Spaces:
Sleeping
Sleeping
File size: 54,655 Bytes
78f28d5 c7acc8d 78f28d5 c7acc8d 78f28d5 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 |
import os
import torch
import torch.nn as nn
import numpy as np
import pandas as pd
from typing import Dict, List, Tuple, Optional
from tqdm import tqdm
from collections import Counter
from sklearn.metrics import confusion_matrix, roc_auc_score, average_precision_score
import warnings
from model import negative_sampling_phla
warnings.filterwarnings("ignore")
from physicochemical import PhysicochemicalEncoder
from model import (
ESM2Encoder,
ESMFoldEncoder,
PeptideHLABindingPredictor,
PepHLA_Dataset,
peptide_hla_collate_fn,
TCRPeptideHLABindingPredictor,
TCRPepHLA_Dataset,
tcr_pep_hla_collate_fn,
EarlyStopping
)
# ============================================================================
# Utility functions
# ============================================================================
def load_train_data(
df_train_list: List[pd.DataFrame],
df_val_list: List[pd.DataFrame],
hla_dict_path: str = 'pMHC/HLA_dict.npy',
) -> Tuple[pd.DataFrame, pd.DataFrame]:
"""
Load training and validation datasets only.
Args:
hla_dict_path: Path to HLA dictionary
train_folds: List of training fold indices
val_folds: List of validation fold indices
sample_frac: Fraction of data to sample (for quick testing)
seed: Random seed
Returns:
df_train, df_val
"""
print("Loading training and validation data...")
# Load HLA dictionary
HLA_dict = np.load(hla_dict_path, allow_pickle=True).item()
# Process HLA names → full sequence
for df in df_train_list + df_val_list:
df['HLA'] = df['HLA'].apply(lambda x: x[4:] if x.startswith('HLA-') else x)
df['HLA_full'] = df['HLA'].apply(lambda x: HLA_dict[x])
return df_train_list, df_val_list
def load_test_data(
df_test: pd.DataFrame,
hla_dict_path: str = 'pMHC/HLA_dict.npy'
) -> pd.DataFrame:
"""
Preprocess a given test DataFrame (e.g. independent or external set).
Args:
df_test: Test dataframe with at least 'HLA', 'peptide', 'label'
hla_dict_path: Path to HLA dictionary (to map HLA name to full sequence)
Returns:
Processed df_test with 'HLA_full' added
"""
print("Processing test data...")
HLA_dict = np.load(hla_dict_path, allow_pickle=True).item()
df_test = df_test.copy()
df_test['HLA'] = df_test['HLA'].apply(lambda x: x[4:] if x.startswith('HLA-') else x)
df_test['HLA_full'] = df_test['HLA'].apply(lambda x: HLA_dict[x])
print(f"✓ Test set: {len(df_test)} samples")
return df_test
class StriMap_pHLA:
"""
StriMap for Structure-informed Peptide-HLA Binding Prediction Model
"""
def __init__(
self,
device: str = 'cuda:0',
model_save_path: str = '/data/model_params/best_model_phla.pt',
pep_dim: int = 256,
hla_dim: int = 256,
bilinear_dim: int = 256,
loss_fn: str = 'bce',
alpha: float = 0.5,
gamma: float = 2.0,
esm2_layer: int = 33,
batch_size: int = 256,
esmfold_cache_dir: str = "/data/esm_cache",
cache_dir: str = '/data/phla_cache',
cache_save: bool = False,
seed: int = 1,
pos_weights: Optional[float] = None
):
"""
Initialize StriMap model
Args:
device: Device for computation
cache_dir: Directory for caching embeddings
model_save_path: Path to save best model
pep_dim: Peptide embedding dimension
hla_dim: HLA embedding dimension
bilinear_dim: Bilinear attention dimension
loss_fn: Loss function ('bce' or 'focal')
alpha: Alpha parameter for focal loss
gamma: Gamma parameter for focal loss
esm2_layer: ESM2 layer to extract features from
esmfold_cache_dir: Cache directory for ESMFold
cache_dir: Directory for caching embeddings
seed: Random seed
"""
self.device = torch.device(device if torch.cuda.is_available() else 'cpu')
self.model_save_path = model_save_path
if not os.path.exists(os.path.dirname(model_save_path)) and os.path.dirname(model_save_path) != '':
os.makedirs(os.path.dirname(model_save_path), exist_ok=True)
self.seed = seed
self.cache_save = cache_save
self.batch_size = batch_size
self.loss_fn_name = loss_fn
self.alpha = alpha
self.gamma = gamma
self.pos_weights = pos_weights
# Set random seeds
self._set_seed(seed)
# Initialize encoders
print("Initializing encoders...")
self.phys_encoder = PhysicochemicalEncoder(device=self.device)
self.esm2_encoder = ESM2Encoder(device=str(self.device), layer=esm2_layer, cache_dir=cache_dir)
self.esmfold_encoder = ESMFoldEncoder(esm_cache_dir=esmfold_cache_dir, cache_dir=cache_dir)
# Initialize model
print("Initializing binding prediction model...")
