	    def softmax_rows():
467	        x = np.random.default_rng(sb + 6).standard_normal((4, 5))
468	        s = ag.softmax(T(x)).data
469	        return abs(s.sum(axis=-1) - 1.0).max() < 1e-9 and (s >= 0).all(), ""
470	
471	    def ce_value():
472	        x = np.random.default_rng(sb + 7).standard_normal((5, 4)); tgt = np.array([0, 1, 2, 3, 0])
473	        logp = x - np.log(np.exp(x - x.max(-1, keepdims=True)).sum(-1, keepdims=True)) - x.max(-1, keepdims=True)
474	        ref = float(-logp[np.arange(5), tgt].mean())
475	        return abs(float(ag.cross_entropy(T(x), tgt).data) - ref) < 1e-6, ""
476	
477	    def kl_nonneg():
478	        x = np.random.default_rng(sb + 8).standard_normal((4, 5))
479	        return f
…[truncated 11937 chars]

/app/run_checks.py

contents
729	        lion_step(1e-3, 0.9, 0.99, 0.05), 8, sb + 10, SH)
730	    run("Adadelta_8step", lambda p: opt.Adadelta(p, lr=1.0, rho=0.9, weight_decay=1e-3),
731	        adadelta_step(1.0, 0.9, 1e-6, 1e-3), 8, sb + 11, SH)
732	
733	    def clip_norm_case(name, scale_in, max_norm):
734	        try:
735	            ps = mk(sb + 600, [(4, 3), (3,)])
736	            grng = np.random.default_rng(sb + 12)
737	            gs = [grng.standard_normal(p.data.shape) * scale_in for p in ps]
738	            for p, g in zip(ps, gs):
739	                p.grad = g.copy()
740	            opt.clip_grad_norm(ps, max_norm)
741	            total = float(np.sqrt(sum(float((g ** 2).sum()) for g in gs)))
742	            ref = [g * (max_norm / (total + 1e-6)) if total > max_norm else g for g in gs]
743	            err = max(_max_abs(p.grad, ref[i]) for i, p in enumerate(ps))
744	            results.append((f"optim/{name}", err < TOL_OPT, f"max_abs={err:.1e}"))
745	        except Exception as e:  # noqa: BLE001
746	            results.append((f"optim/{name}", False, f"raised {type(e).__name__}: {e}"))
747	    clip_norm_case("clip_grad_norm_clips", 10.0, 1.0)
748	    clip_norm_case("clip_grad_norm_noop", 0.01, 1.0)
749	
750	    def clip_value_case():
751	        try:
752	            ps = mk(sb + 610, [(4, 3), (3,)])
753	            grng = np.random.default_rng(sb + 13)
754	            gs = [grng.standard_normal(p.data.shape) * 3.0 for p in ps]
755	            for p, g in zip(ps, gs):
756	                
…[truncated 7384 chars]

/app/run_checks.py

contents
888	        xf = atk.fgsm(m, x, y, eps); xb = atk.bim(m, x, y, eps, 15, 0.025)
889	        lf = float(ag.cross_entropy(m(xf), y).data); lb = float(ag.cross_entropy(m(xb), y).data)
890	        return lb >= lf - 1e-6, f"fgsm={lf:.3f} bim={lb:.3f}"
891	
892	    def restarts_worst_case():
893	        m = _model(69)
894	        x = np.clip(np.random.default_rng(sb + 70).random((8, 1, 8, 8)), 0, 1); y = np.array([0, 1, 2, 3, 0, 1, 2, 3]); eps = 0.12
895	        x1 = atk.pgd_attack(m, x, y, eps, 10, 0.03, rng=np.random.default_rng(sb + 71))
896	        xr = atk.pgd_restarts(m, x, y, eps, 10, 0.03, restarts=4, rng=np.random.default_rng(sb + 72))
897	        l1 = float(ag.cross_entropy(m(x1), y).data); lr = float(ag.cross_entropy(m(xr), y).data)
898	        return lr >= l1 - 1e-6, f"single={l1:.3f} restarts={lr:.3f}"
899	
900	    prop("input_grad_fd", input_grad_fd)
901	    prop("cw_loss_input_grad_fd", cw_input_grad_fd)
902	    prop("dlr_loss_grad", dlr_loss_grad)
903	    prop("dlr_loss_input_grad_fd", dlr_input_grad_fd)
904	    prop("fgsm_step", fgsm_step)
905	    prop("pgd_projection", lambda: proj("pgd", lambda m, x, y, e: atk.pgd_attack(m, x, y, e, 10, 0.03, rng=np.random.default_rng(sb + 22)), 0.1))
906	    prop("mi_fgsm_projection", lambda: proj("mi", lambda m, x, y, e: atk.mi_fgsm(m, x, y, e, 10, 0.03, mu=1.0, rng=np.random.default_rng(sb + 23)), 0.1))
907	    prop("cw_pgd_projection", lambda: proj("cw", lambda m, x, y, e: atk.cw_pgd(m, x, y, e, 10, 0.03, rng=np.random.default
…[truncated 4366 chars]
shell
grep -n "def check_data\|mart\|p_clean\|max_{j" run_checks.py | head; sed -n '1080,1187p' run_checks.py
output
28:  * advtrain       : pgd_at / trades / mart / alp / robust_ce / label_smoothed_ce forward+grad
959:    prop("mart_param_grad", lambda: param_grad("mart", lambda m: at.mart_loss(m, Xc, Xa, y, beta=5.0), "fc1.weight", 63))
1089:def check_data(fw, sb):

    run("pgd_at", "at")
    run("trades", "trades")

    npass = builtin_sum(1 for _, ok, _ in results if ok)
    return npass, len(results), results


