beaver.py

   1 #!/usr/bin/env python
   2
   3 # Any copyright is dedicated to the Public Domain.
   4 # https://creativecommons.org/publicdomain/zero/1.0/
   5
   6 # Written by Francois Fleuret <francois@fleuret.org>
   7
   8 # torch.backends.cuda.matmul.allow_tf23
   9 # torch.autocast(torch.bfloat16)
  10
  11 import math, sys, argparse, time, tqdm, itertools, os
  12
  13 import torch, torchvision
  14 from torch import nn
  15 from torch.nn import functional as F
  16
  17 import mygpt, tensorstack
  18
  19 ######################################################################
  20
  21 if torch.cuda.is_available():
  22     device = torch.device("cuda")
  23     torch.backends.cuda.matmul.allow_tf32 = True
  24 else:
  25     device = torch.device("cpu")
  26
  27 ######################################################################
  28
  29 parser = argparse.ArgumentParser(description="A maze shortest path solving with a GPT.")
  30
  31 parser.add_argument("--log_filename", type=str, default="train.log")
  32
  33 parser.add_argument("--result_dir", type=str, default="results_default")
  34
  35 parser.add_argument("--seed", type=int, default=0)
  36
  37 parser.add_argument("--nb_epochs", type=int, default=25)
  38
  39 parser.add_argument("--nb_train_samples", type=int, default=200000)
  40
  41 parser.add_argument("--nb_test_samples", type=int, default=50000)
  42
  43 parser.add_argument("--batch_size", type=int, default=25)
  44
  45 parser.add_argument("--optim", type=str, default="adam")
  46
  47 parser.add_argument("--learning_rate", type=float, default=1e-3)
  48
  49 parser.add_argument(
  50     "--learning_rate_schedule", type=str, default="10: 2e-4,20: 4e-5,30: 8e-6"
  51 )
  52
  53 parser.add_argument("--dim_model", type=int, default=512)
  54
  55 parser.add_argument("--dim_keys", type=int, default=64)
  56
  57 parser.add_argument("--dim_hidden", type=int, default=2048)
  58
  59 parser.add_argument("--nb_heads", type=int, default=8)
  60
  61 parser.add_argument("--nb_blocks", type=int, default=12)
  62
  63 parser.add_argument("--dropout", type=float, default=0.1)
  64
  65 parser.add_argument("--deterministic_synthesis", action="store_true", default=False)
  66
  67 parser.add_argument("--no_checkpoint", action="store_true", default=False)
  68
  69 parser.add_argument("--overwrite_results", action="store_true", default=False)
  70
  71 parser.add_argument("--one_shot", action="store_true", default=False)
  72
  73 parser.add_argument("--checkpoint_name", type=str, default="checkpoint.pth")
  74
  75 ##############################
  76 # maze options
  77
  78 parser.add_argument("--maze_height", type=int, default=13)
  79
  80 parser.add_argument("--maze_width", type=int, default=21)
  81
  82 parser.add_argument("--maze_nb_walls", type=int, default=15)
  83
  84 parser.add_argument("--oneshot_mode", type=str, default="head")
  85
  86 ######################################################################
  87
  88 args = parser.parse_args()
  89
  90 try:
  91     os.mkdir(args.result_dir)
  92 except FileExistsError:
  93     if not args.overwrite_results:
  94         print(f"result directory {args.result_dir} already exists")
  95         exit(1)
  96
  97 log_file = open(os.path.join(args.result_dir, args.log_filename), "a")
  98
  99 if args.seed >= 0:
 100     # torch.backends.cudnn.deterministic = True
 101     # torch.backends.cudnn.benchmark = False
 102     # torch.use_deterministic_algorithms(True)
 103     torch.manual_seed(args.seed)
 104     if torch.cuda.is_available():
 105         torch.cuda.manual_seed_all(args.seed)
 106
 107 ######################################################################
 108
 109
 110 def log_string(s):
 111     t = time.strftime("%Y%m%d-%H:%M:%S ", time.localtime())
 112
 113     if log_file is not None:
 114         log_file.write(t + s + "\n")
 115         log_file.flush()
 116
 117     print(t + s)
 118     sys.stdout.flush()
 119
 120
 121 for n in vars(args):
 122     log_string(f"args.{n} {getattr(args, n)}")
 123
 124 ######################################################################
 125
 126
 127 # ar_mask is a Boolean matrix of same shape as input, with 1s on the
 128 # tokens that should be generated
 129
 130