self.model = PeptideHLABindingPredictor(
pep_dim=pep_dim,
hla_dim=hla_dim,
bilinear_dim=bilinear_dim,
loss_fn=self.loss_fn_name,
alpha=self.alpha,
gamma=self.gamma,
device=str(self.device),
pos_weights=self.pos_weights
).to(self.device)
# Embeddings cache
self.phys_dict = None
self.esm2_dict = None
self.struct_dict = None
print(f"✓ StriMap initialized on {self.device}")
def _set_seed(self, seed: int):
"""Set random seeds for reproducibility"""
np.random.seed(seed)
torch.manual_seed(seed)
torch.cuda.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
torch.backends.cudnn.benchmark = False
torch.backends.cudnn.deterministic = True
def prepare_embeddings(
self,
df: pd.DataFrame,
force_recompute: bool = False,
):
"""
Prepare all embeddings (physicochemical, ESM2, structure)
Args:
df: DataFrame containing 'peptide' and 'HLA_full' columns
force_recompute: Force recomputation even if cache exists
incremental: If True, only compute missing sequences
phys_cache: Physicochemical embeddings cache file
esm2_cache: ESM2 embeddings cache file
struct_cache: Structure embeddings cache file
"""
# Extract unique sequences
all_peptides = sorted(set(df['peptide'].astype(str)))
all_hlas = sorted(set(df['HLA_full'].astype(str)))
print(f"\n{'='*70}")
print(f"Preparing embeddings for:")
print(f" - {len(all_peptides)} unique peptides")
print(f" - {len(all_hlas)} unique HLAs")
print(f"{'='*70}\n")
# ========================================================================
# 1. Physicochemical features
# ========================================================================
self.phys_dict = {
'pep': self._encode_phys(all_peptides),
'hla': self._encode_phys(all_hlas)
}
# ========================================================================
# 2. ESM2 embeddings
# ========================================================================
self.esm2_dict = {
'pep': self._encode_esm2(all_peptides, prefix='pep', re_embed=force_recompute),
'hla': self._encode_esm2(all_hlas, prefix='hla', re_embed=force_recompute)
}
# ========================================================================
# 3. Structure features (only for HLA)
# ========================================================================
self.struct_dict = self._encode_structure(all_hlas)
# ========================================================================
# Summary
# ========================================================================
print(f"{'='*70}")
print("✓ All embeddings prepared!")
print(f" - Phys: {len(self.phys_dict['pep'])} peptides, {len(self.phys_dict['hla'])} HLAs")
print(f" - ESM2: {len(self.esm2_dict['pep'])} peptides, {len(self.esm2_dict['hla'])} HLAs")
print(f" - Struct: {len(self.struct_dict)} HLAs")
print(f"{'='*70}\n")
def _encode_phys(self,
sequences: List[str]) -> Dict[str, torch.Tensor]:
"""Encode physicochemical properties"""
emb_dict = {}
for i in tqdm(range(0, len(sequences), self.batch_size), desc="Phys encoding"):
batch = sequences[i:i+self.batch_size]
embs = self.phys_encoder(batch).cpu() # [B, L, D]
for seq, emb in zip(batch, embs):
emb_dict[seq] = emb
return emb_dict
def _encode_esm2(self, sequences: List[str], prefix: str, re_embed: bool = False) -> Dict[str, torch.Tensor]:
"""Encode with ESM2"""
df_tmp = pd.DataFrame({'seq': sequences})
emb_dict = self.esm2_encoder.forward(
df_tmp,
seq_col='seq',
prefix=prefix,
batch_size=self.batch_size,
re_embed=re_embed,
cache_save=self.cache_save
)
return emb_dict
def _encode_structure(self, sequences: List[str], re_embed: bool = False) -> Dict[str, Tuple]:
"""Encode structure with ESMFold"""
feat_list, coor_list = self.esmfold_encoder.forward(
pd.DataFrame({'hla': sequences}),
'hla',
device=str(self.device),
re_embed=re_embed,
)
struct_dict = {
seq: (feat, coor)
for seq, feat, coor in zip(sequences, feat_list, coor_list)
}
return struct_dict
def train(
self,
df_train: pd.DataFrame,
df_val: pd.DataFrame,
epochs: int = 100,
batch_size: int = 256,
lr: float = 1e-4,
patience: int = 5,
num_workers: int = 8,
fold_id: Optional[int] = None
) -> Dict[str, List[float]]:
"""
Train the model
Args:
df_train: Training data
df_val: Validation data
epochs: Number of epochs
batch_size: Batch size
lr: Learning rate
patience: Early stopping patience
num_workers: Number of data loading workers
fold_id: Fold identifier for saving (None for single model)
Returns:
Dictionary with training history
"""
# Check if embeddings are prepared
if self.phys_dict is None or self.esm2_dict is None or self.struct_dict is None:
raise ValueError("Embeddings not prepared! Call prepare_embeddings() first.")
# Create datasets
print("Creating datasets...")
train_dataset = PepHLA_Dataset(df_train, self.phys_dict, self.esm2_dict, self.struct_dict)
val_dataset = PepHLA_Dataset(df_val, self.phys_dict, self.esm2_dict, self.struct_dict)
train_loader = torch.utils.data.DataLoader(
train_dataset,
batch_size=batch_size,
shuffle=True,
num_workers=num_workers,
collate_fn=peptide_hla_collate_fn,
pin_memory=True
)
val_loader = torch.utils.data.DataLoader(
val_dataset,
batch_size=batch_size,
shuffle=False,
num_workers=num_workers,
collate_fn=peptide_hla_collate_fn,
pin_memory=True
)
# Optimizer and early stopping
optimizer = torch.optim.AdamW(self.model.parameters(), lr=lr)
# Model save path for this fold
save_path = self.model_save_path if fold_id is None else \
self.model_save_path.replace('.pt', f'_fold{fold_id}.pt')
early_stopping = EarlyStopping(
patience=patience,
save_path=save_path
)
# Training history
history = {
'train_loss': [],
'val_loss': [],
'val_auc': [],
'val_prc': []
}
fold_str = f"Fold {fold_id}" if fold_id is not None else "Single model"
print(f"\nStarting training for {epochs} epochs [{fold_str}]...")
print("=" * 70)
for epoch in range(epochs):
# Training
self.model.train()
train_loss = 0.0
train_batches = 0
train_iter = tqdm(train_loader, desc=f"Epoch {epoch+1}/{epochs} [Train]", leave=False, ncols=80)
for batch in train_iter:
optimizer.zero_grad()
probs, loss, _, _ = self.model(batch)
loss.backward()
optimizer.step()
train_loss += loss.item()
train_batches += 1
train_loss /= train_batches
# Validation
self.model.eval()
val_loss = 0.0
val_preds = []
val_labels = []
val_batches = 0
with torch.no_grad():
val_iter = tqdm(val_loader, desc=f"Epoch {epoch+1}/{epochs} [Val]", leave=False, ncols=80)
for batch in val_iter:
probs, loss, _, _ = self.model(batch)
val_loss += loss.item()
val_batches += 1
val_preds.extend(probs)
val_labels.extend(batch['label'])
val_auc = roc_auc_score(val_labels, val_preds)
val_loss /= val_batches
val_prc = average_precision_score(val_labels, val_preds)
# Record history
history['train_loss'].append(train_loss)
history['val_loss'].append(val_loss)
history['val_auc'].append(val_auc)
history['val_prc'].append(val_prc)
# Print metrics
print(f"[{fold_str}] Epoch [{epoch+1}/{epochs}] | "
f"Train Loss: {train_loss:.4f} | "
f"Val Loss: {val_loss:.4f} | "
f"Val AUC: {val_auc:.4f} | "
f"Val PRC: {val_prc:.4f}")
# Early stopping
early_stopping(val_prc, self.model)
if early_stopping.early_stop:
print(f"\n[{fold_str}] Early stopping triggered at epoch {epoch+1}!")