# ======================================================================= data (smoke)
def check_data(fw, sb):
    data = fw["data"]
    results = []

    def prop(name, fn):
        try:
            ok, info = fn()
            results.append((f"data/{name}", ok, info))
        except Exception as e:  # noqa: BLE001
            results.append((f"data/{name}", False, f"raised {type(e).__name__}: {e}"))

    def batch_shape():
        rng = np.random.default_rng(sb)
        X = rng.standard_normal((50, 1, 8, 8)); y = rng.integers(0, 4, 50)
        bx, by = data.get_batch(X, y, 16, rng)
        return bx.shape == (16, 1, 8, 8) and by.shape == (16,), f"{bx.shape},{by.shape}"

    def split_shape():
        rng = np.random.default_rng(sb + 1)
        X = rng.standard_normal((40, 1, 8, 8)); y = rng.integers(0, 4, 40)
        (Xtr, ytr), (Xval, yval) = data.train_val_split(X, y, 0.25, rng)
        return len(Xtr) + len(Xval) == 40 and len(Xval) == 10, f"{len(Xtr)}/{len(Xval)}"

    def onehot():
        oh = data.to_onehot(np.array([0, 2, 1]), 3)
        return oh.shape == (3, 3) and 
…[truncated 2840 chars]
Now I have a thorough understanding. Let me create a task list and start implementing `autograd.py`.
write · /app/submission/autograd.py
"""Reverse-mode automatic differentiation over numpy arrays."""
from __future__ import annotations

import math
from typing import Callable, Iterable, List, Optional

import numpy as np

_erf = np.vectorize(math.erf)
_SQRT2 = math.sqrt(2.0)
_SQRT2PI = math.sqrt(2.0 * math.pi)


def _as_f64(x) -> np.ndarray:
    return np.asarray(x, dtype=np.float64)


def _unbroadcast(grad: np.ndarray, shape: tuple) -> np.ndarray:
    grad = np.asarray(grad, dtype=np.float64)
    while grad.ndim > len(shape):
        grad = grad.sum(axis=0)
    for i, s in enumerate(shape):
        if s == 1 and grad.shape[i] != 1:
            grad = grad.sum(axis=i, keepdims=True)
    return grad


def _expand(g, shape, axis, keepdims):
    """Broadcast a reduced gradient ``g`` back to ``shape`` (axis can be None/int/tuple)."""
    g = np.asarray(g, dtype=np.float64)
    if axis is None:
        return np.broadcast_to(g, shape)
    if not keepdims:
        ax = axis if isinstance(axis, tuple) else (axis,)
        ax = tuple(a % len(shape) for a in ax)
        g = np.expand_dims(g, ax)
    return np.broadcast_to(g, shape)


def _count(shape, axis):
    if axis is None:
        n = 1
        for s in shape:
            n *= s
        return n
    ax = axis if isinstance(axis, tuple) else (axis,)
    n = 1
    for a in ax:
        n *= shape[a]
    return n


class Tensor:
    __slots__ = ("data", "grad", "requires_grad", "_backward", "_parents")

    def __init__(self, data, requires_grad: bool = False, _paren
…[truncated 27580 chars]

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Let me clean up the `maximum` backward which I wrote awkwardly:

/app/submission/autograd.py

− removed
    def bw():
        g = out.grad
        sa = np.where(a.data > b.data, 1.0, np.where(a.data == b.data, 0.5, 0.0))
        if a.requires_grad:
            a._accum(_unbroadcast(g * sa, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(g * (1.0 - sa) if False else g * np.where(b.data > a.data, 1.0, np.where(a.data == b.data, 0.5, 0.0)), b.data.shape))
    out._backward = bw
    return out


def minimum(a, b) -> Tensor:
+ added
    def bw():
        g = out.grad
        sa = np.where(a.data > b.data, 1.0, np.where(a.data == b.data, 0.5, 0.0))
        sb = np.where(b.data > a.data, 1.0, np.where(a.data == b.data, 0.5, 0.0))
        if a.requires_grad:
            a._accum(_unbroadcast(g * sa, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(g * sb, b.data.shape))
    out._backward = bw
    return out


def minimum(a, b) -> Tensor:

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now `nn.py`. Let me implement all the forwards:

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.conv2d(x, weight, bias, pad)."""
        raise NotImplementedError("implement Conv2d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.conv2d(x, weight, bias, pad)."""
        return ag.conv2d(x, self.weight, self.bias, pad=self.pad)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.maxpool2d(x, k)."""
        raise NotImplementedError("implement MaxPool2d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.maxpool2d(x, k)."""
        return ag.maxpool2d(x, self.k)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.avgpool2d(x, k)."""
        raise NotImplementedError("implement AvgPool2d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.avgpool2d(x, k)."""
        return ag.avgpool2d(x, self.k)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.matmul(x, weight) + bias."""
        raise NotImplementedError("implement Linear.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.matmul(x, weight) + bias."""
        return ag.add(ag.matmul(x, self.weight), self.bias)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.layernorm(x, weight, bias, eps)."""
        raise NotImplementedError("implement LayerNorm.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.layernorm(x, weight, bias, eps)."""
        return ag.layernorm(x, self.weight, self.bias, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.batchnorm(x, weight, bias, eps)."""
        raise NotImplementedError("implement BatchNorm1d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.batchnorm(x, weight, bias, eps)."""
        return ag.batchnorm(x, self.weight, self.bias, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x):
        """linear -> relu (between layers) -> ... -> linear (no final activation)."""
        raise NotImplementedError("implement MLP.forward")
+ added
    def forward(self, x):
        """linear -> relu (between layers) -> ... -> linear (no final activation)."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        for i, lin in enumerate(self.layers):
            x = lin(x)
            if i < len(self.layers) - 1:
                x = ag.relu(x)
        return x

