Update.
[picoclvr.git] / main.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 import math, sys, argparse, time, tqdm, os, datetime
9
10 import torch, torchvision
11 from torch import nn
12 from torch.nn import functional as F
13
14 import ffutils
15 import mygpt, tasks, problems
16
17 ######################################################################
18
19 if torch.cuda.is_available():
20     device = torch.device("cuda")
21     torch.backends.cuda.matmul.allow_tf32 = True
22 else:
23     device = torch.device("cpu")
24
25 ######################################################################
26
27 parser = argparse.ArgumentParser(
28     description="An implementation of GPT with cache.",
29     formatter_class=argparse.ArgumentDefaultsHelpFormatter,
30 )
31
32 parser.add_argument(
33     "--task",
34     type=str,
35     default="twotargets",
36     help="file, byheart, learnop, guessop, mixing, memory, twotargets, addition, picoclvr, mnist, maze, snake, stack, expr, rpl, grid, qmlp, escape",
37 )
38
39 parser.add_argument("--log_filename", type=str, default="train.log", help=" ")
40
41 parser.add_argument("--result_dir", type=str, default=None)
42
43 parser.add_argument("--seed", type=int, default=0)
44
45 parser.add_argument("--max_percents_of_test_in_train", type=int, default=1)
46
47 ########################################
48
49 parser.add_argument("--nb_epochs", type=int, default=25)
50
51 parser.add_argument("--batch_size", type=int, default=None)
52
53 parser.add_argument("--nb_train_samples", type=int, default=None)
54
55 parser.add_argument("--nb_test_samples", type=int, default=None)
56
57 parser.add_argument("--optim", type=str, default="adam")
58
59 parser.add_argument("--learning_rate", type=float, default=1e-4)
60
61 parser.add_argument("--learning_rate_schedule", type=str, default="10: 2e-5,30: 4e-6")
62
63 ########################################
64
65 parser.add_argument("--model", type=str, default=None)
66
67 parser.add_argument("--dim_model", type=int, default=None)
68
69 parser.add_argument("--dim_keys", type=int, default=None)
70
71 parser.add_argument("--dim_hidden", type=int, default=None)
72
73 parser.add_argument("--nb_heads", type=int, default=None)
74
75 parser.add_argument("--nb_blocks", type=int, default=None)
76
77 parser.add_argument("--dropout", type=float, default=0.1)
78
79 ########################################
80
81 parser.add_argument("--deterministic_synthesis", action="store_true", default=False)
82
83 parser.add_argument("--no_checkpoint", action="store_true", default=False)
84
85 parser.add_argument("--overwrite_results", action="store_true", default=False)
86
87 parser.add_argument("--checkpoint_name", type=str, default="checkpoint.pth")
88
89 ##############################
90 # filetask
91
92 parser.add_argument("--filetask_train_file", type=str, default=None)
93
94 parser.add_argument("--filetask_test_file", type=str, default=None)
95
96 ##############################
97 # rpl options
98
99 parser.add_argument("--rpl_nb_starting_values", type=int, default=3)
100
101 parser.add_argument("--rpl_max_input", type=int, default=9)
102
103 parser.add_argument("--rpl_prog_len", type=int, default=8)
104
105 parser.add_argument("--rpl_nb_runs", type=int, default=5)
106
107 parser.add_argument("--rpl_no_prog", action="store_true", default=False)
108
109 ##############################
110 # grid options
111
112 parser.add_argument("--grid_size", type=int, default=6)
113
114 parser.add_argument("--grid_fraction_play", type=float, default=0)
115
116 ##############################
117 # picoclvr options
118
119 parser.add_argument("--picoclvr_nb_colors", type=int, default=5)
120
121 parser.add_argument("--picoclvr_height", type=int, default=12)
122
123 parser.add_argument("--picoclvr_width", type=int, default=16)
124
125 parser.add_argument("--picocvlr_prune_properties", type=str, default="none")
126
127 ##############################
128 # Maze options
129
130 parser.add_argument("--maze_height", type=int, default=13)
131
132 parser.add_argument("--maze_width", type=int, default=21)
