-
Notifications
You must be signed in to change notification settings - Fork 13
/
imagenet_finetune_tokencut.py
577 lines (489 loc) · 25.2 KB
/
imagenet_finetune_tokencut.py
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
import argparse
import os
import random
import shutil
import time
import warnings
import torch
import torch.nn as nn
import torch.nn.parallel
import torch.backends.cudnn as cudnn
import torch.distributed as dist
import torch.optim
import torch.multiprocessing as mp
import torch.utils.data
import torch.utils.data.distributed
import torchvision.transforms as transforms
import torchvision.datasets as datasets
import torchvision.models as models
from tokencut_dataset import SegmentationDataset, VAL_PARTITION, TRAIN_PARTITION
# Uncomment the expected model below
# ViT
from ViT.ViT import vit_base_patch16_224 as vit
# from ViT.ViT import vit_large_patch16_224 as vit
# ViT-AugReg
# from ViT.ViT_new import vit_small_patch16_224 as vit
# from ViT.ViT_new import vit_base_patch16_224 as vit
# from ViT.ViT_new import vit_large_patch16_224 as vit
# DeiT
# from ViT.ViT import deit_base_patch16_224 as vit
# from ViT.ViT import deit_small_patch16_224 as vit
from ViT.explainer import generate_relevance, get_image_with_relevance
import torchvision
import cv2
from torch.utils.tensorboard import SummaryWriter
import json
model_names = sorted(name for name in models.__dict__
if name.islower() and not name.startswith("__")
and callable(models.__dict__[name]))
model_names.append("vit")
parser = argparse.ArgumentParser(description='PyTorch ImageNet Training')
parser.add_argument('--data', metavar='DATA',
help='path to dataset')
parser.add_argument('--seg_data', metavar='SEG_DATA',
help='path to segmentation dataset')
parser.add_argument('-j', '--workers', default=4, type=int, metavar='N',
help='number of data loading workers (default: 4)')
parser.add_argument('--epochs', default=150, type=int, metavar='N',
help='number of total epochs to run')
parser.add_argument('--start-epoch', default=0, type=int, metavar='N',
help='manual epoch number (useful on restarts)')
parser.add_argument('-b', '--batch-size', default=10, type=int,
metavar='N',
help='mini-batch size (default: 256), this is the total '
'batch size of all GPUs on the current node when '
'using Data Parallel or Distributed Data Parallel')
parser.add_argument('--lr', '--learning-rate', default=3e-6, type=float,
metavar='LR', help='initial learning rate', dest='lr')
parser.add_argument('--momentum', default=0.9, type=float, metavar='M',
help='momentum')
parser.add_argument('--wd', '--weight-decay', default=1e-4, type=float,
metavar='W', help='weight decay (default: 1e-4)',
dest='weight_decay')
parser.add_argument('-p', '--print-freq', default=10, type=int,
metavar='N', help='print frequency (default: 10)')
parser.add_argument('--resume', default='', type=str, metavar='PATH',
help='path to latest checkpoint (default: none)')
parser.add_argument('-e', '--evaluate', dest='evaluate', action='store_true',
help='evaluate model on validation set')
parser.add_argument('--pretrained', dest='pretrained', action='store_true',
help='use pre-trained model')
parser.add_argument('--world-size', default=-1, type=int,
help='number of nodes for distributed training')
parser.add_argument('--rank', default=-1, type=int,
help='node rank for distributed training')
parser.add_argument('--dist-url', default='tcp://224.66.41.62:23456', type=str,
help='url used to set up distributed training')
parser.add_argument('--dist-backend', default='nccl', type=str,
help='distributed backend')
parser.add_argument('--seed', default=None, type=int,
help='seed for initializing training. ')
parser.add_argument('--gpu', default=None, type=int,
help='GPU id to use.')
parser.add_argument('--save_interval', default=20, type=int,
help='interval to save segmentation results.')