break
# Load best model
print(f"\n[{fold_str}] Loading best model from {save_path}...")
self.model.load_state_dict(torch.load(save_path))
print("=" * 70)
print(f"✓ Training completed for {fold_str}!")
return history
def train_kfold(
self,
train_folds: List[Tuple[pd.DataFrame, pd.DataFrame]],
epochs: int = 100,
batch_size: int = 256,
lr: float = 1e-4,
patience: int = 5,
num_workers: int = 8
) -> List[Dict[str, List[float]]]:
"""
Train K-fold cross-validation models
Args:
train_folds: List of (train_df, val_df) tuples for each fold
epochs: Number of epochs per fold
batch_size: Batch size
lr: Learning rate
patience: Early stopping patience
num_workers: Number of data loading workers
Returns:
List of training histories for each fold
"""
num_folds = len(train_folds)
all_histories = []
print("\n" + "=" * 70)
print(f"Starting {num_folds}-Fold Cross-Validation Training")
print("=" * 70)
for fold_id, (df_train, df_val) in enumerate(train_folds):
print(f"\n{'='*70}")
print(f"Training Fold {fold_id+1}/{num_folds}")
print(f"Train: {len(df_train)} samples | Val: {len(df_val)} samples")
print(f"{'='*70}")
self._set_seed(fold_id + self.seed) # Different seed for each fold
# Reinitialize model for this fold
self.model = PeptideHLABindingPredictor(
pep_dim=self.model.pep_dim,
hla_dim=self.model.hla_dim,
bilinear_dim=self.model.bilinear_dim,
loss_fn=self.loss_fn_name,
alpha=self.alpha,
gamma=self.gamma,
device=str(self.device),
pos_weights=self.pos_weights
).to(self.device)
# Train this fold
history = self.train(
df_train,
df_val,
epochs=epochs,
batch_size=batch_size,
lr=lr,
patience=patience,
num_workers=num_workers,
fold_id=fold_id
)
all_histories.append(history)
print("\n" + "=" * 70)
print(f"✓ All {num_folds} folds training completed!")
print("=" * 70)
# Print summary
print("\nCross-Validation Summary:")
print("-" * 70)
for fold_id, history in enumerate(all_histories):
best_auc = max(history['val_auc'])
best_epoch = history['val_auc'].index(best_auc) + 1
print(f"Fold {fold_id}: Best Val AUC = {best_auc:.4f} (Epoch {best_epoch})")
mean_auc = np.mean([max(h['val_auc']) for h in all_histories])
std_auc = np.std([max(h['val_auc']) for h in all_histories])
print("-" * 70)
print(f"Mean Val AUC: {mean_auc:.4f} ± {std_auc:.4f}")
print("=" * 70 + "\n")
return all_histories
def predict(
self,
df: pd.DataFrame,
batch_size: int = 256,
return_probs: bool = True,
return_attn: bool = False,
use_kfold: bool = False,
num_folds: Optional[int] = None,
ensemble_method: str = 'mean',
num_workers: int = 8
) -> np.ndarray:
"""
Make predictions on a dataset
Args:
df: DataFrame with peptide and HLA_full columns
batch_size: Batch size for inference
return_probs: If True, return probabilities; else return binary predictions
use_kfold: If True, use ensemble of K models
num_folds: Number of folds (required if use_kfold=True)
ensemble_method: 'mean' or 'median' for ensemble
Returns:
Array of predictions
"""
# Check if embeddings are prepared
if self.phys_dict is None or self.esm2_dict is None or self.struct_dict is None:
raise ValueError("Embeddings not prepared! Call prepare_embeddings() first.")
if use_kfold:
if num_folds is None:
raise ValueError("num_folds must be specified when use_kfold=True")
return self._predict_ensemble(
df,
batch_size,
num_folds,
ensemble_method,
return_probs,
return_attn,
num_workers
)
else:
# load single model
print(f"\nLoading model from {self.model_save_path} for prediction...")
self.model.load_state_dict(torch.load(self.model_save_path, map_location=self.device), strict=False)
# Single model prediction
return self._predict_single(df, batch_size, return_probs, return_attn, num_workers)
def _pad_attention(self, attns: List[np.ndarray]) -> np.ndarray:
"""Pad attention maps to the same length"""
max_len = max(a.shape[1] for a in attns)
attns_padded = []
for a in attns:
padding = max_len - a.shape[1]
pad_width_3d = ((0, 0), # 不填充 H 维度
(0, padding), # 填充 Lv 维度的末尾
(0, 0)) # 不填充 Lq 维度
attns_padded.append(np.pad(a, pad_width_3d, mode='constant', constant_values=0.0))
return np.concatenate(attns_padded, axis=0)
def _predict_single(
self,
df: pd.DataFrame,
batch_size: int,
return_probs: bool,
return_attn: bool = False,
num_workers: int = 8
) -> np.ndarray:
"""Single model prediction"""
self.model.eval()
dataset = PepHLA_Dataset(df, self.phys_dict, self.esm2_dict, self.struct_dict)
loader = torch.utils.data.DataLoader(
dataset,
batch_size=batch_size,
shuffle=False,
num_workers=num_workers,
collate_fn=peptide_hla_collate_fn,
pin_memory=True
)
preds = []
attns = []
with torch.no_grad():
for batch in tqdm(loader, desc="Predicting"):
probs, loss, attn, _ = self.model(batch)
preds.extend(probs.tolist())
if return_attn:
attns.append(attn)
preds = np.array(preds)
if not return_probs:
preds = (preds >= 0.5).astype(int)
# padding attns to the same length
if not return_attn:
return preds, None
else:
return preds, self._pad_attention(attns)
def _predict_ensemble(
self,
df: pd.DataFrame,
batch_size: int,
num_folds: int,
ensemble_method: str,
return_probs: bool,
return_attn: bool = False,
num_workers: int = 8
) -> np.ndarray:
"""Ensemble prediction using K-fold models"""
print(f"\nEnsemble prediction using {num_folds} models...")