133
134 parser.add_argument("--maze_nb_walls", type=int, default=15)
135
136 ##############################
137 # Snake options
138
139 parser.add_argument("--snake_height", type=int, default=9)
140
141 parser.add_argument("--snake_width", type=int, default=12)
142
143 parser.add_argument("--snake_nb_colors", type=int, default=5)
144
145 parser.add_argument("--snake_length", type=int, default=200)
146
147 ##############################
148 # Stack options
149
150 parser.add_argument("--stack_nb_steps", type=int, default=100)
151
152 parser.add_argument("--stack_nb_stacks", type=int, default=3)
153
154 parser.add_argument("--stack_nb_digits", type=int, default=3)
155
156 parser.add_argument("--stack_fraction_values_for_train", type=float, default=0.75)
157
158 ##############################
159 # Expr options
160
161 parser.add_argument("--expr_nb_variables", type=int, default=5)
162
163 parser.add_argument("--expr_sequence_length", type=int, default=40)
164
165 parser.add_argument("--expr_operand_max", type=int, default=9)
166
167 parser.add_argument("--expr_result_max", type=int, default=99)
168
169 parser.add_argument("--expr_input_file", type=str, default=None)
170
171 ##############################
172 # Mixing
173
174 parser.add_argument("--mixing_hard", action="store_true", default=False)
175
176 parser.add_argument("--mixing_deterministic_start", action="store_true", default=False)
177
178 ##############################
179 # escape options
180
181 parser.add_argument("--escape_height", type=int, default=5)
182
183 parser.add_argument("--escape_width", type=int, default=7)
184
185 parser.add_argument("--escape_T", type=int, default=25)
186
187 parser.add_argument("--escape_nb_walls", type=int, default=5)
188
189 ######################################################################
190
191 args = parser.parse_args()
192
193 assert args.picocvlr_prune_properties in {"none", "train+eval", "eval"}
194
195 if args.result_dir is None:
196     args.result_dir = f"results_{args.task}"
197
198 ######################################################################
199
200 default_task_args = {
201     "file": {
202         "model": "37M",
203         "batch_size": 25,
204         "nb_train_samples": 250000,
205         "nb_test_samples": 10000,
206     },
207     "addition": {
208         "model": "352M",
209         "batch_size": 25,
210         "nb_train_samples": 250000,
211         "nb_test_samples": 10000,
212     },
213     "byheart": {
214         "model": "37M",
215         "batch_size": 25,
216         "nb_train_samples": 50000,
217         "nb_test_samples": 10000,
218     },
219     "expr": {
220         "model": "352M",
221         "batch_size": 25,
222         "nb_train_samples": 2500000,
223         "nb_test_samples": 10000,
224     },
225     "grid": {
226         "model": "37M",
227         "batch_size": 25,
228         "nb_train_samples": 250000,
229         "nb_test_samples": 10000,
230     },
231     "qmlp": {
232         "model": "37M",
233         "batch_size": 10,
234         "nb_train_samples": 100000,
235         "nb_test_samples": 1000,
236     },
237     "guessop": {
238         "model": "352M",
239         "batch_size": 25,
240         "nb_train_samples": 1000000,
241         "nb_test_samples": 10000,
242     },
243     "learnop": {
244         "model": "37M",
245         "batch_size": 25,
246         "nb_train_samples": 50000,
247         "nb_test_samples": 10000,
248     },
249     "maze": {
250         "model": "37M",
251         "batch_size": 5,
252         "nb_train_samples": 100000,
253         "nb_test_samples": 10000,
254     },
255     "picoclvr": {
256         "model": "37M",
257         "batch_size": 25,
258         "nb_train_samples": 250000,
259         "nb_test_samples": 10000,
260     },
261     "rpl": {
262         "model": "352M",
263         "batch_size": 5,
264         "nb_train_samples": 2500000,
265         "nb_test_samples": 10000,
266     },
267     "snake": {
268         "model": "37M",
269         "batch_size": 25,
270         "nb_train_samples": 250000,