parser.add_argument('--num_samples', default=3, type=int,
help='number of samples per class for training')
parser.add_argument('--multiprocessing-distributed', action='store_true',
help='Use multi-processing distributed training to launch '
'N processes per node, which has N GPUs. This is the '
'fastest way to use PyTorch for either single node or '
'multi node data parallel training')
parser.add_argument('--lambda_seg', default=0.1, type=float,
help='influence of segmentation loss.')
parser.add_argument('--lambda_acc', default=1, type=float,
help='influence of accuracy loss.')
parser.add_argument('--experiment_folder', default=None, type=str,
help='path to folder to use for experiment.')
parser.add_argument('--dilation', default=0, type=float,
help='Use dilation on the segmentation maps.')
parser.add_argument('--lambda_background', default=1, type=float,
help='coefficient of loss for segmentation background.')
parser.add_argument('--lambda_foreground', default=0.3, type=float,
help='coefficient of loss for segmentation foreground.')
parser.add_argument('--num_classes', default=500, type=int,
help='coefficient of loss for segmentation foreground.')
parser.add_argument('--temperature', default=1, type=float,
help='temperature for softmax (mostly for DeiT).')
best_loss = float('inf')
def main():
args = parser.parse_args()
if args.experiment_folder is None:
args.experiment_folder = f'experiment/' \
f'lr_{args.lr}_seg_{args.lambda_seg}_acc_{args.lambda_acc}' \
f'_bckg_{args.lambda_background}_fgd_{args.lambda_foreground}'
if args.temperature != 1:
args.experiment_folder = args.experiment_folder + f'_tempera_{args.temperature}'
if args.batch_size != 8:
args.experiment_folder = args.experiment_folder + f'_bs_{args.batch_size}'
if args.num_classes != 500:
args.experiment_folder = args.experiment_folder + f'_num_classes_{args.num_classes}'
if args.num_samples != 3:
args.experiment_folder = args.experiment_folder + f'_num_samples_{args.num_samples}'
if args.epochs != 150:
args.experiment_folder = args.experiment_folder + f'_num_epochs_{args.epochs}'
if os.path.exists(args.experiment_folder):
raise Exception(f"Experiment path {args.experiment_folder} already exists!")
os.mkdir(args.experiment_folder)
os.mkdir(f'{args.experiment_folder}/train_samples')
os.mkdir(f'{args.experiment_folder}/val_samples')
with open(f'{args.experiment_folder}/commandline_args.txt', 'w') as f:
json.dump(args.__dict__, f, indent=2)
if args.seed is not None:
random.seed(args.seed)
torch.manual_seed(args.seed)
cudnn.deterministic = True
warnings.warn('You have chosen to seed training. '
'This will turn on the CUDNN deterministic setting, '
'which can slow down your training considerably! '
'You may see unexpected behavior when restarting '
'from checkpoints.')
if args.gpu is not None:
warnings.warn('You have chosen a specific GPU. This will completely '
'disable data parallelism.')
if args.dist_url == "env://" and args.world_size == -1:
args.world_size = int(os.environ["WORLD_SIZE"])
args.distributed = args.world_size > 1 or args.multiprocessing_distributed
ngpus_per_node = torch.cuda.device_count()
if args.multiprocessing_distributed:
# Since we have ngpus_per_node processes per node, the total world_size
# needs to be adjusted accordingly
args.world_size = ngpus_per_node * args.world_size
# Use torch.multiprocessing.spawn to launch distributed processes: the
# main_worker process function
mp.spawn(main_worker, nprocs=ngpus_per_node, args=(ngpus_per_node, args))
else:
# Simply call main_worker function
main_worker(args.gpu, ngpus_per_node, args)
def main_worker(gpu, ngpus_per_node, args):
global best_loss
args.gpu = gpu
if args.gpu is not None:
print("Use GPU: {} for training".format(args.gpu))
if args.distributed:
if args.dist_url == "env://" and args.rank == -1:
args.rank = int(os.environ["RANK"])
if args.multiprocessing_distributed:
# For multiprocessing distributed training, rank needs to be the
# global rank among all the processes
args.rank = args.rank * ngpus_per_node + gpu
dist.init_process_group(backend=args.dist_backend, init_method=args.dist_url,
world_size=args.world_size, rank=args.rank)
# create model
print("=> creating model")
model = vit(pretrained=True).cuda()
model.train()
print("done")
if not torch.cuda.is_available():
print('using CPU, this will be slow')
elif args.distributed:
# For multiprocessing distributed, DistributedDataParallel constructor
# should always set the single device scope, otherwise,
# DistributedDataParallel will use all available devices.
if args.gpu is not None:
torch.cuda.set_device(args.gpu)
model.cuda(args.gpu)
# When using a single GPU per process and per
# DistributedDataParallel, we need to divide the batch size
# ourselves based on the total number of GPUs we have
args.batch_size = int(args.batch_size / ngpus_per_node)
args.workers = int((args.workers + ngpus_per_node - 1) / ngpus_per_node)
model = torch.nn.parallel.DistributedDataParallel(model, device_ids=[args.gpu])
else:
model.cuda()
# DistributedDataParallel will divide and allocate batch_size to all
# available GPUs if device_ids are not set
model = torch.nn.parallel.DistributedDataParallel(model)
elif args.gpu is not None:
torch.cuda.set_device(args.gpu)
model = model.cuda(args.gpu)
else:
# DataParallel will divide and allocate batch_size to all available GPUs
print("start")
model = torch.nn.DataParallel(model).cuda()
# define loss function (criterion) and optimizer
criterion = nn.CrossEntropyLoss().cuda(args.gpu)
optimizer = torch.optim.AdamW(model.parameters(), args.lr, weight_decay=args.weight_decay)
# optionally resume from a checkpoint
if args.resume:
if os.path.isfile(args.resume):
print("=> loading checkpoint '{}'".format(args.resume))
if args.gpu is None:
checkpoint = torch.load(args.resume)
else:
# Map model to be loaded to specified single gpu.
loc = 'cuda:{}'.format(args.gpu)
checkpoint = torch.load(args.resume, map_location=loc)
args.start_epoch = checkpoint['epoch']
best_loss = checkpoint['best_loss']
if args.gpu is not None:
# best_loss may be from a checkpoint from a different GPU
best_loss = best_loss.to(args.gpu)
model.load_state_dict(checkpoint['state_dict'])
optimizer.load_state_dict(checkpoint['optimizer'])
print("=> loaded checkpoint '{}' (epoch {})"
.format(args.resume, checkpoint['epoch']))
else:
print("=> no checkpoint found at '{}'".format(args.resume))
cudnn.benchmark = True
train_dataset = SegmentationDataset(args.seg_data, args.data, partition=TRAIN_PARTITION, train_classes=args.num_classes,
num_samples=args.num_samples)
if args.distributed:
train_sampler = torch.utils.data.distributed.DistributedSampler(train_dataset)
else:
train_sampler = None
train_loader = torch.utils.data.DataLoader(
train_dataset, batch_size=args.batch_size, shuffle=(train_sampler is None),
num_workers=args.workers, pin_memory=True, sampler=train_sampler)
val_dataset = SegmentationDataset(args.seg_data, args.data, partition=VAL_PARTITION, train_classes=args.num_classes,
num_samples=1)
val_loader = torch.utils.data.DataLoader(
val_dataset, batch_size=10, shuffle=False,
num_workers=args.workers, pin_memory=True)
if args.evaluate:
validate(val_loader, model, criterion, 0, args)
return
for epoch in range(args.start_epoch, args.epochs):
if args.distributed:
train_sampler.set_epoch(epoch)
adjust_learning_rate(optimizer, epoch, args)
log_dir = os.path.join(args.experiment_folder, 'logs')
logger = SummaryWriter(log_dir=log_dir)
args.logger = logger
# train for one epoch
train(train_loader, model, criterion, optimizer, epoch, args)