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x):
        """for each conv: pool(relu(conv(x))); then flatten -> relu(fc1) -> fc2."""
        raise NotImplementedError("implement ConvNet.forward")
+ added
    def forward(self, x):
        """for each conv: pool(relu(conv(x))); then flatten -> relu(fc1) -> fc2."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        for conv in self.convs:
            x = self.pool(ag.relu(conv(x)))
        n = x.shape[0]
        x = ag.reshape(x, (n, -1))
        x = ag.relu(self.fc1(x))
        return self.fc2(x)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.groupnorm(x, weight, bias, num_groups, eps)."""
        raise NotImplementedError("implement GroupNorm.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.groupnorm(x, weight, bias, num_groups, eps)."""
        return ag.groupnorm(x, self.weight, self.bias, self.num_groups, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.rmsnorm(x, weight, eps)."""
        raise NotImplementedError("implement RMSNorm.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.rmsnorm(x, weight, eps)."""
        return ag.rmsnorm(x, self.weight, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """h' = tanh(x @ weight_ih^T + bias_ih + h @ weight_hh^T + bias_hh)."""
        raise NotImplementedError("implement RNNCell.forward")
+ added
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """h' = tanh(x @ weight_ih^T + bias_ih + h @ weight_hh^T + bias_hh)."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        if not isinstance(h, Tensor):
            h = Tensor(h)
        ih = ag.add(ag.matmul(x, ag.transpose(self.weight_ih)), self.bias_ih)
        hh = ag.add(ag.matmul(h, ag.transpose(self.weight_hh)), self.bias_hh)
        return ag.tanh(ag.add(ih, hh))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """the GRU update above (slice the 3 gates out of the (N,3H) pre-activations)."""
        raise NotImplementedError("implement GRUCell.forward")
+ added
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """the GRU update above (slice the 3 gates out of the (N,3H) pre-activations)."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        if not isinstance(h, Tensor):
            h = Tensor(h)
        H = self.hidden_size
        gi = ag.add(ag.matmul(x, ag.transpose(self.weight_ih)), self.bias_ih)  # (N,3H)
        gh = ag.add(ag.matmul(h, ag.transpose(self.weight_hh)), self.bias_hh)  # (N,3H)
        i_r, i_z, i_n = gi[:, 0:H], gi[:, H:2 * H], gi[:, 2 * H:3 * H]
        h_r, h_z, h_n = gh[:, 0:H], gh[:, H:2 * H], gh[:, 2 * H:3 * H]
        r = ag.sigmoid(ag.add(i_r, h_r))
        z = ag.sigmoid(ag.add(i_z, h_z))
        n = ag.tanh(ag.add(i_n, ag.mul(r, h_n)))
        one_minus_z = ag.sub(1.0, z)
        return ag.add(ag.mul(one_minus_z, n), ag.mul(z, h))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor, h: Tensor, c: Tensor):
        """the LSTM update above; return (h', c')."""
        raise NotImplementedError("implement LSTMCell.forward")
+ added
    def forward(self, x: Tensor, h: Tensor, c: Tensor):
        """the LSTM update above; return (h', c')."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        if not isinstance(h, Tensor):
            h = Tensor(h)
        if not isinstance(c, Tensor):
            c = Tensor(c)
        H = self.hidden_size
        g = ag.add(ag.add(ag.matmul(x, ag.transpose(self.weight_ih)), self.bias_ih),
                   ag.add(ag.matmul(h, ag.transpose(self.weight_hh)), self.bias_hh))  # (N,4H)
        i = ag.sigmoid(g[:, 0:H])
        f = ag.sigmoid(g[:, H:2 * H])
        gg = ag.tanh(g[:, 2 * H:3 * H])
        o = ag.sigmoid(g[:, 3 * H:4 * H])
        c2 = ag.add(ag.mul(f, c), ag.mul(i, gg))
        h2 = ag.mul(o, ag.tanh(c2))
        return h2, c2

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x):
        """h = pool(relu(conv1(x))); res = conv2b(relu(conv2a(h))); h = relu(h + res); flatten -> fc."""
        raise NotImplementedError("implement SmallResCNN.forward")
+ added
    def forward(self, x):
        """h = pool(relu(conv1(x))); res = conv2b(relu(conv2a(h))); h = relu(h + res); flatten -> fc."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        h = self.pool(ag.relu(self.conv1(x)))
        res = self.conv2b(ag.relu(self.conv2a(h)))
        h = ag.relu(ag.add(h, res))
        n = h.shape[0]
        h = ag.reshape(h, (n, -1))
        return self.fc(h)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x) -> Tensor:
        """conv1 -> relu -> pool -> conv2 -> relu -> pool -> flatten -> fc1 -> relu -> fc2."""
        raise NotImplementedError("implement SmallCNN.forward")
+ added
    def forward(self, x) -> Tensor:
        """conv1 -> relu -> pool -> conv2 -> relu -> pool -> flatten -> fc1 -> relu -> fc2."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        x = self.pool(ag.relu(self.conv1(x)))
        x = self.pool(ag.relu(self.conv2(x)))
        n = x.shape[0]
        x = ag.reshape(x, (n, -1))
        x = ag.relu(self.fc1(x))
        return self.fc2(x)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now let me run the autograd and nn_forward checks:
shell
python3 run_checks.py --only autograd_grads 2>&1 | tail -40
output
grad/prod_axis                           OK    (max_abs=5.65e-10)
  grad/cumsum_ax1                          OK    (max_abs=3.79e-11)
  grad/logsumexp_ax1                       OK    (max_abs=4.93e-11)
  grad/pad2d                               OK    (max_abs=5.10e-11)
  grad/groupnorm_x                         OK  
  grad/rmsnorm_x                           OK  
  grad/layernorm_x                         OK  
  grad/batchnorm_x                         OK  
  grad/embedding                           OK  
  grad/mse_loss                            OK  
  grad/cross_entropy                       OK  
  grad/kl_div_q                            OK  
  grad/kl_div_p                            OK  
  grad/conv2d_input                        OK    (max_abs=1.09e-09)
  grad/conv2d_weight                       OK    (max_abs=3.38e-09)
  grad/conv2d_bias                         OK  
  grad/conv2d_pad0_input                   OK    (max_abs=7.79e-10)
  grad/maxpool2d                           OK  
  grad/avgpool2d                           OK  
  grad/nn.Conv2d_x                         OK  
  grad/nn.Linear_x                         OK  
  grad/nn.LayerNorm_x                      OK  
  grad/nn.BatchNorm1d_x                    OK  
  grad/cnn_grad_fc2.bias                   OK    (max_abs=1.21e-11)
  grad/cnn_grad_conv1.weight               OK    (max_abs=2.55e-11)
  grad/cnn_grad_conv2.weight               OK    (max_abs=2.61e-11)
  grad/cnn_grad_fc1.weight                 OK    (ma
…[truncated 815 chars]
Excellent! All autograd grads pass. Now optim and the rest:

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement SGD.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._v[i] = self.momentum * self._v[i] + g
            v = self._v[i]
            step = (g + self.momentum * v) if self.nesterov else v
            p.data -= self.lr * step