271         "nb_test_samples": 10000,
272     },
273     "stack": {
274         "model": "37M",
275         "batch_size": 25,
276         "nb_train_samples": 100000,
277         "nb_test_samples": 1000,
278     },
279     "twotargets": {
280         "model": "37M",
281         "batch_size": 25,
282         "nb_train_samples": 50000,
283         "nb_test_samples": 10000,
284     },
285     "memory": {
286         "model": "37M",
287         "batch_size": 100,
288         "nb_train_samples": 25000,
289         "nb_test_samples": 1000,
290     },
291     "mixing": {
292         "model": "37M",
293         "batch_size": 25,
294         "nb_train_samples": 250000,
295         "nb_test_samples": 10000,
296     },
297     "mnist": {
298         "model": "37M",
299         "batch_size": 10,
300         "nb_train_samples": 60000,
301         "nb_test_samples": 10000,
302     },
303     "escape": {
304         "model": "37M",
305         "batch_size": 25,
306         "nb_train_samples": 25000,
307         "nb_test_samples": 10000,
308     },
309 }
310
311 if args.task in default_task_args:
312     for k, v in default_task_args[args.task].items():
313         if getattr(args, k) is None:
314             setattr(args, k, v)
315
316 ######################################################################
317
318 default_model_args = {
319     "17K": {
320         "dim_model": 32,
321         "dim_keys": 32,
322         "dim_hidden": 32,
323         "nb_heads": 2,
324         "nb_blocks": 2,
325     },
326     "4M": {
327         "dim_model": 256,
328         "dim_keys": 32,
329         "dim_hidden": 1024,
330         "nb_heads": 4,
331         "nb_blocks": 6,
332     },
333     "37M": {
334         "dim_model": 512,
335         "dim_keys": 64,
336         "dim_hidden": 2048,
337         "nb_heads": 8,
338         "nb_blocks": 12,
339     },
340     "122M": {
341         "dim_model": 768,
342         "dim_keys": 64,
343         "dim_hidden": 2048,
344         "nb_heads": 8,
345         "nb_blocks": 24,
346     },
347     "352M": {
348         "dim_model": 1024,
349         "dim_keys": 64,
350         "dim_hidden": 2048,
351         "nb_heads": 8,
352         "nb_blocks": 48,
353     },
354 }
355
356 if args.model in default_model_args:
357     for k, v in default_model_args[args.model].items():
358         if getattr(args, k) is None:
359             setattr(args, k, v)
360 else:
361     raise ValueError(f"Unknown model {args.model}")
362
363 ######################################################################
364
365 try:
366     os.mkdir(args.result_dir)
367 except FileExistsError:
368     if not args.overwrite_results:
369         print(f"result directory {args.result_dir} already exists")
370         exit(1)
371
372 log_file = open(os.path.join(args.result_dir, args.log_filename), "a")
373
374 if args.seed >= 0:
375     # torch.backends.cudnn.deterministic = True
376     # torch.backends.cudnn.benchmark = False
377     # torch.use_deterministic_algorithms(True)
378     torch.manual_seed(args.seed)
379     if torch.cuda.is_available():
380         torch.cuda.manual_seed_all(args.seed)
381
382 ######################################################################
383
384
385 def log_string(s):
386     t = time.strftime("%Y%m%d-%H:%M:%S ", time.localtime())
387
388     if log_file is not None:
389         log_file.write(t + s + "\n")
390         log_file.flush()
391
392     print(t + s)
393     sys.stdout.flush()
394
395
396 log_string(f"argv {' '.join(sys.argv)}")
397
398 for n in vars(args):
399     log_string(f"args.{n} {getattr(args, n)}")
400
401
402 ######################################################################
403
404
405 def picoclvr_pruner_horizontal_green(p):
406     return not ("green" in p and ("left" in p or "right" in p))
407
408
409 picoclvr_pruner_train = (
410     picoclvr_pruner_horizontal_green
411     if args.picocvlr_prune_properties in {"train+eval"}
412     else None
413 )
414
415 picoclvr_pruner_eval = (
416     (lambda p: not picoclvr_pruner_horizontal_green(p))