# evaluate on validation set
loss1 = validate(val_loader, model, criterion, epoch, args)
# remember best acc@1 and save checkpoint
is_best = loss1 <= best_loss
best_loss = min(loss1, best_loss)
if not args.multiprocessing_distributed or (args.multiprocessing_distributed
and args.rank % ngpus_per_node == 0):
save_checkpoint({
'epoch': epoch + 1,
'state_dict': model.state_dict(),
'best_loss': best_loss,
'optimizer' : optimizer.state_dict(),
}, is_best, folder=args.experiment_folder)
def train(train_loader, model, criterion, optimizer, epoch, args):
mse_criterion = torch.nn.MSELoss(reduction='mean')
losses = AverageMeter('Loss', ':.4e')
top1 = AverageMeter('Acc@1', ':6.2f')
top5 = AverageMeter('Acc@5', ':6.2f')
orig_top1 = AverageMeter('Acc@1_orig', ':6.2f')
orig_top5 = AverageMeter('Acc@5_orig', ':6.2f')
progress = ProgressMeter(
len(train_loader),
# [batch_time, data_time, losses, top1, top5, orig_top1, orig_top5],
[losses, top1, top5, orig_top1, orig_top5],
prefix="Epoch: [{}]".format(epoch))
orig_model = vit(pretrained=True).cuda()
orig_model.eval()
# switch to train mode
model.train()
end = time.time()
for i, (seg_map, image_ten, class_name) in enumerate(train_loader):
if torch.cuda.is_available():
image_ten = image_ten.cuda(args.gpu, non_blocking=True)
seg_map = seg_map.cuda(args.gpu, non_blocking=True)
class_name = class_name.cuda(args.gpu, non_blocking=True)
# compute output
# segmentation loss
relevance = generate_relevance(model, image_ten, index=class_name)
reverse_seg_map = seg_map.clone()
reverse_seg_map[reverse_seg_map == 1] = -1
reverse_seg_map[reverse_seg_map == 0] = 1
reverse_seg_map[reverse_seg_map == -1] = 0
background_loss = mse_criterion(relevance * reverse_seg_map, torch.zeros_like(relevance))
foreground_loss = mse_criterion(relevance * seg_map, seg_map)
segmentation_loss = args.lambda_background * background_loss
segmentation_loss += args.lambda_foreground * foreground_loss
# classification loss
output = model(image_ten)
with torch.no_grad():
output_orig = orig_model(image_ten)
_, pred = output.topk(1, 1, True, True)
pred = pred.flatten()
if args.temperature != 1:
output = output / args.temperature
classification_loss = criterion(output, pred)
loss = args.lambda_seg * segmentation_loss + args.lambda_acc * classification_loss
# debugging output
if i % args.save_interval == 0:
orig_relevance = generate_relevance(orig_model, image_ten, index=class_name)
for j in range(image_ten.shape[0]):
image = get_image_with_relevance(image_ten[j], torch.ones_like(image_ten[j]))
new_vis = get_image_with_relevance(image_ten[j], relevance[j])
old_vis = get_image_with_relevance(image_ten[j], orig_relevance[j])
gt = get_image_with_relevance(image_ten[j], seg_map[j])
h_img = cv2.hconcat([image, gt, old_vis, new_vis])
cv2.imwrite(f'{args.experiment_folder}/train_samples/res_{i}_{j}.jpg', h_img)
# measure accuracy and record loss
acc1, acc5 = accuracy(output, class_name, topk=(1, 5))
losses.update(loss.item(), image_ten.size(0))
top1.update(acc1[0], image_ten.size(0))
top5.update(acc5[0], image_ten.size(0))
# metrics for original vit
acc1_orig, acc5_orig = accuracy(output_orig, class_name, topk=(1, 5))
orig_top1.update(acc1_orig[0], image_ten.size(0))
orig_top5.update(acc5_orig[0], image_ten.size(0))