 131 def masked_inplace_autoregression(model, batch_size, input, ar_mask):
 132     for input, ar_mask in zip(input.split(batch_size), ar_mask.split(batch_size)):
 133         i = (ar_mask.sum(0) > 0).nonzero()
 134         if i.min() > 0:
 135             # Needed to initialize the model's cache
 136             model(mygpt.BracketedSequence(input, 0, i.min()))
 137         for s in range(i.min(), i.max() + 1):
 138             output = model(mygpt.BracketedSequence(input, s, 1)).x
 139             logits = output[:, s]
 140             if args.deterministic_synthesis:
 141                 t_next = logits.argmax(1)
 142             else:
 143                 dist = torch.distributions.categorical.Categorical(logits=logits)
 144                 t_next = dist.sample()
 145             input[:, s] = ar_mask[:, s] * t_next + (1 - ar_mask[:, s]) * input[:, s]
 146
 147
 148 ######################################################################
 149
 150
 151 def compute_perplexity(model, split="train"):
 152     with torch.autograd.no_grad():
 153         t = model.training
 154         model.eval()
 155
 156         nb_samples, acc_loss = 0, 0.0
 157
 158         for input in task.batches(split=split):
 159             input = input.to(device)
 160
 161             output = model(mygpt.BracketedSequence(input)).x
 162             loss = F.cross_entropy(output.transpose(1, 2), input)
 163             acc_loss += loss.item() * input.size(0)
 164             nb_samples += input.size(0)
 165
 166         model.train(t)
 167
 168         return math.exp(min(100, acc_loss / nb_samples))
 169
 170
 171 ######################################################################
 172
 173
 174 def one_shot(gpt, task):
 175     t = gpt.training
 176     gpt.eval()
 177     dim_in = args.dim_model * (args.nb_blocks * 2 if args.oneshot_mode == "deep" else 1)
 178     model = nn.Sequential(
 179         nn.Linear(dim_in, args.dim_model),
 180         nn.ReLU(),
 181         nn.Linear(args.dim_model, args.dim_model),
 182         nn.ReLU(),
 183         nn.Linear(args.dim_model, 4),
 184     ).to(device)
 185
 186     for n_epoch in range(args.nb_epochs):
 187         learning_rate = learning_rate_schedule[n_epoch]
 188         optimizer = torch.optim.Adam(model.parameters(), lr=learning_rate)
 189
 190         acc_train_loss, nb_train_samples = 0, 0
 191         for input, targets in task.policy_batches(split="train"):
 192             output_gpt = gpt(mygpt.BracketedSequence(input), mode=args.oneshot_mode).x
 193             output = model(output_gpt)
 194             targets = targets * (input.unsqueeze(-1) == maze.v_empty)
 195             output = output * (input.unsqueeze(-1) == maze.v_empty)
 196             # loss = (output.softmax(-1) - targets).abs().max(-1).values.mean()
 197             loss = (
 198                 -(output.log_softmax(-1) * targets).sum()
 199                 / (input == maze.v_empty).sum()
 200             )
 201             acc_train_loss += loss.item() * input.size(0)
 202             nb_train_samples += input.size(0)
 203
 204             optimizer.zero_grad()
 205             loss.backward()
 206             optimizer.step()
 207
 208         acc_test_loss, nb_test_samples = 0, 0
 209         for input, targets in task.policy_batches(split="test"):
 210             output_gpt = gpt(mygpt.BracketedSequence(input), mode=args.oneshot_mode).x
 211             output = model(output_gpt)
 212             targets = targets * (input.unsqueeze(-1) == maze.v_empty)
 213             output = output * (input.unsqueeze(-1) == maze.v_empty)
 214             # loss = (output.softmax(-1) - targets).abs().max(-1).values.mean()
 215             loss = (
 216                 -(output.log_softmax(-1) * targets).sum()
 217                 / (input == maze.v_empty).sum()
 218             )
 219             acc_test_loss += loss.item() * input.size(0)
 220             nb_test_samples += input.size(0)
 221
 222         log_string(
 223             f"diff_ce {n_epoch} train {acc_train_loss/nb_train_samples} test {acc_test_loss/nb_test_samples}"
 224         )
 225
 226         # -------------------
 227         input = task.test_input[:32, : task.height * task.width]
 228         targets = task.test_policies[:32]
 229         output_gpt = gpt(mygpt.BracketedSequence(input), mode=args.oneshot_mode).x