417     if args.picocvlr_prune_properties in {"train+eval", "eval"}
418     else None
419 )
420
421 ######################################################################
422
423 if args.task == "file":
424     assert (
425         args.filetask_train_file is not None and args.filetask_test_file is not None
426     ), "You have to specify the task train and test files"
427     task = tasks.TaskFromFile(
428         args.filetask_train_file,
429         args.filetask_test_file,
430         nb_train_samples=args.nb_train_samples,
431         nb_test_samples=args.nb_test_samples,
432         batch_size=args.batch_size,
433         shuffle=True,
434         device=device,
435     )
436     args.max_percents_of_test_in_train = 0
437
438 elif args.task == "byheart":
439     task = tasks.SandBox(
440         problem=problems.ProblemByHeart(),
441         nb_train_samples=args.nb_train_samples,
442         nb_test_samples=args.nb_test_samples,
443         batch_size=args.batch_size,
444         logger=log_string,
445         device=device,
446     )
447     args.max_percents_of_test_in_train = -1
448
449 elif args.task == "learnop":
450     task = tasks.SandBox(
451         problem=problems.ProblemLearnOperator(),
452         nb_train_samples=args.nb_train_samples,
453         nb_test_samples=args.nb_test_samples,
454         batch_size=args.batch_size,
455         logger=log_string,
456         device=device,
457     )
458
459
460 elif args.task == "guessop":
461     task = tasks.SandBox(
462         problem=problems.ProblemGuessOperator(),
463         nb_train_samples=args.nb_train_samples,
464         nb_test_samples=args.nb_test_samples,
465         batch_size=args.batch_size,
466         logger=log_string,
467         device=device,
468     )
469
470
471 elif args.task == "twotargets":
472     task = tasks.SandBox(
473         problem=problems.ProblemTwoTargets(),
474         nb_train_samples=args.nb_train_samples,
475         nb_test_samples=args.nb_test_samples,
476         batch_size=args.batch_size,
477         logger=log_string,
478         device=device,
479     )
480
481 elif args.task == "memory":
482     task = tasks.SandBox(
483         problem=problems.ProblemMemory(),
484         nb_train_samples=args.nb_train_samples,
485         nb_test_samples=args.nb_test_samples,
486         batch_size=args.batch_size,
487         logger=log_string,
488         device=device,
489     )
490
491 elif args.task == "mixing":
492     task = tasks.SandBox(
493         problem=problems.ProblemMixing(
494             hard=args.mixing_hard, random_start=not args.mixing_deterministic_start
495         ),
496         nb_train_samples=args.nb_train_samples,
497         nb_test_samples=args.nb_test_samples,
498         batch_size=args.batch_size,
499         logger=log_string,
500         device=device,
501     )
502
503 elif args.task == "addition":
504     task = tasks.SandBox(
505         problem=problems.ProblemAddition(),
506         nb_train_samples=args.nb_train_samples,
507         nb_test_samples=args.nb_test_samples,
508         batch_size=args.batch_size,
509         logger=log_string,
510         device=device,
511     )
512
513 elif args.task == "picoclvr":
514     task = tasks.PicoCLVR(
515         nb_train_samples=args.nb_train_samples,
516         nb_test_samples=args.nb_test_samples,
517         batch_size=args.batch_size,
518         height=args.picoclvr_height,
519         width=args.picoclvr_width,
520         nb_colors=args.picoclvr_nb_colors,
521         logger=log_string,
522         device=device,
523         pruner_train=picoclvr_pruner_train,
524         pruner_eval=picoclvr_pruner_eval,
525     )
526
527 elif args.task == "mnist":
528     task = tasks.MNIST(
529         nb_train_samples=args.nb_train_samples,
530         nb_test_samples=args.nb_test_samples,
531         batch_size=args.batch_size,
532         device=device,
533     )
534
535 elif args.task == "maze":
536     task = tasks.Maze(
537         nb_train_samples=args.nb_train_samples,
538         nb_test_samples=args.nb_test_samples,
539         batch_size=args.batch_size,
