Agent Conversation: deepseek-reasoner
Task: cv-classification-loss
CV Classification Loss Function Design
Research Question
Design a novel classification loss function for deep convolutional neural networks that improves test accuracy across different architectures and datasets.
Background
The cross-entropy loss is the standard training objective for classification networks, but it has known limitations: it treats all misclassifications equally, assigns high confidence to correct predictions without margin, and does not adapt to training dynamics. Researchers have proposed alternatives:
- Label Smoothing (Szegedy et al., 2016): Softens hard targets to prevent overconfidence, CE with targets = (1-eps)*one_hot + eps/C
- Focal Loss (Lin et al., ICCV 2017): Down-weights easy examples via (1-pt)^gamma modulation
- PolyLoss (Leng et al., ICLR 2022): Extends CE with polynomial correction terms, CE + eps*(1-pt)
However, these methods are either static or address only specific failure modes. There is room to design loss functions that combine multiple insights: confidence calibration, curriculum-style epoch adaptation, class-count awareness, or learned temperature scaling.
What You Can Modify
The compute_loss(logits, targets, config) function (lines 165-185) in custom_loss.py. This function receives raw logits, integer targets, and a config dict, and must return a differentiable scalar loss.
You can modify:
- The loss formulation (cross-entropy variants, margin losses, etc.)
- Confidence-based reweighting schemes
- Epoch-dependent curriculum strategies using
config['epoch']andconfig['total_epochs'] - Class-count-dependent behavior using
config['num_classes'] - Temperature or logit scaling
- Auxiliary regularization terms (entropy, logit penalties, etc.)
The config dict provides: num_classes (int), epoch (int, 0-indexed), total_epochs (int).
Important: The evaluation loss (for test_loss reporting) always uses standard cross-entropy. Your loss function only affects training.
Evaluation
- Metric: Best test accuracy (%, higher is better)
- Architectures & datasets:
- ResNet-56 on CIFAR-100 (deep residual, 100 classes)
- VGG-16-BN on CIFAR-100 (deep non-residual with BatchNorm, 100 classes)
- MobileNetV2 on FashionMNIST (lightweight inverted-residual, 10 classes) — hidden, evaluated on final submission only
- Training: SGD (lr=0.1, momentum=0.9, wd=5e-4), cosine annealing, 200 epochs
- Data augmentation: RandomCrop(32, pad=4) + RandomHorizontalFlip
pytorch-vision/custom_loss.py [EDITABLE — lines 246–266 only]
1: """CV Classification Loss Benchmark.
2:
3: Train vision models (ResNet, VGG, MobileNetV2) on CIFAR-10/100/FashionMNIST to evaluate
4: classification loss function designs.
5:
6: FIXED: Model architectures, weight initialization, data pipeline, training loop.
7: EDITABLE: compute_loss() function.
8:
9: Usage:
10: python custom_loss.pyTool Input
1{
2 "op": "replace",
3 "filename": "pytorch-vision/custom_loss.py",
4 "start_line": 246,
5 "end_line": 266,
6 "content": "def compute_loss(logits, targets, config):\n \"\"\"Adaptive Curriculum Margin Loss (ACML).\n\n Combines:\n 1. Curriculum margin that increases with epoch progression.\n 2. Focal weighting for hard examples.\n 3. Label smoothing for calibration.\n 4. Adaptive temperature scaling.\n\n Hyperparameters:\n base_margin: maximum margin at final epoch\n gamma: controls margin progression rate\n beta: focal weighting strength\n tau: temperature scaling magnitude\n smoothing_eps: label smoothing factor\n \"\"\"\n # Hyperparameters (hardcoded)\n base_margin = 0.5\n gamma = 2.0\n beta = 2.0\n tau = 1.0\n smoothing_eps = 0.1\n\n num_classes = config['num_classes']\n epoch = config['epoch']\n total_epochs = config['total_epochs']\n\n B = logits.size(0)\n\n # Curriculum progression factor (0 to 1)\n progress = epoch / max(total_epochs - 1, 1) # avoid division by zero\n\n # Dynamic margin that increases with progress\n margin = base_margin * (progress ** gamma)\n\n # Adaptive temperature: starts warm (higher