# compute gradient and do SGD step
optimizer.zero_grad()
loss.backward()
optimizer.step()
if i % args.print_freq == 0:
progress.display(i)
args.logger.add_scalar('{}/{}'.format('train', 'segmentation_loss'), segmentation_loss,
epoch*len(train_loader)+i)
args.logger.add_scalar('{}/{}'.format('train', 'classification_loss'), classification_loss,
epoch * len(train_loader) + i)
args.logger.add_scalar('{}/{}'.format('train', 'orig_top1'), acc1_orig,
epoch * len(train_loader) + i)
args.logger.add_scalar('{}/{}'.format('train', 'top1'), acc1,
epoch * len(train_loader) + i)
args.logger.add_scalar('{}/{}'.format('train', 'orig_top5'), acc5_orig,
epoch * len(train_loader) + i)
args.logger.add_scalar('{}/{}'.format('train', 'top5'), acc5,
epoch * len(train_loader) + i)
args.logger.add_scalar('{}/{}'.format('train', 'tot_loss'), loss,
epoch * len(train_loader) + i)
def validate(val_loader, model, criterion, epoch, args):
mse_criterion = torch.nn.MSELoss(reduction='mean')
losses = AverageMeter('Loss', ':.4e')
top1 = AverageMeter('Acc@1', ':6.2f')
top5 = AverageMeter('Acc@5', ':6.2f')
orig_top1 = AverageMeter('Acc@1_orig', ':6.2f')
orig_top5 = AverageMeter('Acc@5_orig', ':6.2f')
progress = ProgressMeter(
len(val_loader),
[losses, top1, top5, orig_top1, orig_top5],
prefix="Epoch: [{}]".format(val_loader))
# switch to evaluate mode
model.eval()
orig_model = vit(pretrained=True).cuda()
orig_model.eval()
with torch.no_grad():
end = time.time()
for i, (seg_map, image_ten, class_name) in enumerate(val_loader):
if args.gpu is not None:
image_ten = image_ten.cuda(args.gpu, non_blocking=True)
if torch.cuda.is_available():
seg_map = seg_map.cuda(args.gpu, non_blocking=True)
class_name = class_name.cuda(args.gpu, non_blocking=True)
# segmentation loss
with torch.enable_grad():
relevance = generate_relevance(model, image_ten, index=class_name)
reverse_seg_map = seg_map.clone()
reverse_seg_map[reverse_seg_map == 1] = -1
reverse_seg_map[reverse_seg_map == 0] = 1
reverse_seg_map[reverse_seg_map == -1] = 0
background_loss = mse_criterion(relevance * reverse_seg_map, torch.zeros_like(relevance))
foreground_loss = mse_criterion(relevance * seg_map, seg_map)
segmentation_loss = args.lambda_background * background_loss
segmentation_loss += args.lambda_foreground * foreground_loss
# classification loss
with torch.no_grad():
output = model(image_ten)
output_orig = orig_model(image_ten)
_, pred = output.topk(1, 1, True, True)
pred = pred.flatten()
if args.temperature != 1:
output = output / args.temperature
classification_loss = criterion(output, pred)
loss = args.lambda_seg * segmentation_loss + args.lambda_acc * classification_loss
# save results
if i % args.save_interval == 0:
with torch.enable_grad():
orig_relevance = generate_relevance(orig_model, image_ten, index=class_name)
for j in range(image_ten.shape[0]):
image = get_image_with_relevance(image_ten[j], torch.ones_like(image_ten[j]))
new_vis = get_image_with_relevance(image_ten[j], relevance[j])
old_vis = get_image_with_relevance(image_ten[j], orig_relevance[j])
gt = get_image_with_relevance(image_ten[j], seg_map[j])
h_img = cv2.hconcat([image, gt, old_vis, new_vis])
cv2.imwrite(f'{args.experiment_folder}/val_samples/res_{i}_{j}.jpg', h_img)