print(f"Ensemble method: {ensemble_method}")
all_preds = []
all_attns = []
for fold_id in range(num_folds):
# Load fold model
fold_model_path = self.model_save_path.replace('.pt', f'_fold{fold_id}.pt')
if not os.path.exists(fold_model_path):
print(f"⚠ Warning: {fold_model_path} not found, skipping...")
continue
print(f"Loading model from {fold_model_path}...")
self.model.load_state_dict(torch.load(fold_model_path, map_location=self.device), strict=False)
# Predict with this fold
if not return_attn:
fold_preds, _ = self._predict_single(df, batch_size, return_probs=True, num_workers=num_workers)
else:
fold_preds, attn_padded = self._predict_single(df, batch_size, return_probs=True, return_attn=True, num_workers=num_workers)
all_attns.append(attn_padded)
all_preds.append(fold_preds)
if len(all_preds) == 0:
raise ValueError("No fold models found!")
# Ensemble predictions
all_preds = np.array(all_preds) # [num_folds, num_samples]
if ensemble_method == 'mean':
ensemble_preds = np.mean(all_preds, axis=0)
elif ensemble_method == 'median':
ensemble_preds = np.median(all_preds, axis=0)
else:
raise ValueError(f"Unknown ensemble method: {ensemble_method}")
print(f"✓ Ensemble prediction completed using {len(all_preds)} models")
if not return_probs:
ensemble_preds = (ensemble_preds >= 0.5).astype(int)
if not return_attn:
return ensemble_preds, None
else:
# num_attn_each_fold = attns_padded.shape[0] // len(all_preds)
# # average attns across folds
# attns_padded = attns_padded.reshape(len(all_preds), num_attn_each_fold, attns_padded.shape[1], attns_padded.shape[2])
# attns_padded = np.mean(attns_padded, axis=1)
return ensemble_preds, self._pad_attention(all_attns)
def evaluate(
self,
df: pd.DataFrame,
batch_size: int = 256,
threshold: float = 0.5,
use_kfold: bool = False,
num_folds: Optional[int] = None,
ensemble_method: str = 'mean',
num_workers: int = 8
) -> Dict[str, float]:
"""
Evaluate model on a dataset
Args:
df: DataFrame with peptide, HLA_full, and label columns
batch_size: Batch size for inference
threshold: Classification threshold
use_kfold: If True, use ensemble of K models
num_folds: Number of folds (required if use_kfold=True)
ensemble_method: 'mean' or 'median' for ensemble
Returns:
Dictionary of metrics
"""
y_true = df['label'].values
y_prob, _ = self.predict(
df,
batch_size=batch_size,
return_probs=True,
use_kfold=use_kfold,
num_folds=num_folds,
ensemble_method=ensemble_method,
num_workers=num_workers
)
y_pred = (y_prob >= threshold).astype(int)
# Calculate metrics
tn, fp, fn, tp = confusion_matrix(y_true, y_pred, labels=[0, 1]).ravel().tolist()
accuracy = (tp + tn) / (tn + fp + fn + tp)
try:
mcc = ((tp*tn) - (fn*fp)) / np.sqrt(float((tp+fn)*(tn+fp)*(tp+fp)*(tn+fn)))
except:
mcc = 0.0
try:
recall = tp / (tp + fn)
except:
recall = 0.0
try:
precision = tp / (tp + fp)
except:
precision = 0.0
try:
f1 = 2 * precision * recall / (precision + recall)
except:
f1 = 0.0
try:
roc_auc = roc_auc_score(y_true, y_prob)
except:
roc_auc = 0.0
try:
# prc
from sklearn.metrics import average_precision_score
prc_auc = average_precision_score(y_true, y_prob)
except:
prc_auc = 0.0
# Print results
model_type = f"{num_folds}-Fold Ensemble ({ensemble_method})" if use_kfold else "Single Model"
print("\n" + "=" * 70)
print(f"Evaluation Results [{model_type}]")
print("=" * 70)
print(f"tn = {tn}, fp = {fp}, fn = {fn}, tp = {tp}")
print(f"y_pred: 0 = {Counter(y_pred)[0]} | 1 = {Counter(y_pred)[1]}")
print(f"y_true: 0 = {Counter(y_true)[0]} | 1 = {Counter(y_true)[1]}")
print(f"AUC: {roc_auc:.4f} | PRC: {prc_auc:.4f} | ACC: {accuracy:.4f} | MCC: {mcc:.4f} | F1: {f1:.4f}")
print(f"Precision: {precision:.4f} | Recall: {recall:.4f}")
print("=" * 70 + "\n")
return y_prob, {
'auc': roc_auc,
'prc': prc_auc,
'accuracy': accuracy,
'mcc': mcc,
'f1': f1,
'precision': precision,
'recall': recall,
'tn': tn,
'fp': fp,
'fn': fn,
'tp': tp
}
def save_model(self, path: str):
"""Save model weights"""
torch.save(self.model.state_dict(), path)
print(f"✓ Model saved to {path}")
def load_model(self, path: str):
"""Load model weights"""
self.model.load_state_dict(torch.load(path, map_location=self.device), strict=False)
print(f"✓ Model loaded from {path}")
# ============================================================================
# -*- coding: utf-8 -*-
import os
import numpy as np
import pandas as pd
from collections import Counter
from tqdm import tqdm
import torch
from sklearn.metrics import roc_auc_score, confusion_matrix
class StriMap_TCRpHLA:
"""
Structure-informed TCR(α/β)–peptide–HLA Binding Prediction
- Reuses encoders from StriMap_pHLA (phys, ESM2, ESMFold)
- Precomputes peptide–HLA features using pretrained StriMap_pHLA.model (PeptideHLABindingPredictor)
and injects them into batch during training/inference.