temp), ends cool (lower temp)\n temperature = 1.0 + tau * (1.0 - progress) # temperature decreases as progress increases\n\n # Apply margin to logits: subtract margin from true class logit\n logits_adjusted = logits.clone()\n logits_adjusted[range(B), targets] -= margin\n\n # Apply temperature scaling\n logits_adjusted = logits_adjusted / temperature\n\n # Compute softmax probabilities\n probs = F.softmax(logits_adjusted, dim=-1)\n pt = probs[range(B), targets] # probability of true class\n\n # Focal weighting: down-weight easy examples\n focal_weight = (1.0 - pt) ** beta\n\n # Label smoothing target distribution\n one_hot = F.one_hot(targets, num_classes).float()\n smoothed_targets = (1.0 - smoothing_eps) * one_hot + smoothing_eps / num_classes\n\n # Compute cross-entropy between smoothed targets and adjusted logits\n log_probs = F.log_softmax(logits_adjusted, dim=-1)\n ce = -(smoothed_targets * log_probs).sum(dim=-1) # [B]\n\n # Weighted loss\n loss = (focal_weight * ce).mean()\n\n return loss"
7}OK: Replaced lines 246..266 with 64 line(s) in pytorch-vision/custom_loss.py. Editable range: 246–309. [Current file: pytorch-vision/custom_loss.py | editable: 246–309 | total: 479 lines] 243| # ============================================================================ 244| 245| # -- EDITABLE REGION START (lines 246-266) ------------------------------------ 246 def compute_loss(logits, targets, config): 247 """Adaptive Curriculum Margin Loss (ACML). 248 249 Combines: 250 1. Curriculum margin that increases with epoch progression. 251 2. Focal weighting for hard examples. 252 3. Label smoothing for calibration. 253 4. Adaptive temperature scaling. 254 255 Hyperparameters: 256 base_margin: maximum margin at final epoch 257 gamma: controls margin progression rate 258 beta: focal weighting strength 259 tau: temperature scaling magnitude 260 smoothin
[Test #1] (2 tests remaining; call submit(n=N) to choose which test result to submit as final) ### resnet56-cifar100 (scripts/resnet56_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=0.3967 train_acc=87.46 test_loss=1.3638 test_acc=67.49 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=0.2423 train_acc=92.55 test_loss=1.2600 test_acc=69.82 lr=0.005450 TRAIN_METRICS: epoch=180 train_loss=0.1203 train_acc=96.70 test_loss=1.1875 test_acc=72.03 lr=0.002447 TRAIN_METRICS: epoch=190 train_loss=0.0667 train_acc=98.40 test_loss=1.1575 test_acc=72.46 lr=0.000616 TRAIN_METRICS: epoch=200 train_loss=0.0538 train_acc=98.86 test_loss=1.1574 test_acc=72.65 lr=0.000000 Final metrics (resnet56-cifar100): test_acc_resnet56-cifar100=72.66 ### vgg16bn-cifar100 (scripts/vgg16bn_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=0.1947 train_acc=93.73 test_loss=1.4635 test_acc=68.79 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=0.0744 trai
Tool Input
1{
2 "op": "replace",
3 "filename": "pytorch-vision/custom_loss.py",
4 "start_line": 246,
5 "end_line": 309,
6 "content": "def compute_loss(logits, targets, config):\n \"\"\"Adaptive Margin Focal Loss (AMFL).\n\n Combines:\n 1. Sample-dependent margin: harder examples get larger margin.\n 2. Curriculum progression: margin magnitude increases over epochs.\n 3. Focal weighting for hard examples.\n 4. Label smoothing for calibration.\n 5. Adaptive temperature scaling.\n\n Hyperparameters:\n base_margin: maximum margin at final epoch for easy samples\n gamma: controls margin progression rate over epochs\n alpha: controls margin scaling with sample hardness\n beta: focal weighting strength\n tau: temperature scaling magnitude\n smoothing_eps: label smoothing factor\n \"\"\"\n # Hyperparameters (hardcoded)\n base_margin = 0.3\n gamma = 1.0\n alpha = 1.0\n beta = 2.0\n tau = 0.5\n smoothing_eps = 0.1\n\n num_classes = config['num_classes']\n epoch = config['epoch']\n total_epochs = config['total_epochs']\n\n B = logits.size(0)\n\n # Curriculum progression factor (0 to 1)\n progress = epoch / max(total_epochs - 1, 1) # avoid division by zero\n\n # Adaptive temperature: starts warm (higher temp), ends cool (lower temp)\n temperature = 1.0 + tau * (1.0 - progress) # temperature decreases as progress increases\n\n # Apply temperature scaling to raw logits\n logits_scaled = logits / temperature\n\n # Compute raw probabilities (before margin)\n probs_raw = F.softmax(logits_scaled, dim=-1)\n pt_raw = probs_raw[range(B), targets] # probability of true class before margin\n\n # Sample-dependent margin: larger margin for harder examples\n hardness = 1.0 - pt_raw # hardness ∈ [0,1]\n margin = base_margin * (progress ** gamma) * (hardness ** alpha) # [B]\n\n # Apply margin to logits: subtract margin from true class logit\n logits_adjusted = logits_scaled.clone()\n logits_adjusted[range(B), targets] -= margin\n\n # Compute probabilities after margin\n probs = F.softmax(logits_adjusted, dim=-1)\n pt = probs[range(B), targets] # probability of true class after margin\n\n # Focal weighting: down-weight easy examples\n focal_weight = (1.0 - pt) ** beta\n\n # Label smoothing target distribution\n one_hot = F.one_hot(targets, num_classes).float()\n smoothed_targets = (1.0 - smoothing_eps) * one_hot + smoothing_eps / num_classes\n\n # Compute cross-entropy between smoothed targets and adjusted logits\n log_probs = F.log_softmax(logits_adjusted, dim=-1)\n ce = -(smoothed_targets * log_probs).sum(dim=-1) # [B]\n\n # Weighted loss\n loss = (focal_weight * ce).mean()\n\n return loss"
7}OK: Replaced lines 246..309 with 72 line(s) in pytorch-vision/custom_loss.py. Editable range: 246–317. [Current file: pytorch-vision/custom_loss.py | editable: 246–317 | total: 487 lines] 243| # ============================================================================ 244| 245| # -- EDITABLE REGION START (lines 246-266) ------------------------------------ 246 def compute_loss(logits, targets, config): 247 """Adaptive Margin Focal Loss (AMFL). 248 249 Combines: 250 1. Sample-dependent margin: harder examples get larger margin. 251 2. Curriculum progression: margin magnitude increases over epochs. 252 3. Focal weighting for hard examples. 253 4. Label smoothing for calibration. 254 5. Adaptive temperature scaling. 255 256 Hyperparameters: 257 base_margin: maximum margin at final epoch for easy samples 258 gamma: controls margin progression rate over epochs 259
[Test #2] (1 test remaining; call submit(n=N) to choose which test result to submit as final) ### resnet56-cifar100 (scripts/resnet56_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=0.3599 train_acc=87.82 test_loss=1.2561 test_acc=67.41 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=0.2090 train_acc=92.86 test_loss=1.1764 test_acc=69.78 lr=0.005450 TRAIN_METRICS: epoch=180 train_loss=0.1022 train_acc=96.72 test_loss=1.1170 test_acc=72.03 lr=0.002447 TRAIN_METRICS: epoch=190 train_loss=0.0554 train_acc=98.44 test_loss=1.0999 test_acc=72.36 lr=0.000616 TRAIN_METRICS: epoch=200 train_loss=0.0443 train_acc=98.85 test_loss=1.0977 test_acc=72.51 lr=0.000000 Final metrics (resnet56-cifar100): test_acc_resnet56-cifar100=72.62 ### vgg16bn-cifar100 (scripts/vgg16bn_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=0.1845 train_acc=93.67 test_loss=1.4075 test_acc=67.99 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=0.0667 train
Tool Input
1{
2 "op": "replace",
3 "filename": "pytorch-vision/custom_loss.py",
4 "start_line": 246,
5 "end_line": 317,
6 "content": "def compute_loss(logits, targets, config):\n \"\"\"Curriculum PolyLoss with Adaptive Smoothing.\n\n Combines:\n 1. Label smoothing (fixed epsilon).\n 2. Poly loss term with curriculum: epsilon decreases over epochs.\n 3. Adaptive temperature scaling.