 230         output = model(output_gpt)
 231         # losses = (-output.log_softmax(-1) * targets + targets.xlogy(targets)).sum(-1)
 232         # losses = losses * (input == maze.v_empty)
 233         # losses = losses / losses.max()
 234         # losses = (output.softmax(-1) - targets).abs().max(-1).values
 235         # losses = (losses >= 0.05).float()
 236         losses = (
 237             (F.one_hot(output.argmax(-1), num_classes=4) * targets).sum(-1) == 0
 238         ).float()
 239         losses = losses.reshape(-1, args.maze_height, args.maze_width)
 240         input = input.reshape(-1, args.maze_height, args.maze_width)
 241         maze.save_image(
 242             os.path.join(
 243                 args.result_dir, f"oneshot_{args.oneshot_mode}_{n_epoch:04d}.png"
 244             ),
 245             mazes=input,
 246             score_paths=losses,
 247         )
 248         # -------------------
 249
 250     gpt.train(t)
 251
 252
 253 ######################################################################
 254
 255
 256 class Task:
 257     def batches(self, split="train"):
 258         pass
 259
 260     def vocabulary_size(self):
 261         pass
 262
 263     def produce_results(self, n_epoch, model):
 264         pass
 265
 266
 267 ######################################################################
 268
 269 import maze
 270
 271
 272 class TaskMaze(Task):
 273     def map2seq(self, *m):
 274         return torch.cat([x.flatten(1) for x in m], 1)
 275
 276     def seq2map(self, s):
 277         s = s.reshape(s.size(0), -1, self.height, self.width)
 278         return (s[:, k] for k in range(s.size(1)))
 279
 280     def __init__(
 281         self,
 282         nb_train_samples,
 283         nb_test_samples,
 284         batch_size,
 285         height,
 286         width,
 287         nb_walls,
 288         device=torch.device("cpu"),
 289     ):
 290         self.batch_size = batch_size
 291         self.height = height
 292         self.width = width
 293         self.device = device
 294
 295         train_mazes, train_paths, train_policies = maze.create_maze_data(
 296             nb_train_samples,
 297             height=height,
 298             width=width,
 299             nb_walls=nb_walls,
 300             progress_bar=lambda x: tqdm.tqdm(x, dynamic_ncols=True, desc=f"data-train"),
 301         )
 302         self.train_input = self.map2seq(train_mazes.to(device), train_paths.to(device))
 303         self.train_policies = train_policies.flatten(-2).permute(0, 2, 1).to(device)
 304
 305         test_mazes, test_paths, test_policies = maze.create_maze_data(
 306             nb_test_samples,
 307             height=height,
 308             width=width,
 309             nb_walls=nb_walls,
 310             progress_bar=lambda x: tqdm.tqdm(x, dynamic_ncols=True, desc=f"data-test"),
 311         )
 312         self.test_input = self.map2seq(test_mazes.to(device), test_paths.to(device))
 313         self.test_policies = test_policies.flatten(-2).permute(0, 2, 1).to(device)
 314
 315         self.nb_codes = self.train_input.max() + 1
 316
 317     def batches(self, split="train", nb_to_use=-1):
 318         assert split in {"train", "test"}
 319         input = self.train_input if split == "train" else self.test_input
 320         if nb_to_use > 0:
 321             input = input[:nb_to_use]
 322         for batch in tqdm.tqdm(
 323             input.split(self.batch_size), dynamic_ncols=True, desc=f"epoch-{split}"
 324         ):
 325             yield batch
 326
 327     def policy_batches(self, split="train", nb_to_use=-1):
 328         assert split in {"train", "test"}
 329         input = self.train_input if split == "train" else self.test_input
 330         targets = self.train_policies if split == "train" else self.test_policies
 331         input = input[:, : self.height * self.width]
 332         targets = targets * (input != maze.v_wall)[:, :, None]
 333
 334         if nb_to_use > 0:
 335             input = input[:nb_to_use]
 336             targets = targets[:nb_to_use]
 337
 338         for batch in tqdm.tqdm(
 339             zip(input.split(self.batch_size), targets.split(self.batch_size)),
 340             dynamic_ncols=True,
 341             desc=f"epoch-{split}",