# measure accuracy and record loss
acc1, acc5 = accuracy(output, class_name, topk=(1, 5))
losses.update(loss.item(), image_ten.size(0))
top1.update(acc1[0], image_ten.size(0))
top5.update(acc5[0], image_ten.size(0))
# metrics for original vit
acc1_orig, acc5_orig = accuracy(output_orig, class_name, topk=(1, 5))
orig_top1.update(acc1_orig[0], image_ten.size(0))
orig_top5.update(acc5_orig[0], image_ten.size(0))
if i % args.print_freq == 0:
progress.display(i)
args.logger.add_scalar('{}/{}'.format('val', 'segmentation_loss'), segmentation_loss,
epoch * len(val_loader) + i)
args.logger.add_scalar('{}/{}'.format('val', 'classification_loss'), classification_loss,
epoch * len(val_loader) + i)
args.logger.add_scalar('{}/{}'.format('val', 'orig_top1'), acc1_orig,
epoch * len(val_loader) + i)
args.logger.add_scalar('{}/{}'.format('val', 'top1'), acc1,
epoch * len(val_loader) + i)
args.logger.add_scalar('{}/{}'.format('val', 'orig_top5'), acc5_orig,
epoch * len(val_loader) + i)
args.logger.add_scalar('{}/{}'.format('val', 'top5'), acc5,
epoch * len(val_loader) + i)
args.logger.add_scalar('{}/{}'.format('val', 'tot_loss'), loss,
epoch * len(val_loader) + i)
# TODO: this should also be done with the ProgressMeter
print(' * Acc@1 {top1.avg:.3f} Acc@5 {top5.avg:.3f}'
.format(top1=top1, top5=top5))
return losses.avg
def save_checkpoint(state, is_best, folder, filename='checkpoint.pth.tar'):
torch.save(state, f'{folder}/{filename}')
if is_best:
shutil.copyfile(f'{folder}/{filename}', f'{folder}/model_best.pth.tar')
class AverageMeter(object):
"""Computes and stores the average and current value"""
def __init__(self, name, fmt=':f'):
self.name = name
self.fmt = fmt
self.reset()
def reset(self):
self.val = 0
self.avg = 0
self.sum = 0
self.count = 0
def update(self, val, n=1):
self.val = val
self.sum += val * n
self.count += n
self.avg = self.sum / self.count
def __str__(self):
fmtstr = '{name} {val' + self.fmt + '} ({avg' + self.fmt + '})'
return fmtstr.format(**self.__dict__)
class ProgressMeter(object):
def __init__(self, num_batches, meters, prefix=""):
self.batch_fmtstr = self._get_batch_fmtstr(num_batches)
self.meters = meters
self.prefix = prefix
def display(self, batch):
entries = [self.prefix + self.batch_fmtstr.format(batch)]
entries += [str(meter) for meter in self.meters]
print('\t'.join(entries))
def _get_batch_fmtstr(self, num_batches):
num_digits = len(str(num_batches // 1))
fmt = '{:' + str(num_digits) + 'd}'
return '[' + fmt + '/' + fmt.format(num_batches) + ']'
def adjust_learning_rate(optimizer, epoch, args):
"""Sets the learning rate to the initial LR decayed by 10 every 30 epochs"""
lr = args.lr * (0.85 ** (epoch // 2))
for param_group in optimizer.param_groups:
param_group['lr'] = lr
def accuracy(output, target, topk=(1,)):
"""Computes the accuracy over the k top predictions for the specified values of k"""
with torch.no_grad():
maxk = max(topk)
batch_size = target.size(0)
_, pred = output.topk(maxk, 1, True, True)
pred = pred.t()
correct = pred.eq(target.view(1, -1).expand_as(pred))
res = []
for k in topk:
correct_k = correct[:k].reshape(-1).float().sum(0, keepdim=True)
res.append(correct_k.mul_(100.0 / batch_size))
return res
if __name__ == '__main__':
main()