540         height=args.maze_height,
541         width=args.maze_width,
542         nb_walls=args.maze_nb_walls,
543         device=device,
544     )
545
546 elif args.task == "snake":
547     task = tasks.Snake(
548         nb_train_samples=args.nb_train_samples,
549         nb_test_samples=args.nb_test_samples,
550         batch_size=args.batch_size,
551         height=args.snake_height,
552         width=args.snake_width,
553         nb_colors=args.snake_nb_colors,
554         length=args.snake_length,
555         prompt_length=args.snake_length // 2,
556         device=device,
557     )
558
559 elif args.task == "stack":
560     task = tasks.Stack(
561         nb_train_samples=args.nb_train_samples,
562         nb_test_samples=args.nb_test_samples,
563         batch_size=args.batch_size,
564         logger=log_string,
565         nb_steps=args.stack_nb_steps,
566         nb_stacks=args.stack_nb_stacks,
567         nb_digits=args.stack_nb_digits,
568         fraction_values_for_train=args.stack_fraction_values_for_train,
569         device=device,
570     )
571
572 elif args.task == "expr":
573     task = tasks.Expr(
574         nb_train_samples=args.nb_train_samples,
575         nb_test_samples=args.nb_test_samples,
576         nb_variables=args.expr_nb_variables,
577         sequence_length=args.expr_sequence_length,
578         operand_max=args.expr_operand_max,
579         result_max=args.expr_result_max,
580         batch_size=args.batch_size,
581         device=device,
582     )
583
584 elif args.task == "rpl":
585     task = tasks.RPL(
586         nb_train_samples=args.nb_train_samples,
587         nb_test_samples=args.nb_test_samples,
588         batch_size=args.batch_size,
589         nb_starting_values=args.rpl_nb_starting_values,
590         max_input=args.rpl_max_input,
591         prog_len=args.rpl_prog_len,
592         nb_runs=args.rpl_nb_runs,
593         no_prog=args.rpl_no_prog,
594         logger=log_string,
595         device=device,
596     )
597
598 elif args.task == "grid":
599     task = tasks.Grid(
600         nb_train_samples=args.nb_train_samples,
601         nb_test_samples=args.nb_test_samples,
602         batch_size=args.batch_size,
603         size=args.grid_size,
604         fraction_play=args.grid_fraction_play,
605         logger=log_string,
606         device=device,
607     )
608
609 elif args.task == "qmlp":
610     task = tasks.QMLP(
611         nb_train_samples=args.nb_train_samples,
612         nb_test_samples=args.nb_test_samples,
613         batch_size=args.batch_size,
614         result_dir=args.result_dir,
615         logger=log_string,
616         device=device,
617     )
618
619 elif args.task == "escape":
620     task = tasks.Escape(
621         nb_train_samples=args.nb_train_samples,
622         nb_test_samples=args.nb_test_samples,
623         batch_size=args.batch_size,
624         height=args.escape_height,
625         width=args.escape_width,
626         T=args.escape_T,
627         nb_walls=args.escape_nb_walls,
628         logger=log_string,
629         device=device,
630     )
631
632 else:
633     raise ValueError(f"Unknown task {args.task}")
634
635 ######################################################################
636
637 log_string(f"device {device}")
638
639 vocabulary_size = task.vocabulary_size()
640
641 log_string(f"vocabulary_size {vocabulary_size}")
642
643 ##############################
644
645 model = mygpt.MyGPT(
646     vocabulary_size=vocabulary_size,
647     dim_model=args.dim_model,
648     dim_keys=args.dim_keys,
649     dim_hidden=args.dim_hidden,
650     nb_heads=args.nb_heads,
651     nb_blocks=args.nb_blocks,
652     causal=True,
653     dropout=args.dropout,
654 )
655
656 model.to(device)
657
658 nb_parameters = sum(p.numel() for p in model.parameters())
659 log_string(f"nb_parameters {nb_parameters} ({int(nb_parameters/1e6)}M)")
660
661 ######################################################################
662
663 nb_epochs_finished = 0
664
665 if args.no_checkpoint:
666     log_string(f"not trying to load checkpoint.")