 342         ):
 343             yield batch
 344
 345     def vocabulary_size(self):
 346         return self.nb_codes
 347
 348     def compute_error(self, model, split="train", nb_to_use=-1):
 349         nb_total, nb_correct = 0, 0
 350         for input in task.batches(split, nb_to_use):
 351             result = input.clone()
 352             ar_mask = result.new_zeros(result.size())
 353             ar_mask[:, self.height * self.width :] = 1
 354             result *= 1 - ar_mask
 355             masked_inplace_autoregression(model, self.batch_size, result, ar_mask)
 356             mazes, paths = self.seq2map(result)
 357             nb_correct += maze.path_correctness(mazes, paths).long().sum()
 358             nb_total += mazes.size(0)
 359
 360         return nb_total, nb_correct
 361
 362     def produce_results(self, n_epoch, model):
 363         with torch.autograd.no_grad():
 364             t = model.training
 365             model.eval()
 366
 367             train_nb_total, train_nb_correct = self.compute_error(
 368                 model, "train", nb_to_use=1000
 369             )
 370             log_string(
 371                 f"accuracy_train nb_total {train_nb_total} nb_correct {train_nb_correct} accuracy {(100.0*train_nb_correct)/train_nb_total:.02f}%"
 372             )
 373
 374             test_nb_total, test_nb_correct = self.compute_error(
 375                 model, "test", nb_to_use=1000
 376             )
 377             log_string(
 378                 f"accuracy_test nb_total {test_nb_total} nb_correct {test_nb_correct} accuracy {(100.0*test_nb_correct)/test_nb_total:.02f}%"
 379             )
 380
 381             input = self.test_input[:32]
 382             result = input.clone()
 383             ar_mask = result.new_zeros(result.size())
 384             ar_mask[:, self.height * self.width :] = 1
 385             result *= 1 - ar_mask
 386             masked_inplace_autoregression(model, self.batch_size, result, ar_mask)
 387
 388             mazes, paths = self.seq2map(input)
 389             _, predicted_paths = self.seq2map(result)
 390             maze.save_image(
 391                 os.path.join(args.result_dir, f"result_{n_epoch:04d}.png"),
 392                 mazes=mazes,
 393                 target_paths=paths,
 394                 predicted_paths=predicted_paths,
 395                 path_correct=maze.path_correctness(mazes, predicted_paths),
 396             )
 397
 398             model.train(t)
 399
 400
 401 ######################################################################
 402
 403 log_string(f"device {device}")
 404
 405
 406 task = TaskMaze(
 407     nb_train_samples=args.nb_train_samples,
 408     nb_test_samples=args.nb_test_samples,
 409     batch_size=args.batch_size,
 410     height=args.maze_height,
 411     width=args.maze_width,
 412     nb_walls=args.maze_nb_walls,
 413     device=device,
 414 )
 415
 416
 417 vocabulary_size = task.vocabulary_size()
 418
 419 log_string(f"vocabulary_size {vocabulary_size}")
 420
 421 ##############################
 422
 423 model = mygpt.MyGPT(
 424     vocabulary_size=vocabulary_size,
 425     dim_model=args.dim_model,
 426     dim_keys=args.dim_keys,
 427     dim_hidden=args.dim_hidden,
 428     nb_heads=args.nb_heads,
 429     nb_blocks=args.nb_blocks,
 430     causal=True,
 431     dropout=args.dropout,
 432 )
 433
 434 model.to(device)
 435
 436 nb_parameters = sum(p.numel() for p in model.parameters())
 437 log_string(f"nb_parameters {nb_parameters} ({int(nb_parameters/1e6)}M)")
 438
 439 ######################################################################
 440
 441 nb_epochs_finished = 0
 442
 443 if args.no_checkpoint:
 444     log_string(f"not trying to load checkpoint.")
 445
 446 else:
 447     try:
 448         checkpoint_name = os.path.join(args.result_dir, args.checkpoint_name)
 449         checkpoint = torch.load(checkpoint_name)
 450         nb_epochs_finished = checkpoint["nb_epochs_finished"]
 451         model.load_state_dict(checkpoint["model_state"])
 452         torch.set_rng_state(checkpoint["rng_state"])
 453         if torch.cuda.is_available():
 454             torch.cuda.set_rng_state(checkpoint["cuda_rng_state"])
 455
 456         log_string(f"checkpoint loaded with {nb_epochs_finished} epochs finished.")