"""
def __init__(
self,
pep_hla_system = None, # already-initialized and pretrained
device: str = 'cuda:0',
model_save_path: str = 'best_model_tcrpHLA.pt',
tcr_dim: int = 256,
pep_dim: int = 256,
hla_dim: int = 256,
bilinear_dim: int = 256,
loss_fn: str = 'bce',
alpha: float = 0.5,
gamma: float = 2.0,
resample_negatives: bool = False,
seed: int = 1,
pos_weights: Optional[float] = None
):
self.device = torch.device(device if torch.cuda.is_available() else 'cpu')
self.model_save_path = model_save_path
self.seed = seed
self.alpha = alpha
self.gamma = gamma
self.loss_fn_name = loss_fn
self.resample_negatives = resample_negatives
self.pos_weights = pos_weights
# seed
self._set_seed(seed)
if pep_hla_system is None:
raise ValueError("`pep_hla_system` must be provided — pass a trained StriMap_pHLA instance.")
# Reuse encoders from StriMap_pHLA
self.phys_encoder = pep_hla_system.phys_encoder
self.esm2_encoder = pep_hla_system.esm2_encoder
self.esmfold_encoder= pep_hla_system.esmfold_encoder
self.pep_hla_model = pep_hla_system.model # PeptideHLABindingPredictor with encode_peptide_hla()
# Initialize TCR–pHLA model
self.model = TCRPeptideHLABindingPredictor(
tcr_dim=tcr_dim,
pep_dim=pep_dim,
hla_dim=hla_dim,
bilinear_dim=bilinear_dim,
loss_fn=self.loss_fn_name,
alpha=self.alpha,
gamma=self.gamma,
pos_weights=self.pos_weights,
device=str(self.device),
).to(self.device)
# Embedding caches
self.phys_dict = None
self.esm2_dict = None
self.struct_dict = None
self.pep_hla_feat_dict = {}
print(f"✓ StriMap_TCRpHLA initialized on {self.device}")
# -------------------- utils --------------------
def _set_seed(self, seed: int):
np.random.seed(seed)
torch.manual_seed(seed)
torch.cuda.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
torch.backends.cudnn.benchmark = False
torch.backends.cudnn.deterministic = True
# -------------------- encoders --------------------
def _encode_phys(self, sequences):
emb_dict = {}
batch_size = 256
for i in tqdm(range(0, len(sequences), batch_size), desc="Phys encoding (TCRpHLA)"):
batch = sequences[i:i+batch_size]
embs = self.phys_encoder(batch).cpu() # [B, L, D]
for seq, emb in zip(batch, embs):
emb_dict[seq] = emb
return emb_dict
def save_model(self, path: str):
torch.save(self.model.state_dict(), path)
print(f"✓ Model saved to {path}")
def load_model(self, path: str):
"""Load model weights"""
self.model.load_state_dict(torch.load(path, map_location=self.device))
print(f"✓ Model loaded from {path}")
def _encode_esm2(self, sequences, prefix: str, re_embed: bool=False):
df_tmp = pd.DataFrame({'seq': sequences})
return self.esm2_encoder.forward(
df_tmp, seq_col='seq', prefix=prefix, batch_size=128, re_embed=re_embed
)
def _encode_structure(self, sequences, prefix: str, re_embed: bool=False):
feat_list, coor_list = self.esmfold_encoder.forward(
pd.DataFrame({prefix: sequences}), prefix, device=str(self.device), re_embed=re_embed
)
return {seq: (feat, coor) for seq, feat, coor in zip(sequences, feat_list, coor_list)}
# -------------------- public: prepare embeddings --------------------
def prepare_embeddings(self, df: pd.DataFrame, force_recompute: bool=False):
"""
Prepare per-residue encodings for TCRα, TCRβ, peptide, and HLA.
Peptide structure is computed via ESMFold as requested.
"""
all_tcra = sorted(set(df['tcra'].astype(str)))
all_tcrb = sorted(set(df['tcrb'].astype(str)))
all_peps = sorted(set(df['peptide'].astype(str)))
all_hlas = sorted(set(df['HLA_full'].astype(str)))
self.max_pep_len = max(len(p) for p in all_peps)
print(f"\nPreparing embeddings:")
print(f" - TCRα: {len(all_tcra)} | TCRβ: {len(all_tcrb)} | peptides: {len(all_peps)} | HLAs: {len(all_hlas)}\n")
self.phys_dict = {
'tcra': self._encode_phys(all_tcra),
'tcrb': self._encode_phys(all_tcrb),
'pep': self._encode_phys(all_peps),
'hla': self._encode_phys(all_hlas)
}
self.esm2_dict = {
'tcra': self._encode_esm2(all_tcra, prefix='tcra', re_embed=force_recompute),
'tcrb': self._encode_esm2(all_tcrb, prefix='tcrb', re_embed=force_recompute),
'pep': self._encode_esm2(all_peps, prefix='pep', re_embed=force_recompute),
'hla': self._encode_esm2(all_hlas, prefix='hla', re_embed=force_recompute)
}
# Move everything in phys_dict and esm2_dict to CPU
for d in [self.phys_dict, self.esm2_dict]:
for k1 in d.keys(): # tcra / tcrb / pep / hla
for k2 in d[k1].keys(): # actual sequences
if torch.is_tensor(d[k1][k2]):
d[k1][k2] = d[k1][k2].cpu()
torch.cuda.empty_cache()
# IMPORTANT: include peptide structure via ESMFold
self.struct_dict = {
'tcra': self._encode_structure(all_tcra, prefix='tcra', re_embed=force_recompute),
'tcrb': self._encode_structure(all_tcrb, prefix='tcrb', re_embed=force_recompute),
'pep': self._encode_structure(all_peps, prefix='pep', re_embed=force_recompute),
'hla': self._encode_structure(all_hlas, prefix='hla', re_embed=force_recompute)
}
print("✓ Embeddings prepared for TCRα/β, peptide (with ESMFold), and HLA.")