667
668 else:
669     try:
670         checkpoint_name = os.path.join(args.result_dir, args.checkpoint_name)
671         checkpoint = torch.load(checkpoint_name)
672         nb_epochs_finished = checkpoint["nb_epochs_finished"]
673         model.load_state_dict(checkpoint["model_state"])
674         torch.set_rng_state(checkpoint["rng_state"])
675         if torch.cuda.is_available():
676             torch.cuda.set_rng_state(checkpoint["cuda_rng_state"])
677
678         log_string(f"checkpoint loaded with {nb_epochs_finished} epochs finished.")
679
680     except FileNotFoundError:
681         log_string("starting from scratch.")
682
683     except:
684         log_string("error when loading the checkpoint.")
685         exit(1)
686
687 ######################################################################
688
689 if args.task == "expr" and args.expr_input_file is not None:
690     task.produce_results(
691         n_epoch=nb_epochs_finished,
692         model=model,
693         result_dir=args.result_dir,
694         logger=log_string,
695         deterministic_synthesis=args.deterministic_synthesis,
696         input_file=args.expr_input_file,
697     )
698
699     exit(0)
700
701 ######################################################################
702
703 nb_epochs = args.nb_epochs if args.nb_epochs > 0 else nb_epochs_default
704
705 # Compute the entropy of the training tokens
706
707 token_count = 0
708 for input in task.batches(split="train"):
709     token_count += F.one_hot(input, num_classes=task.vocabulary_size()).sum((0, 1))
710 token_probas = token_count / token_count.sum()
711 entropy = -torch.xlogy(token_probas, token_probas).sum()
712 train_set_perplexity = math.exp(entropy)
713
714 ######################################################################
715 # A bit of paranoia never hurts
716
717 if args.max_percents_of_test_in_train >= 0:
718
719     def subsets_as_tuples(batches, cs):
720         s = set()
721         for batch in batches:
722             for x in batch:
723                 s.add(tuple([v.item() for v in x]))
724                 if len(s) == cs:
725                     yield s
726                     s = set()
727         yield s
728
729     nb_test, nb_in_train = 0, 0
730     for test_subset in subsets_as_tuples(task.batches(split="test"), 25000):
731         in_train = set()
732         for train_subset in subsets_as_tuples(task.batches(split="train"), 25000):
733             in_train.update(test_subset.intersection(train_subset))
734         nb_in_train += len(in_train)
735         nb_test += len(test_subset)
736
737     log_string(
738         f"data_check {nb_in_train*100/nb_test:.02f}% ({nb_in_train}/{nb_test}) of test samples are in the train set"
739     )
740
741     assert (
742         nb_in_train <= args.max_percents_of_test_in_train * nb_test / 100
743     ), f"More than {args.max_percents_of_test_in_train}% of test samples are in the train set"
744
745 ##############################
746
747 if args.learning_rate_schedule == "cos":
748     learning_rate_schedule = {}
749     for n_epoch in range(args.nb_epochs):
750         u = n_epoch / args.nb_epochs * math.pi
751         learning_rate_schedule[n_epoch] = args.learning_rate * 0.5 * (1 + math.cos(u))
752 else:
753     u = {
754         int(k): float(v)
755         for k, v in [
756             tuple(x.split(":")) for x in args.learning_rate_schedule.split(",")
757         ]
758     }
759
760     learning_rate_schedule = {}
761     learning_rate = args.learning_rate
762     for n_epoch in range(args.nb_epochs):
763         if n_epoch in u:
764             learning_rate = u[n_epoch]
