def train(train_source_iter: ForeverDataIterator,
train_target_iter: ForeverDataIterator, model: ImageClassifier,
domain_adv: DomainAdversarialLoss, optimizer: SGD,
lr_scheduler: StepwiseLR, epoch: int, args: argparse.Namespace):
batch_time = AverageMeter('Time', ':5.2f')
data_time = AverageMeter('Data', ':5.2f')
losses = AverageMeter('Loss', ':6.2f')
cls_accs = AverageMeter('Cls Acc', ':3.1f')
domain_accs = AverageMeter('Domain Acc', ':3.1f')
progress = ProgressMeter(
args.iters_per_epoch,
[batch_time, data_time, losses, cls_accs, domain_accs],
prefix="Epoch: [{}]".format(epoch))
# switch to train mode
model.train()
domain_adv.train()
end = time.time()
for i in range(args.iters_per_epoch):
lr_scheduler.step()
# measure data loading time
data_time.update(time.time() - end)
x_s, labels_s = next(train_source_iter)
x_t, _ = next(train_target_iter)
x_s = x_s.to(device)
x_t = x_t.to(device)
labels_s = labels_s.to(device)
# compute output
x = torch.cat((x_s, x_t), dim=0)
y, f = model(x)
y_s, y_t = y.chunk(2, dim=0)
f_s, f_t = f.chunk(2, dim=0)
cls_loss = F.cross_entropy(y_s, labels_s)
transfer_loss = domain_adv(f_s, f_t)
domain_acc = domain_adv.domain_discriminator_accuracy
loss = cls_loss + transfer_loss * args.trade_off
cls_acc = accuracy(y_s, labels_s)[0]
losses.update(loss.item(), x_s.size(0))
cls_accs.update(cls_acc.item(), x_s.size(0))
domain_accs.update(domain_acc.item(), x_s.size(0))
# compute gradient and do SGD step
optimizer.zero_grad()
loss.backward()
optimizer.step()
# measure elapsed time
batch_time.update(time.time() - end)
end = time.time()
if i % args.print_freq == 0:
progress.display(i)
def train_ssl(inferred_dataloader: DataLoader, model: ImageClassifier,
optimizer: SGD, lr_scheduler: StepwiseLR, epoch: int,
args: argparse.Namespace):
batch_time = AverageMeter('Time', ':6.3f')
losses = AverageMeter('Loss', ':.4e')
top1 = AverageMeter('Acc@1', ':6.2f')
top5 = AverageMeter('Acc@5', ':6.2f')
progress = ProgressMeter(len(inferred_dataloader),
[batch_time, losses, top1, top5],
prefix="Epoch: [{}]".format(epoch))
# switch to train mode
model.train()
end = time.time()
for i, (x, labels) in enumerate(inferred_dataloader):
lr_scheduler.step()
x = x.to(device)
labels = labels.to(device)
# compute output
output, _ = model(x)
loss = F.cross_entropy(output, labels)
# measure accuracy and record loss
acc1, acc5 = accuracy(output, labels, topk=(1, 5))
losses.update(loss.item(), x.size(0))
top1.update(acc1[0], x.size(0))
top5.update(acc5[0], x.size(0))
# compute gradient and do SGD step
optimizer.zero_grad()
loss.backward()
optimizer.step()
# measure elapsed time
batch_time.update(time.time() - end)
end = time.time()
if i % args.print_freq == 0:
progress.display(i)