# Move structure features to CPU
for part in ['tcra', 'tcrb', 'pep', 'hla']:
for seq, (feat, coord) in self.struct_dict[part].items():
self.struct_dict[part][seq] = (feat.cpu(), coord.cpu())
torch.cuda.empty_cache()
print("✓ All embeddings moved to CPU, GPU memory released.")
# -------------------- public: precompute pHLA features --------------------
def prepare_pep_hla_features(self, df: pd.DataFrame):
"""
Precompute peptide-HLA features using pretrained PeptideHLABindingPredictor.
The resulting features are stored in self.pep_hla_feat_dict and later injected into each batch.
"""
assert self.phys_dict is not None and self.esm2_dict is not None and self.struct_dict is not None, \
"Call prepare_embeddings() first."
pairs = {(row['peptide'], row['HLA_full']) for _, row in df.iterrows()}
self.pep_hla_model.eval()
for p in self.pep_hla_model.parameters():
p.requires_grad = False
print(f"\nPrecomputing peptide-HLA features for {len(pairs)} unique pairs...")
with torch.no_grad():
for pep, hla in tqdm(pairs, desc="pHLA features"):
pep_phys = self.phys_dict['pep'][pep].unsqueeze(0).to(self.device)
pep_esm = self.esm2_dict['pep'][pep].unsqueeze(0).to(self.device)
# If your PeptideHLABindingPredictor supports peptide structure, pass it too:
pep_struct, pep_coord = self.struct_dict['pep'][pep]
pep_struct = pep_struct.unsqueeze(0).to(self.device)
pep_coord = pep_coord.unsqueeze(0).to(self.device)
hla_phys = self.phys_dict['hla'][hla].unsqueeze(0).to(self.device)
hla_esm = self.esm2_dict['hla'][hla].unsqueeze(0).to(self.device)
hla_struct, hla_coord = self.struct_dict['hla'][hla]
hla_struct = hla_struct.unsqueeze(0).to(self.device)
hla_coord = hla_coord.unsqueeze(0).to(self.device)
# NOTE: encode_peptide_hla must accept (pep_struct, pep_coord) if you upgraded it;
# otherwise remove those two args.
pep_feat, hla_feat = self.pep_hla_model.encode_peptide_hla(
pep,
pep_phys, pep_esm,
hla_phys, hla_esm,
hla_struct, hla_coord,
max_pep_len=self.max_pep_len
)
self.pep_hla_feat_dict[(pep, hla)] = {
'pep_feat_pretrain': pep_feat.squeeze(0).cpu(), # [Lp, pep_dim]
'hla_feat_pretrain': hla_feat.squeeze(0).cpu() # [Lh, hla_dim]
}
print("✓ Pretrained peptide-HLA features prepared.")
# -------------------- training --------------------
def train(
self,
df_train: pd.DataFrame,
df_val: Optional[pd.DataFrame] = None,
df_test: Optional[pd.DataFrame] = None,
df_neg: Optional[pd.DataFrame] = None,
epochs: int = 100,
batch_size: int = 128,
lr: float = 1e-4,
patience: int = 5,
num_workers: int = 8,
):
"""
Train the TCR-pHLA model.
Args:
df_train: Training data.
df_val: Optional validation data.
df_test: Optional test data for evaluation after each epoch.
df_neg: Optional negative samples for training. Set when resample_negatives=True.
epochs: Number of epochs.
batch_size: Batch size.
lr: Learning rate.
patience: Early stopping patience.
num_workers: Data loading workers.
Returns:
history: Dict containing training and validation metrics.
"""
# ---- Prepare embeddings ----
print("Preparing peptide-HLA features...")
all_dfs = [df for df in [df_train, df_val, df_test, df_neg] if df is not None]
self.prepare_pep_hla_features(pd.concat(all_dfs, axis=0))
# ---- Validation loader (optional) ----
if df_val is not None:
val_ds = TCRPepHLA_Dataset(df_val, self.phys_dict, self.esm2_dict, self.struct_dict, self.pep_hla_feat_dict)
val_loader = torch.utils.data.DataLoader(
val_ds, batch_size=batch_size, shuffle=False, num_workers=num_workers,
collate_fn=tcr_pep_hla_collate_fn, pin_memory=True
)
stopper = EarlyStopping(patience=patience, save_path=self.model_save_path)
else:
val_loader, stopper = None, None
# ---- Optimizer ----
optimizer = torch.optim.AdamW(self.model.parameters(), lr=lr)
# ---- Metric history ----
history = {'train_loss': [], 'train_auc': []}
if df_val is not None:
history.update({'val_loss': [], 'val_auc': [], 'val_prc': []})
print("\nStart training TCR–pHLA model...")