\n\n Loss = CE_smoothed + epsilon * (1 - pt)\n where epsilon = base_epsilon * (1 - progress)^gamma\n and temperature = 1 + tau * (1 - progress)\n\n Hyperparameters:\n smoothing_eps: label smoothing factor\n base_epsilon: maximum poly weight at start\n gamma: controls decay rate of poly weight\n tau: temperature scaling magnitude\n \"\"\"\n # Hyperparameters (hardcoded)\n smoothing_eps = 0.1\n base_epsilon = 2.0\n gamma = 0.5\n tau = 0.5\n\n num_classes = config['num_classes']\n epoch = config['epoch']\n total_epochs = config['total_epochs']\n\n # Curriculum progression factor (0 to 1)\n progress = epoch / max(total_epochs - 1, 1) # avoid division by zero\n\n # Adaptive temperature: starts warm (higher temp), ends cool (lower temp)\n temperature = 1.0 + tau * (1.0 - progress) # temperature decreases as progress increases\n\n # Apply temperature scaling\n logits_scaled = logits / temperature\n\n # Compute probabilities\n probs = F.softmax(logits_scaled, dim=-1)\n pt = probs[range(len(targets)), targets] # probability of true class\n\n # Label smoothing target distribution\n one_hot = F.one_hot(targets, num_classes).float()\n smoothed_targets = (1.0 - smoothing_eps) * one_hot + smoothing_eps / num_classes\n\n # Cross-entropy with smoothed targets\n log_probs = F.log_softmax(logits_scaled, dim=-1)\n ce = -(smoothed_targets * log_probs).sum(dim=-1) # [B]\n\n # Curriculum poly weight\n epsilon = base_epsilon * ((1.0 - progress) ** gamma)\n poly_term = epsilon * (1.0 - pt)\n\n # Total loss\n loss = (ce + poly_term).mean()\n\n return loss"
7}OK: Replaced lines 246..317 with 57 line(s) in pytorch-vision/custom_loss.py. Editable range: 246–302. [Current file: pytorch-vision/custom_loss.py | editable: 246–302 | total: 472 lines] 243| # ============================================================================ 244| 245| # -- EDITABLE REGION START (lines 246-266) ------------------------------------ 246 def compute_loss(logits, targets, config): 247 """Curriculum PolyLoss with Adaptive Smoothing. 248 249 Combines: 250 1. Label smoothing (fixed epsilon). 251 2. Poly loss term with curriculum: epsilon decreases over epochs. 252 3. Adaptive temperature scaling. 253 254 Loss = CE_smoothed + epsilon * (1 - pt) 255 where epsilon = base_epsilon * (1 - progress)^gamma 256 and temperature = 1 + tau * (1 - progress) 257 258 Hyperparameters: 259 smoothing_eps: label smoothing factor 260 base_epsilon: maximum poly
[Test #3] (0 tests remaining; call submit(n=N) to choose which test result to submit as final) [NOTE] This was your last test. You MUST now call submit(n=X) to choose which test result to submit as your final answer. ### resnet56-cifar100 (scripts/resnet56_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=1.4335 train_acc=88.03 test_loss=1.3021 test_acc=68.31 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=1.2331 train_acc=92.62 test_loss=1.2605 test_acc=69.79 lr=0.005450 TRAIN_METRICS: epoch=180 train_loss=1.0710 train_acc=96.41 test_loss=1.1836 test_acc=72.39 lr=0.002447 TRAIN_METRICS: epoch=190 train_loss=0.9820 train_acc=98.11 test_loss=1.1619 test_acc=73.26 lr=0.000616 TRAIN_METRICS: epoch=200 train_loss=0.9132 train_acc=98.43 test_loss=1.1748 test_acc=73.07 lr=0.000000 Final metrics (resnet56-cifar100): test_acc_resnet56-cifar100=73.33 ### vgg16bn-cifar100 (scripts/vgg16bn_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 tr
Tool Input
1{
2 "n": 1
3}[submit] Submitting result from test #1 as final. ### resnet56-cifar100 (scripts/resnet56_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=0.3967 train_acc=87.46 test_loss=1.3638 test_acc=67.49 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=0.2423 train_acc=92.55 test_loss=1.2600 test_acc=69.82 lr=0.005450 TRAIN_METRICS: epoch=180 train_loss=0.1203 train_acc=96.70 test_loss=1.1875 test_acc=72.03 lr=0.002447 TRAIN_METRICS: epoch=190 train_loss=0.0667 train_acc=98.40 test_loss=1.1575 test_acc=72.46 lr=0.000616 TRAIN_METRICS: epoch=200 train_loss=0.0538 train_acc=98.86 test_loss=1.1574 test_acc=72.65 lr=0.000000 Final metrics (resnet56-cifar100): test_acc_resnet56-cifar100=72.66 ### vgg16bn-cifar100 (scripts/vgg16bn_cifar100.sh) Training progress (last epochs): TRAIN_METRICS: epoch=160 train_loss=0.1947 train_acc=93.73 test_loss=1.4635 test_acc=68.79 lr=0.009549 TRAIN_METRICS: epoch=170 train_loss=0.0744 train_acc=97.57 test_loss=1.3883 test_acc=72.03 l