765         learning_rate_schedule[n_epoch] = learning_rate
766
767 log_string(f"learning_rate_schedule {learning_rate_schedule}")
768
769 ##############################
770
771 nb_samples_seen = 0
772
773 if nb_epochs_finished >= nb_epochs:
774     task.produce_results(
775         n_epoch=nb_epochs_finished,
776         model=model,
777         result_dir=args.result_dir,
778         logger=log_string,
779         deterministic_synthesis=args.deterministic_synthesis,
780     )
781
782 time_pred_result = None
783
784 for n_epoch in range(nb_epochs_finished, nb_epochs):
785     learning_rate = learning_rate_schedule[n_epoch]
786
787     log_string(f"learning_rate {learning_rate}")
788
789     if args.optim == "sgd":
790         optimizer = torch.optim.SGD(model.parameters(), lr=learning_rate)
791     elif args.optim == "adam":
792         optimizer = torch.optim.Adam(model.parameters(), lr=learning_rate)
793     elif args.optim == "adamw":
794         optimizer = torch.optim.AdamW(model.parameters(), lr=learning_rate)
795     else:
796         raise ValueError(f"Unknown optimizer {args.optim}.")
797
798     model.train()
799
800     nb_train_samples, acc_train_loss = 0, 0.0
801
802     for input in task.batches(split="train"):
803         input = input.to(device)
804         output = model(mygpt.BracketedSequence(input)).x
805         loss = F.cross_entropy(output.transpose(1, 2), input)
806         acc_train_loss += loss.item() * input.size(0)
807         nb_train_samples += input.size(0)
808         nb_samples_seen += input.size(0)
809
810         optimizer.zero_grad()
811         loss.backward()
812         optimizer.step()
813
814     with torch.autograd.no_grad():
815         model.eval()
816
817         nb_test_samples, acc_test_loss = 0, 0.0
818
819         for input in task.batches(split="test"):
820             input = input.to(device)
821
822             output = model(mygpt.BracketedSequence(input)).x
823             loss = F.cross_entropy(output.transpose(1, 2), input)
824             acc_test_loss += loss.item() * input.size(0)
825             nb_test_samples += input.size(0)
826
827         train_perplexity = math.exp(min(100, acc_train_loss / nb_train_samples))
828         test_perplexity = math.exp(min(100, acc_test_loss / nb_test_samples))
829
830         log_string(
831             f"perplexity {n_epoch} train_set {train_set_perplexity} train_prediction {train_perplexity} test_prediction {test_perplexity}"
832         )
833
834         task.produce_results(
835             n_epoch=n_epoch,
836             model=model,
837             result_dir=args.result_dir,
838             logger=log_string,
839             deterministic_synthesis=args.deterministic_synthesis,
840         )
841
842         time_current_result = datetime.datetime.now()
843         if time_pred_result is not None:
844             log_string(
845                 f"next_result {time_current_result + (time_current_result - time_pred_result)}"
846             )
847         time_pred_result = time_current_result
848
849     checkpoint = {
850         "nb_epochs_finished": n_epoch + 1,
851         "model_state": model.state_dict(),
852         "rng_state": torch.get_rng_state(),
853     }
854
855     if torch.cuda.is_available():
856         checkpoint["cuda_rng_state"] = torch.cuda.get_rng_state()
857
858     checkpoint_name = os.path.join(args.result_dir, args.checkpoint_name)
859     torch.save(checkpoint, checkpoint_name)
860     log_string(f"saved checkpoint {checkpoint_name}")
861
862 ######################################################################