df_train_pos = df_train[df_train['label'] == 1].copy().reset_index(drop=True)
for epoch in range(epochs):
# ---------- Training ----------
if self.resample_negatives:
df_train_neg = negative_sampling_phla(df_train_pos, random_state=epoch)
if df_neg is not None:
df_train_neg = pd.concat([df_train_neg, df_neg], axis=0).reset_index(drop=True)
df_train_resample = pd.concat([df_train_pos, df_train_neg], axis=0).reset_index(drop=True)
train_ds = TCRPepHLA_Dataset(df_train_resample, self.phys_dict, self.esm2_dict, self.struct_dict, self.pep_hla_feat_dict)
else:
train_ds = TCRPepHLA_Dataset(df_train, self.phys_dict, self.esm2_dict, self.struct_dict, self.pep_hla_feat_dict)
train_loader = torch.utils.data.DataLoader(
train_ds, batch_size=batch_size, shuffle=True, num_workers=num_workers,
collate_fn=tcr_pep_hla_collate_fn, pin_memory=True
)
self.model.train()
train_labels, train_preds = [], []
epoch_loss = 0.0
for ibatch, batch in enumerate(tqdm(train_loader, desc=f"Epoch {epoch+1}/{epochs} [Train]")):
optimizer.zero_grad()
probs, loss, _, _ = self.model(batch)
loss.backward()
torch.nn.utils.clip_grad_norm_(self.model.parameters(), max_norm=2.0)
optimizer.step()
epoch_loss += loss.item()
train_labels.extend(batch['label'].cpu().numpy().tolist())
train_preds.extend(probs.detach().cpu().numpy().tolist())
train_auc = roc_auc_score(train_labels, train_preds)
train_loss = epoch_loss / (ibatch + 1)
history['train_loss'].append(train_loss)
history['train_auc'].append(train_auc)
print(f"Epoch {epoch+1}/{epochs} | Train Loss: {train_loss:.4f} | Train AUC: {train_auc:.4f}")
# ---------- Validation ----------
if df_val is not None:
self.model.eval()
val_loss_sum, val_labels, val_preds = 0.0, [], []
with torch.no_grad():
for batch in tqdm(val_loader, desc=f"Epoch {epoch+1}/{epochs} [Val]"):
probs, loss, _, _ = self.model(batch)
val_loss_sum += loss.item()
val_labels.extend(batch['label'].cpu().numpy().tolist())
val_preds.extend(probs.detach().cpu().numpy().tolist())
val_loss = val_loss_sum / len(val_loader)
val_auc = roc_auc_score(val_labels, val_preds)
val_prc = average_precision_score(val_labels, val_preds)
history['val_loss'].append(val_loss)
history['val_auc'].append(val_auc)
history['val_prc'].append(val_prc)
print(f"Epoch {epoch+1}/{epochs} | Val AUC: {val_auc:.4f} | Val PRC: {val_prc:.4f} | Val Loss: {val_loss:.4f}")
stopper(val_auc, self.model)
if stopper.early_stop:
print(f"Early stopping at epoch {epoch+1}")
break
# ---------- Optional Test ----------
if df_test is not None:
test_ds = TCRPepHLA_Dataset(df_test, self.phys_dict, self.esm2_dict, self.struct_dict, self.pep_hla_feat_dict)
test_loader = torch.utils.data.DataLoader(
test_ds, batch_size=batch_size, shuffle=False, num_workers=num_workers,
collate_fn=tcr_pep_hla_collate_fn, pin_memory=True
)
self.model.eval()
test_labels, test_preds = [], []
with torch.no_grad():
for batch in tqdm(test_loader, desc=f"Epoch {epoch+1}/{epochs} [Test]"):
probs, _, _, _ = self.model(batch)
test_labels.extend(batch['label'].cpu().numpy().tolist())
test_preds.extend(probs.detach().cpu().numpy().tolist())
test_auc = roc_auc_score(test_labels, test_preds)
test_prc = average_precision_score(test_labels, test_preds)
print(f"Epoch {epoch+1}/{epochs} | Test AUC: {test_auc:.4f} | Test PRC: {test_prc:.4f}")
# ---- Load best model only if validation used ----
if df_val is not None and os.path.exists(self.model_save_path):
self.model.load_state_dict(torch.load(self.model_save_path, map_location=self.device))
print(f"✓ Training finished. Best model loaded from {self.model_save_path}")
else:
print("✓ Training finished (no validation set used).")
return history
def train_kfold(
self,
train_folds: List[Tuple[pd.DataFrame, pd.DataFrame]],
df_test: Optional[pd.DataFrame] = None,
df_neg: Optional[pd.DataFrame] = None,
epochs: int = 100,
batch_size: int = 128,
lr: float = 1e-4,
patience: int = 8,
num_workers: int = 8,
) -> List[Dict[str, List[float]]]:
"""
K-fold cross-validation training for TCR-pHLA model.
Args:
train_folds: list of (train_df, val_df) tuples for each fold
df_test: optional test data for evaluation after each epoch
df_neg: optional negative samples for training. Set when resample_negatives=True.
epochs: training epochs
batch_size: batch size
lr: learning rate
patience: early stopping patience
num_workers: dataloader workers
Returns:
List of training histories for each fold
"""
num_folds = len(train_folds)
all_histories = []
print("\n" + "=" * 70)
print(f"Starting {num_folds}-Fold Cross-Validation Training (TCR-pHLA)")
print("=" * 70)
for fold_id, (df_train, df_val) in enumerate(train_folds):
print(f"\n{'='*70}")
print(f"Training Fold {fold_id+1}/{num_folds}")
print(f"{'='*70}")
self._set_seed(self.seed + fold_id)
self.model = TCRPeptideHLABindingPredictor(
tcr_dim=self.model.tcr_dim,
pep_dim=self.model.pep_dim,
hla_dim=self.model.hla_dim,
bilinear_dim=self.model.bilinear_dim,
loss_fn=self.loss_fn_name,
alpha=self.alpha,
gamma=self.gamma,
pos_weights=self.pos_weights,
device=str(self.device),
).to(self.device)
fold_save_path = self.model_save_path.replace(".pt", f"_fold{fold_id}.pt")
history = self.train(
df_train=df_train,
df_val=df_val,
df_test=df_test,
df_neg=df_neg,
epochs=epochs,
batch_size=batch_size,
lr=lr,
patience=patience,
num_workers=num_workers,
)
torch.save(self.model.state_dict(), fold_save_path)
print(f"✓ Saved fold {fold_id} model to {fold_save_path}")
all_histories.append(history)
print("\n" + "=" * 70)
print(f"✓ All {num_folds} folds training completed (TCR-pHLA)")
print("=" * 70)
if df_val is not None:
print("\nCross-Validation Summary:")
print("-" * 70)
for fold_id, hist in enumerate(all_histories):
best_auc = max(hist['val_auc'])
best_prc = max(hist['val_prc'])
best_epoch = hist['val_auc'].index(best_auc) + 1
print(f"Fold {fold_id}: Best Val AUC = {best_auc:.4f}, Best Val PRC = {best_prc:.4f}, (Epoch {best_epoch})")
mean_auc = np.mean([max(h['val_auc']) for h in all_histories])
std_auc = np.std([max(h['val_auc']) for h in all_histories])
print("-" * 70)
print(f"Mean Val AUC: {mean_auc:.4f} ± {std_auc:.4f}")
print("=" * 70 + "\n")
return all_histories
# -------------------- single-set predict --------------------
def _predict_single(
self, df: pd.DataFrame,
batch_size: int = 128,
return_probs: bool = True,
num_workers: int = 8
):
self.model.eval()
ds = TCRPepHLA_Dataset(df, self.phys_dict, self.esm2_dict, self.struct_dict, self.pep_hla_feat_dict)
loader = torch.utils.data.DataLoader(
ds,
batch_size=batch_size,
shuffle=False,
collate_fn=tcr_pep_hla_collate_fn,
num_workers=num_workers,
pin_memory=True
)
preds = []
pep_feat_all = []
attn_all = []
with torch.no_grad():
for batch in tqdm(loader, desc="Predicting (TCR-pHLA)"):
probs, _, pep_feature, attn_dict = self.model(batch)
preds.extend(probs.tolist())
pep_feat_all.append(pep_feature)
attn_all.append(attn_dict)
preds = np.array(preds)
if not return_probs:
preds = (preds >= 0.5).astype(int)
return preds, pep_feat_all, attn_all
# ================================================================
# Ensemble prediction
# ================================================================
def _predict_ensemble(
self,
df: pd.DataFrame,
batch_size: int = 128,
num_folds: int = 5,
ensemble_method: str = 'mean',
return_probs: bool = True,
num_workers: int = 8
) -> np.ndarray:
"""
Ensemble prediction using multiple fold models.