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adagrad.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self._s[i] + g * g
            p.data -= self.lr * g / (np.sqrt(self._s[i]) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement RMSprop.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self.alpha * self._s[i] + (1 - self.alpha) * (g * g)
            p.data -= self.lr * g / (np.sqrt(self._s[i]) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adam.step")
+ added
    def step(self):
        self.t += 1
        t = self.t
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** t)
            vhat = self._v[i] / (1 - self.b2 ** t)
            p.data -= self.lr * mhat / (np.sqrt(vhat) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement AdamW.step")
+ added
    def step(self):
        self.t += 1
        t = self.t
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** t)
            vhat = self._v[i] / (1 - self.b2 ** t)
            wd_eff = 0.0 if p.data.ndim <= self.no_decay_ndim else self.weight_decay
            p.data -= self.lr * (mhat / (np.sqrt(vhat) + self.eps) + wd_eff * p.data)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adamax.step")
+ added
    def step(self):
        self.t += 1
        t = self.t
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._u[i] = np.maximum(self.b2 * self._u[i], np.abs(g))
            p.data -= (self.lr / (1 - self.b1 ** t)) * self._m[i] / (self._u[i] + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement NAdam.step")
+ added
    def step(self):
        self.t += 1
        t = self.t
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** t)
            vhat = self._v[i] / (1 - self.b2 ** t)
            mnes = self.b1 * mhat + (1 - self.b1) * g / (1 - self.b1 ** t)
            p.data -= self.lr * mnes / (np.sqrt(vhat) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Lion.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad
            c = np.sign(self.b1 * self._m[i] + (1 - self.b1) * g)
            p.data -= self.lr * (c + self.weight_decay * p.data)
            self._m[i] = self.b2 * self._m[i] + (1 - self.b2) * g

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adadelta.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self.rho * self._s[i] + (1 - self.rho) * (g * g)
            delta = np.sqrt(self._d[i] + self.eps) / np.sqrt(self._s[i] + self.eps) * g
            p.data -= self.lr * delta
            self._d[i] = self.rho * self._d[i] + (1 - self.rho) * (delta * delta)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the clippers and schedulers:

/app/submission/optim.py

− removed
    If total > max_norm, scale
    every grad by max_norm/(total+1e-6)."""
    raise NotImplementedError("implement clip_grad_norm")
+ added
    If total > max_norm, scale
    every grad by max_norm/(total+1e-6)."""
    total_sq = 0.0
    for p in params:
        if p.grad is not None:
            total_sq += float((p.grad ** 2).sum())
    total = math.sqrt(total_sq)
    if total > max_norm:
        scale = max_norm / (total + 1e-6)
        for p in params:
            if p.grad is not None:
                p.grad = p.grad * scale
    return total

contents
<tool_use_error>String to replace not found in file.
String:     If total > max_norm, scale
    every grad by max_norm/(total+1e-6)."""
    raise NotImplementedError("implement clip_grad_norm")</tool_use_error>

/app/submission/optim.py

− removed
    raise NotImplementedError("implement clip_grad_norm")
+ added
    total_sq = 0.0
    for p in params:
        if p.grad is not None:
            total_sq += float((p.grad ** 2).sum())
    total = math.sqrt(total_sq)
    if total > max_norm:
        scale = max_norm / (total + 1e-6)
        for p in params:
            if p.grad is not None:
                p.grad = p.grad * scale
    return total

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement clip_grad_value")
+ added
    for p in params:
        if p.grad is not None:
            p.grad = np.clip(p.grad, -clip_value, clip_value)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement cosine_lr")
+ added
    if warmup > 0 and step < warmup:
        return base_lr * (step + 1) / warmup
    prog = min(1.0, max(0.0, (step - warmup) / max(1, total - warmup)))
    return min_lr + 0.5 * (base_lr - min_lr) * (1 + math.cos(math.pi * prog))

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement warmup_lr")
+ added
    return base_lr * (step + 1) / warmup if step < warmup else base_lr

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement step_lr")
+ added
    return base_lr * gamma ** (step // step_size)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement exponential_lr")
+ added
    return base_lr * gamma ** step

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement polynomial_lr")
+ added
    prog = min(1.0, max(0.0, step / total))
    return (base_lr - min_lr) * ((1.0 - prog) ** power) + min_lr

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement linear_lr")
+ added
    prog = min(1.0, max(0.0, step / total))
    return base_lr + (min_lr - base_lr) * prog

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only optim 2>&1 | tail -35 && python3 run_checks.py --only nn_forward 2>&1 | tail -5
output
[optim]  20/20
  optim/SGD_1step                          OK    (max_abs=0.0e+00)
  optim/SGD_momentum_5step                 OK    (max_abs=0.0e+00)
  optim/SGD_nesterov_5step                 OK    (max_abs=0.0e+00)
  optim/Adagrad_5step                      OK    (max_abs=0.0e+00)
  optim/RMSprop_5step                      OK    (max_abs=0.0e+00)
  optim/Adam_10step_wd                     OK    (max_abs=0.0e+00)
  optim/AdamW_10step_wd                    OK    (max_abs=0.0e+00)
  optim/Adamax_8step                       OK    (max_abs=0.0e+00)
  optim/NAdam_8step                        OK    (max_abs=0.0e+00)
  optim/Lion_8step_wd                      OK    (max_abs=0.0e+00)
  optim/Adadelta_8step                     OK    (max_abs=0.0e+00)
  optim/clip_grad_norm_clips               OK    (max_abs=0.0e+00)
  optim/clip_grad_norm_noop                OK    (max_abs=0.0e+00)
  optim/clip_grad_value                    OK    (max_abs=0.0e+00)
  optim/sched_cosine_lr                    OK    (match)
  optim/sched_warmup_lr                    OK    (match)
  optim/sched_step_lr                      OK    (match)
  optim/sched_exponential_lr               OK    (match)
  optim/sched_polynomial_lr                OK    (match)
  optim/sched_linear_lr                    OK    (match)

------------------------------------------------------------------------
optim 20/20
TOTAL  20/20 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy 
…[truncated 373 chars]
Now data.py:

/app/submission/data.py

− removed
def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
    raise NotImplementedError("implement load_npz")


def train_val_split(X: np.ndarray, y: np.ndarray, val_frac: float,
                    rng: np.random.Generator):
    raise NotImplementedError("implement train_val_split")


def iter_batches(X: np.ndarray, y: np.ndarray, batch_size: int,
                 rng: np.random.Generator) -> Iterator[Tuple[np.ndarray, np.ndarray]]:
    raise NotImplementedError("implement iter_batches")


def get_batch(X: np.ndarray, y: np.ndarray, batch_size: int,
              rng: np.random.Generator) -> Tuple[np.ndarray, np.ndarray]:
    """A single random minibatch (without replacement if possible). Shape-preserving."""
    raise NotImplementedError("implement get_batch")


def to_onehot(y: np.ndarray, n_classes: int) -> np.ndarray:
    """(N, n_classes) one-hot float matrix from integer labels y."""
    raise NotImplementedError("implement to_onehot")


def clip01(X: np.ndarray) -> np.ndarray:
    """Clamp X into the [0,1] pixel domain (the valid attack range)."""
    raise NotImplementedError("implement clip01")
+ added
def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
    d = np.load(path)
    X = np.asarray(d["X"], dtype=np.float64)
    y = np.asarray(d["y"], dtype=np.int64)
    return X, y


def train_val_split(X: np.ndarray, y: np.ndarray, val_frac: float,
                    rng: np.random.Generator):
    N = X.shape[0]
    perm = rng.permutation(N)
    n_val = int(round(val_frac * N))
    val_idx = perm[:n_val]
    tr_idx = perm[n_val:]
    return (X[tr_idx], y[tr_idx]), (X[val_idx], y[val_idx])


def iter_batches(X: np.ndarray, y: np.ndarray, batch_size: int,
                 rng: np.random.Generator) -> Iterator[Tuple[np.ndarray, np.ndarray]]:
    N = X.shape[0]
    perm = rng.permutation(N)
    for s in range(0, N, batch_size):
        idx = perm[s:s + batch_size]
        yield X[idx], y[idx]


def get_batch(X: np.ndarray, y: np.ndarray, batch_size: int,
              rng: np.random.Generator) -> Tuple[np.ndarray, np.ndarray]:
    """A single random minibatch (without replacement if possible). Shape-preserving."""
    N = X.shape[0]
    if batch_size <= N:
        idx = rng.choice(N, size=batch_size, replace=False)
    else:
        idx = rng.choice(N, size=batch_size, replace=True)
    return X[idx], y[idx]


def to_onehot(y: np.ndarray, n_classes: int) -> np.ndarray:
    """(N, n_classes) one-hot float matrix from integer labels y."""
    y = np.asarray(y)
    oh = np.zeros((y.shape[0], n_classes), dtype=np.float64)
    oh[np.arange(y.shape[0]), y] = 1.0
    return oh


de
…[truncated 142 chars]

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now attack.py , I'll write the full implementation:
write · /app/submission/attack.py
"""White-box evasion attacks built on the from-scratch autograd engine."""
from __future__ import annotations

from typing import Callable, Optional, Tuple

import numpy as np

import autograd as ag
from autograd import Tensor


def _default_rng(rng):
    return np.random.default_rng() if rng is None else rng


def loss_input_grad(model, x: np.ndarray, y: np.ndarray,
                    loss_fn: Callable[[Tensor, np.ndarray], Tensor]) -> np.ndarray:
    xt = Tensor(np.asarray(x, dtype=np.float64), requires_grad=True)
    logits = model(xt)
    loss = loss_fn(logits, y)
    loss.backward()
    return np.asarray(xt.grad, dtype=np.float64)


def input_grad(model, x: np.ndarray, y: np.ndarray) -> np.ndarray:
    return loss_input_grad(model, x, y, lambda lg, t: ag.cross_entropy(lg, t))


def _onehot(y, C):
    y = np.asarray(y)
    oh = np.zeros((y.shape[0], C), dtype=np.float64)
    oh[np.arange(y.shape[0]), y] = 1.0
    return oh


def cw_margin_loss(logits, y, kappa: float = 0.0) -> Tensor:
    logits = ag._ensure(logits)
    C = logits.shape[-1]
    oh = _onehot(y, C)
    z_y = ag.sum(ag.mul(logits, Tensor(oh)), axis=1)
    masked = ag.add(logits, Tensor(oh * -1e9))
    other = ag.max(masked, axis=1)
    margin = ag.sub(z_y, other)
    return ag.mean(ag.maximum(ag.mul(margin, -1.0), -kappa))


def dlr_loss(logits, y, eps: float = 1e-12) -> Tensor:
    logits = ag._ensure(logits)
    C = logits.shape[-1]
    oh = _onehot(y, C)
    z_y = ag.sum(ag.mul(logits, Tensor(oh)), axis=
…[truncated 7792 chars]

contents
The file /app/submission/attack.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only attack 2>&1 | tail -25
output
[attack]  18/18
  attack/input_grad_fd                     OK    (max_abs=2.73e-11)
  attack/cw_loss_input_grad_fd             OK    (max_abs=4.13e-12)
  attack/dlr_loss_grad                     OK    (max_abs=1.04e-09)
  attack/dlr_loss_input_grad_fd            OK    (max_abs=3.51e-11)
  attack/fgsm_step                         OK  
  attack/pgd_projection                    OK  
  attack/mi_fgsm_projection                OK  
  attack/cw_pgd_projection                 OK  
  attack/pgd_l2_projection                 OK  
  attack/bim_projection                    OK  
  attack/rfgsm_projection                  OK  
  attack/ni_fgsm_projection                OK  
  attack/pgd_restarts_projection           OK  
  attack/dlr_pgd_projection                OK  
  attack/pgd_stronger_than_fgsm            OK    (fgsm=1.450 pgd=1.469)
  attack/bim_stronger_than_fgsm            OK    (fgsm=1.411 bim=1.423)
  attack/pgd_restarts_worst_case           OK    (single=1.521 restarts=1.524)
  attack/targeted_pgd_lowers_target_ce     OK    (1.388->1.333)

------------------------------------------------------------------------
attack 18/18
TOTAL  18/18 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
Now advtrain.py:

/app/submission/advtrain.py

− removed
def pgd_at_loss(model, x_adv: np.ndarray, y: np.ndarray) -> Tensor:
    """Madry PGD-AT loss: cross-entropy on the adversarial batch (trains parameters)."""
    raise NotImplementedError("implement pgd_at_loss")


def trades_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
                beta: float = 6.0) -> Tuple[Tensor, Dict[str, float]]:
    """TRADES loss = CE(clean, y) + beta * KL(stopgrad(softmax(clean)) || softmax(adv))."""
    raise NotImplementedError("implement trades_loss")


def mart_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
              beta: float = 5.0) -> Tuple[Tensor, Dict[str, float]]:
    """MART loss (boosted CE on adv + misclassification-aware weighted KL with the clean target
    DETACHED); see the module docstring for the exact form."""
    raise NotImplementedError("implement mart_loss")


def alp_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
             lam: float = 0.5) -> Tuple[Tensor, Dict[str, float]]:
    """Adversarial Logit Pairing: 0.5*(CE(clean)+CE(adv)) + lam*mean||z_clean - z_adv||^2 (no detach)."""
    raise NotImplementedError("implement alp_loss")


def label_smoothed_ce(logits, y, eps_ls: float = 0.1, n_classes: int = None) -> Tensor:
    """CE against a label-smoothed target ((1-eps_ls)*onehot + eps_ls/C*uniform), via log_softmax."""
    raise NotImplementedError("implement label_smoothed_ce")


def robust_ce_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.nd
…[truncated 1782 chars]
+ added
def _detach(t: Tensor) -> Tensor:
    return Tensor(t.data.copy())


def _onehot(y, C):
    y = np.asarray(y)
    oh = np.zeros((y.shape[0], C), dtype=np.float64)
    oh[np.arange(y.shape[0]), y] = 1.0
    return oh


def pgd_at_loss(model, x_adv: np.ndarray, y: np.ndarray) -> Tensor:
    """Madry PGD-AT loss: cross-entropy on the adversarial batch (trains parameters)."""
    return ag.cross_entropy(model(x_adv), y)


def trades_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
                beta: float = 6.0) -> Tuple[Tensor, Dict[str, float]]:
    """TRADES loss = CE(clean, y) + beta * KL(stopgrad(softmax(clean)) || softmax(adv))."""
    cl = model(x_clean)
    ad = model(x_adv)
    ce = ag.cross_entropy(cl, y)
    tgt = _detach(cl)
    kl = ag.kl_div(tgt, ad)
    loss = ag.add(ce, ag.mul(kl, float(beta)))
    return loss, {"ce": float(ce.data), "kl": float(kl.data), "loss": float(loss.data)}


def mart_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
              beta: float = 5.0) -> Tuple[Tensor, Dict[str, float]]:
    """MART loss (boosted CE on adv + misclassification-aware weighted KL with the clean target
    DETACHED)."""
    ad = model(x_adv)
    C = ad.shape[-1]
    oh = _onehot(y, C)
    ce_adv = ag.cross_entropy(ad, y)
    p_adv = ag.softmax(ad)
    masked = ag.add(p_adv, Tensor(oh * -1e9))
    m = ag.max(masked, axis=1)                      # max_{j!=y} p_adv_j  (N,)
    boost = ag.mul(ag.mean(ag.log(ag.add(ag.sub(1.0, m), 
…[truncated 4429 chars]

contents
The file /app/submission/advtrain.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only advtrain 2>&1 | tail -20 && python3 run_checks.py --only data 2>&1 | tail -6 && python3 run_checks.py --only integration 2>&1 | tail -8
output
[advtrain]  14/14
  advtrain/at_param_grad                   OK    (max_abs=2.56e-11)
  advtrain/trades_param_grad               OK    (max_abs=5.66e-04)
  advtrain/mart_param_grad                 OK    (max_abs=1.14e-04)
  advtrain/alp_param_grad                  OK    (max_abs=2.60e-11)
  advtrain/robust_ce_param_grad            OK    (max_abs=5.12e-11)
  advtrain/clp_param_grad                  OK    (max_abs=2.84e-05)
  advtrain/kl_at_param_grad                OK    (max_abs=1.62e-03)
  advtrain/logit_squeeze_param_grad        OK    (max_abs=4.80e-11)
  advtrain/ls_at_param_grad                OK    (max_abs=2.14e-11)
  advtrain/label_smoothed_ce_grad          OK  
  advtrain/trades_stopgrad                 OK    (max_abs=0.00e+00)
  advtrain/alp_pairing                     OK    (max_abs=0.00e+00)
  advtrain/clp_stopgrad                    OK    (max_abs=0.00e+00)
  advtrain/kl_at_stopgrad                  OK    (max_abs=0.00e+00)

------------------------------------------------------------------------
advtrain 14/14
TOTAL  14/14 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
  data/to_onehot                           OK  

------------------------------------------------------------------------
data 3/3
TOTAL  3/3 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; t
…[truncated 554 chars]
All public checks pass. Let me confirm the full run and run the smoke test:
shell
python3 run_checks.py 2>&1 | tail -4 && echo "=== SMOKE ===" && cat test.sh
output
------------------------------------------------------------------------
autograd_grads 82/82 | nn_forward 22/22 | optim 20/20 | attack 18/18 | advtrain 14/14 | integration 4/4 | data 3/3
TOTAL  163/163 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
=== SMOKE ===
#!/usr/bin/env bash
# Smoke test (NOT the grader): confirms the environment is wired -- numpy imports, the training
# split loads, and the submission stubs are present. It does NOT check correctness (the stubs raise
# NotImplementedError until you implement them).
set -uo pipefail

python3 - <<'PY'
import numpy as np, os
p = "/app/data/train.npz"
assert os.path.exists(p), "missing train.npz"
d = np.load(p)
print(f"train.npz: X{d['X'].shape} {d['X'].dtype}  y{d['y'].shape}  classes={len(set(d['y'].tolist()))}")
for f in ("autograd.py", "nn.py", "optim.py", "data.py", "attack.py", "advtrain.py", "train.py"):
    assert os.path.exists(f"/app/submission/{f}"), f"missing /app/submission/{f}"
assert os.path.exists("/app/run_checks.py"), "missing /app/run_checks.py (public component runner)"
print("submission stubs present:", sorted(os.listdir("/app/submission")))
print("numpy", np.__version__)
PY
echo "app_test smoke OK (run 'python3 /app/run_checks.py' for the per-check progress report)"
All 163 public checks pass. Now let me implement the training loop:

/app/submission/train.py

− removed
def train(train_path, out_path, epochs=12, batch_size=128, lr=1.2e-3, eps=0.12,
          at_steps=7, alpha=0.03, grad_clip=1.0, weight_decay=5e-4, val_frac=0.15,
          sel_steps=7, seed=0, log_every=1):
    """Run multi-step PGD adversarial training and save the best-by-robust-val checkpoint to
    ``out_path``. See the module docstring for the recipe."""
    raise NotImplementedError("implement the adversarial-training loop")
+ added
def _accuracy(model, X, y, bs=256):
    correct = 0
    for s in range(0, X.shape[0], bs):
        logits = model(X[s:s + bs]).data
        correct += int((logits.argmax(axis=1) == y[s:s + bs]).sum())
    return correct / X.shape[0]


def _robust_accuracy(model, X, y, eps, steps, alpha, restarts, rng, bs=256):
    """Fraction correct cleanly AND surviving every PGD restart (worst-case)."""
    robust = 0
    total = X.shape[0]
    for s in range(0, total, bs):
        xb = X[s:s + bs]
        yb = y[s:s + bs]
        clean_pred = model(xb).data.argmax(axis=1)
        surv = clean_pred == yb
        for _ in range(restarts):
            xa = A.pgd_attack(model, xb, yb, eps, steps, alpha,
                              rng=np.random.default_rng(rng.integers(0, 2 ** 31 - 1)))
            adv_pred = model(xa).data.argmax(axis=1)
            surv = surv & (adv_pred == yb)
        robust += int(surv.sum())
    return robust / total


def train(train_path, out_path, epochs=25, batch_size=128, lr=1.2e-3, eps=0.12,
          at_steps=10, alpha=0.031, grad_clip=1.0, weight_decay=5e-4, val_frac=0.12,
          sel_steps=20, seed=0, log_every=1):
    """Run multi-step PGD adversarial training and save the best-by-robust-val checkpoint."""
    rng = np.random.default_rng(seed)
    X, y = D.load_npz(train_path)
    n_classes = int(y.max()) + 1
    c_in = X.shape[1]
    img = X.shape[2]
    (Xtr, ytr), (Xval, yval) = D.train_val_split(X, y, val_frac, rng)

    model = SmallCNN(n_classes=n_cl
…[truncated 1752 chars]

contents
The file /app/submission/train.py has been updated successfully. (file state is current in your context , no need to Read it back)
Let me first time a quick 2-epoch run to gauge speed:
shell
cd /app/submission && time python3 -c "
import train
sd, rob = train.train('/app/data/train.npz', '/tmp/test_model.npz', epochs=2, at_steps=7, sel_steps=10)
" 2>&1 | tail -10
output
real	0m5.632s
user	0m1.753s
sys	0m1.350s
shell
python3 -c "
import train
sd, rob = train.train('/app/data/train.npz', '/tmp/test_model.npz', epochs=2, at_steps=7, sel_steps=10)
" 2>&1
output
Exit code 137
/bin/bash: line 7:  1584 Killed                  python3 -c "
import train
sd, rob = train.train('/app/data/train.npz', '/tmp/test_model.npz', epochs=2, at_steps=7, sel_steps=10)
" 2>&1
shell
python3 -c "
import numpy as np, resource, data as D, attack as A, advtrain as AT, optim as O
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
xb,yb=X[:128],y[:128]
xa=A.pgd_attack(m,xb,yb,0.12,7,0.031,rng=np.random.default_rng(0))
print('pgd ok', xa.shape)
loss=AT.pgd_at_loss(m,xa,yb); 
o=O.AdamW(m.params()); o.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),1.0); o.step()
print('step ok loss', float(loss.data))
print('peak MB', resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024)
" 2>&1 | tail
output
pgd ok (128, 1, 16, 16)
step ok loss 1.8639379739369182
peak MB 202.30078125
shell
python3 -c "
import numpy as np, resource, gc, data as D, attack as A, advtrain as AT, optim as O
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
o=O.AdamW(m.params(),lr=1e-3)
rng=np.random.default_rng(0)
import time; t=time.time()
for i in range(50):
    idx=rng.integers(0,X.shape[0],128); xb,yb=X[idx],y[idx]
    xa=A.pgd_attack(m,xb,yb,0.12,10,0.031,rng=rng)
    loss=AT.pgd_at_loss(m,xa,yb); o.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),1.0); o.step()
    if i%10==0: print(i,'MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024),'t',round(time.time()-t,1),flush=True)
print('done MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024))
" 2>&1 | tail
output
(Bash completed with no output)
shell
python3 -u -c "
import numpy as np, resource, data as D, attack as A, advtrain as AT, optim as O
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
o=O.AdamW(m.params(),lr=1e-3)
rng=np.random.default_rng(0)
for i in range(50):
    idx=rng.integers(0,X.shape[0],128); xb,yb=X[idx],y[idx]
    xa=A.pgd_attack(m,xb,yb,0.12,10,0.031,rng=rng)
    loss=AT.pgd_at_loss(m,xa,yb); o.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),1.0); o.step()
    print(i,'MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024),flush=True)
"; echo "EXIT $?"
output
/bin/bash: line 25:  1599 Killed                  python3 -u -c "
import numpy as np, resource, data as D, attack as A, advtrain as AT, optim as O
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
o=O.AdamW(m.params(),lr=1e-3)
rng=np.random.default_rng(0)
for i in range(50):
    idx=rng.integers(0,X.shape[0],128); xb,yb=X[idx],y[idx]
    xa=A.pgd_attack(m,xb,yb,0.12,10,0.031,rng=rng)
    loss=AT.pgd_at_loss(m,xa,yb); o.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),1.0); o.step()
    print(i,'MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024),flush=True)
"
EXIT 137
shell
python3 -u -c "
import numpy as np, resource, data as D, attack as A, advtrain as AT, optim as O
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
o=O.AdamW(m.params(),lr=1e-3)
rng=np.random.default_rng(0)
idx=rng.integers(0,X.shape[0],128); xb,yb=X[idx],y[idx]
print('start',flush=True)
xa=A.pgd_attack(m,xb,yb,0.12,10,0.031,rng=rng)
print('after pgd MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024),flush=True)
"; echo "EXIT $?"
output
start
/bin/bash: line 23:  1605 Killed                  python3 -u -c "
import numpy as np, resource, data as D, attack as A, advtrain as AT, optim as O
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
o=O.AdamW(m.params(),lr=1e-3)
rng=np.random.default_rng(0)
idx=rng.integers(0,X.shape[0],128); xb,yb=X[idx],y[idx]
print('start',flush=True)
xa=A.pgd_attack(m,xb,yb,0.12,10,0.031,rng=rng)
print('after pgd MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024),flush=True)
"
EXIT 137
A single 10-step PGD is OOM-killed , the autograd closures form reference cycles (each `out._backward` captures `out`), so graphs aren't freed by refcounting. Let me test whether explicit GC fixes it:
shell
python3 -u -c "
import numpy as np, resource, gc, data as D, attack as A
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
rng=np.random.default_rng(0)
idx=rng.integers(0,X.shape[0],128); xb,yb=X[idx],y[idx]
for s in range(10):
    g=A.input_grad(m,xb,yb); gc.collect()
    print(s,'MB',round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024),flush=True)
"; echo EXIT $?
output
0 MB 82
1 MB 83
2 MB 85
3 MB 85
4 MB 85
5 MB 85
6 MB 85
7 MB 85
8 MB 85
9 MB 85
EXIT 0
gc keeps it flat but is slow per-call. The clean fix is to break the cycle: make backward closures take the gradient as a parameter instead of capturing `out`. Let me refactor with sed:
shell
python3 - <<'PY'
import re
s=open('autograd.py').read()
# closures: take g param
s=s.replace('def bw():','def bw(g):')
s=s.replace('def bw_id():','def bw_id(g):')
# replace out.grad usages inside closures with g
s=s.replace('out.grad','g')
# default backward + dispatch
s=s.replace('self._backward: Callable[[], None] = lambda: None','self._backward: Callable = lambda g: None')
s=s.replace('            t._backward()','            t._backward(t.grad)')
open('autograd.py','w').write(s)
print('done; remaining out.data refs:')
import subprocess
print(subprocess.run(['grep','-n','out.data', 'autograd.py'],capture_output=True,text=True).stdout)
print('g = g lines:', s.count('g = g'))
PY
output
done; remaining out.data refs:
298:            a._accum(g * out.data)
320:            a._accum(g * 0.5 / out.data)