 457
 458     except FileNotFoundError:
 459         log_string("starting from scratch.")
 460
 461     except:
 462         log_string("error when loading the checkpoint.")
 463         exit(1)
 464
 465 ######################################################################
 466
 467 token_count = 0
 468 for input in task.batches(split="train"):
 469     token_count += F.one_hot(input, num_classes=task.vocabulary_size()).sum((0, 1))
 470 token_probas = token_count / token_count.sum()
 471 entropy = -torch.xlogy(token_probas, token_probas).sum()
 472 train_set_perplexity = math.exp(entropy)
 473
 474 ##############################
 475
 476 if args.learning_rate_schedule == "cos":
 477     learning_rate_schedule = {}
 478     for n_epoch in range(args.nb_epochs):
 479         u = n_epoch / args.nb_epochs * math.pi
 480         learning_rate_schedule[n_epoch] = args.learning_rate * 0.5 * (1 + math.cos(u))
 481 else:
 482     u = {
 483         int(k): float(v)
 484         for k, v in [
 485             tuple(x.split(":")) for x in args.learning_rate_schedule.split(",")
 486         ]
 487     }
 488
 489     learning_rate_schedule = {}
 490     learning_rate = args.learning_rate
 491     for n_epoch in range(args.nb_epochs):
 492         if n_epoch in u:
 493             learning_rate = u[n_epoch]
 494         learning_rate_schedule[n_epoch] = learning_rate
 495
 496 log_string(f"learning_rate_schedule {learning_rate_schedule}")
 497
 498 ##############################
 499
 500 if args.one_shot:
 501     one_shot(model, task)
 502     exit(0)
 503
 504 ##############################
 505
 506 if nb_epochs_finished >= args.nb_epochs:
 507     n_epoch = nb_epochs_finished
 508     train_perplexity = compute_perplexity(model, split="train")
 509     test_perplexity = compute_perplexity(model, split="test")
 510
 511     log_string(
 512         f"perplexity {n_epoch} train_set {train_set_perplexity} train_prediction {train_perplexity} test_prediction {test_perplexity}"
 513     )
 514
 515     task.produce_results(n_epoch, model)
 516
 517     exit(0)
 518
 519 ##############################
 520
 521 for n_epoch in range(nb_epochs_finished, args.nb_epochs):
 522     learning_rate = learning_rate_schedule[n_epoch]
 523
 524     log_string(f"learning_rate {learning_rate}")
 525
 526     if args.optim == "sgd":
 527         optimizer = torch.optim.SGD(model.parameters(), lr=learning_rate)
 528     elif args.optim == "adam":
 529         optimizer = torch.optim.Adam(model.parameters(), lr=learning_rate)
 530     elif args.optim == "adamw":
 531         optimizer = torch.optim.AdamW(model.parameters(), lr=learning_rate)
 532     else:
 533         raise ValueError(f"Unknown optimizer {args.optim}.")
 534
 535     model.train()
 536
 537     nb_train_samples, acc_train_loss = 0, 0.0
 538
 539     for input in task.batches(split="train"):
 540         input = input.to(device)
 541         output = model(mygpt.BracketedSequence(input)).x
 542         loss = F.cross_entropy(output.transpose(1, 2), input)
 543         acc_train_loss += loss.item() * input.size(0)
 544         nb_train_samples += input.size(0)
 545
 546         optimizer.zero_grad()
 547         loss.backward()
 548         optimizer.step()
 549
 550     train_perplexity = math.exp(min(100, acc_train_loss / nb_train_samples))
 551     test_perplexity = compute_perplexity(model, split="test")
 552
 553     log_string(
 554         f"perplexity {n_epoch} train_set {train_set_perplexity} train_prediction {train_perplexity} test_prediction {test_perplexity}"
 555     )
 556
 557     task.produce_results(n_epoch, model)
 558
 559     checkpoint = {
 560         "nb_epochs_finished": n_epoch + 1,
 561         "model_state": model.state_dict(),
 562         "rng_state": torch.get_rng_state(),
 563     }
 564
 565     if torch.cuda.is_available():
 566         checkpoint["cuda_rng_state"] = torch.cuda.get_rng_state()
 567
 568     checkpoint_name = os.path.join(args.result_dir, args.checkpoint_name)
 569     torch.save(checkpoint, checkpoint_name)
 570     log_string(f"saved checkpoint {checkpoint_name}")
 571
 572 ######################################################################