"""
print(f"\nEnsemble prediction using {num_folds} TCR–pHLA models...")
print(f"Ensemble method: {ensemble_method}")
pep_feats_folds = []
attn_dict_folds = []
all_preds = []
for fold_id in range(num_folds):
fold_model_path = self.model_save_path.replace(".pt", f"_fold{fold_id}.pt")
if not os.path.exists(fold_model_path):
print(f"⚠ Warning: {fold_model_path} not found, skipping...")
continue
print(f"Loading model from {fold_model_path}...")
self.model.load_state_dict(torch.load(fold_model_path, map_location=self.device), strict=False)
# Predict for this fold
fold_preds, fold_pep_feature, fold_attn_dict = self._predict_single(
df, batch_size=batch_size, return_probs=True, num_workers=num_workers
)
all_preds.append(fold_preds)
pep_feats_folds.append(fold_pep_feature)
attn_dict_folds.append(fold_attn_dict)
if len(all_preds) == 0:
raise ValueError("No fold models found!")
if ensemble_method == 'mean':
ensemble_preds = np.mean(all_preds, axis=0)
elif ensemble_method == 'median':
ensemble_preds = np.median(all_preds, axis=0)
else:
raise ValueError(f"Unknown ensemble method: {ensemble_method}")
print(f"✓ Ensemble prediction completed using {len(all_preds)} folds")
if not return_probs:
ensemble_preds = (ensemble_preds >= 0.5).astype(int)
return ensemble_preds, pep_feats_folds, attn_dict_folds
# ================================================================
# Unified predict() with ensemble support
# ================================================================
def predict(
self,
df: pd.DataFrame,
batch_size: int = 128,
return_probs: bool = True,
use_kfold: bool = False,
num_folds: Optional[int] = None,
ensemble_method: str = 'mean',
num_workers: int = 8
) -> Tuple[np.ndarray, List, List]:
"""
Predict binding probabilities or binary labels.
If use_kfold=True, averages predictions across fold models.
"""
print('Preparing peptide-HLA features for prediction set...')
self.prepare_pep_hla_features(df)
if use_kfold:
if num_folds is None:
raise ValueError("num_folds must be specified when use_kfold=True")
return self._predict_ensemble(
df=df,
batch_size=batch_size,
num_folds=num_folds,
ensemble_method=ensemble_method,
return_probs=return_probs,
num_workers=num_workers
)
else:
return self._predict_single(df, batch_size=batch_size, return_probs=return_probs, num_workers=num_workers)
# ================================================================
# Unified evaluate() with ensemble support
# ================================================================
def evaluate(
self,
df: pd.DataFrame,
batch_size: int = 128,
threshold: float = 0.5,
use_kfold: bool = False,
num_folds: Optional[int] = None,
ensemble_method: str = 'mean',
num_workers: int = 8
) -> Dict[str, float]:
"""
Evaluate model performance on a dataset.
If use_kfold=True, performs ensemble evaluation across folds.
"""
y_true = df['label'].values
y_prob, all_pep_features, merged_attn = self.predict(
df,
batch_size=batch_size,
return_probs=True,
use_kfold=use_kfold,
num_folds=num_folds,
ensemble_method=ensemble_method,
num_workers=num_workers
)
y_pred = (y_prob >= threshold).astype(int)
tn, fp, fn, tp = confusion_matrix(y_true, y_pred, labels=[0, 1]).ravel().tolist()
accuracy = (tp + tn) / (tn + fp + fn + tp + 1e-9)
try:
mcc = ((tp*tn) - (fn*fp)) / np.sqrt(float((tp+fn)*(tn+fp)*(tp+fp)*(tn+fn)) + 1e-9)
except:
mcc = 0.0
recall = tp / (tp + fn + 1e-9)
precision = tp / (tp + fp + 1e-9)
f1 = 2 * precision * recall / (precision + recall + 1e-9)
try:
auc = roc_auc_score(y_true, y_prob, max_fpr=0.1)
except:
auc = 0.0
print("\n" + "=" * 70)
print(f"Evaluation Results [{'K-Fold Ensemble' if use_kfold else 'Single Model'}]")
print("=" * 70)
print(f"tn={tn}, fp={fp}, fn={fn}, tp={tp}")
print(f"AUC={auc:.4f} | ACC={accuracy:.4f} | MCC={mcc:.4f} | F1={f1:.4f} | P={precision:.4f} | R={recall:.4f}")
print("=" * 70 + "\n")
return dict(
auc=auc, accuracy=accuracy, mcc=mcc, f1=f1,
precision=precision, recall=recall,
tn=tn, fp=fp, fn=fn, tp=tp
) |