g = g lines: 17
Now fix the two `out.data` references in exp/sqrt closures to avoid capturing `out`:

/app/submission/autograd.py

− removed
def exp(a) -> Tensor:
    a = _ensure(a)
    out = Tensor(np.exp(a.data), requires_grad=_rg(a), _parents=(a,))

    def bw(g):
        if a.requires_grad:
            a._accum(g * out.data)
    out._backward = bw
    return out
+ added
def exp(a) -> Tensor:
    a = _ensure(a)
    e = np.exp(a.data)
    out = Tensor(e, requires_grad=_rg(a), _parents=(a,))

    def bw(g):
        if a.requires_grad:
            a._accum(g * e)
    out._backward = bw
    return out

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
def sqrt(a) -> Tensor:
    a = _ensure(a)
    out = Tensor(np.sqrt(a.data), requires_grad=_rg(a), _parents=(a,))

    def bw(g):
        if a.requires_grad:
            a._accum(g * 0.5 / out.data)
    out._backward = bw
    return out
+ added
def sqrt(a) -> Tensor:
    a = _ensure(a)
    r = np.sqrt(a.data)
    out = Tensor(r, requires_grad=_rg(a), _parents=(a,))

    def bw(g):
        if a.requires_grad:
            a._accum(g * 0.5 / r)
    out._backward = bw
    return out

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now let me verify no closures still reference `out` and re-run the checks plus the memory test:
shell
cd /app && grep -n "out.grad\|out.data" submission/autograd.py; echo "---grep done---"; python3 run_checks.py 2>&1 | tail -3
output
---grep done---
autograd_grads 77/82 | nn_forward 22/22 | optim 20/20 | attack 18/18 | advtrain 14/14 | integration 4/4 | data 3/3
TOTAL  158/163 public checks passing
Fix the FAIL lines above, then re-run. Each names a backward/forward/optimizer/attack/adversarial-training bug.
shell
python3 run_checks.py --only autograd_grads 2>&1 | grep FAIL
output
grad/getitem_row                         FAIL  (raised ValueError: array is not broadcastable to correct shape)
  grad/getitem_slice                       FAIL  (raised ValueError: array is not broadcastable to correct shape)
  grad/embedding                           FAIL  (raised ValueError: array is not broadcastable to correct shape)
  grad/grucell                             FAIL  (raised ValueError: array is not broadcastable to correct shape)
  grad/lstmcell                            FAIL  (raised ValueError: array is not broadcastable to correct shape)
Fix the FAIL lines above, then re-run. Each names a backward/forward/optimizer/attack/adversarial-training bug.
The sed caused a name collision in `getitem`/`embedding` where a local zeros array was also named `g`. Let me fix:

/app/submission/autograd.py

− removed
    out = Tensor(a.data[idx], requires_grad=_rg(a), _parents=(a,))

    def bw(g):
        if a.requires_grad:
            g = np.zeros_like(a.data)
            np.add.at(g, idx, g)
            a._accum(g)
    out._backward = bw
    return out
+ added
    out = Tensor(a.data[idx], requires_grad=_rg(a), _parents=(a,))

    def bw(g):
        if a.requires_grad:
            ga = np.zeros_like(a.data)
            np.add.at(ga, idx, g)
            a._accum(ga)
    out._backward = bw
    return out

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
API Error: Server is temporarily limiting requests (not your usage limit) · Rate limited
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 verifier (local re-grade of the agent's own checkpoint) ===

COMPONENT CONFORMANCE SUITE: 200/201 cases passed  (all milestones pass: False)
  failing milestones: autograd_grads (86/87)
FINAL METRIC: PGD robust accuracy = 0.58  < threshold 0.6

REWARD = 0   (1 iff every component milestone passes AND the sealed held-out metric clears its threshold)

NOTE: the in-sandbox training in the 481MB e2b box was OOM-killed (0-byte checkpoint), so the raw
in-sandbox reward was an infrastructure artifact. This reward is from a faithful LOCAL re-train of the
agent's OWN train.py (24GB, no OOM) with its own default hyperparameters, then re-graded by the real verifier.

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_5c08b25117294d2b. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_5c08b25117294d2b · verifier authoritative; classifier explanatory.