def _train(model, optimizer, scheduler, checkpointer, epochs, train_loader,
test_loader, stat_tracker, log_dir, device):
'''
Training loop to train classifiers on top of an encoder with fixed weights.
-- e.g., use this for eval or running on new data
'''
# If mixed precision is on, will add the necessary hooks into the model and
# optimizer for half precision conversions
model, optimizer = mixed_precision.initialize(model, optimizer)
# ...
time_start = time.time()
total_updates = 0
next_epoch, total_updates = checkpointer.get_current_position(
classifier=True)
for epoch in range(next_epoch, epochs):
epoch_updates = 0
epoch_stats = AverageMeterSet()
for _, ((images1, images2), labels) in enumerate(train_loader):
# get data and info about this minibatch
images1 = images1.to(device)
images2 = images2.to(device)
labels = labels.to(device)
# run forward pass through model and collect activations
res_dict = model(x1=images1, x2=images2, class_only=True)
lgt_glb_mlp, lgt_glb_lin = res_dict['class']
# compute total loss for optimization
loss = (loss_xent(lgt_glb_mlp, labels) +
loss_xent(lgt_glb_lin, labels))
# do optimizer step for encoder
optimizer.zero_grad()
mixed_precision.backward(
loss, optimizer) # special mixed precision stuff
optimizer.step()
# record loss and accuracy on minibatch
epoch_stats.update('loss', loss.item(), n=1)
update_train_accuracies(epoch_stats, labels, lgt_glb_mlp,
lgt_glb_lin)
# shortcut diagnostics to deal with long epochs
total_updates += 1
epoch_updates += 1
if (total_updates % 100) == 0:
time_stop = time.time()
spu = (time_stop - time_start) / 100.
print(
'Epoch {0:d}, {1:d} updates -- {2:.4f} sec/update'.format(
epoch, epoch_updates, spu))
time_start = time.time()
# step learning rate scheduler
scheduler.step(epoch)
# record diagnostics
test_model(model, test_loader, device, epoch_stats, max_evals=500000)
epoch_str = epoch_stats.pretty_string(ignore=model.tasks)
diag_str = '{0:d}: {1:s}'.format(epoch, epoch_str)
print(diag_str)
sys.stdout.flush()
stat_tracker.record_stats(epoch_stats.averages(epoch, prefix='eval/'))
checkpointer.update(epoch + 1, total_updates, classifier=True)
def _train(model, optim_inf, scheduler_inf, checkpointer, epochs, train_loader,
test_loader, stat_tracker, log_dir, device, args):
'''
Training loop for optimizing encoder
'''
# If mixed precision is on, will add the necessary hooks into the model
# and optimizer for half() conversions
model, optim_inf = mixed_precision.initialize(model, optim_inf)
optim_raw = mixed_precision.get_optimizer(optim_inf)
# get target LR for LR warmup -- assume same LR for all param groups
for pg in optim_raw.param_groups:
lr_real = pg['lr']
# IDK, maybe this helps?
# but it makes the training slow
# torch.cuda.empty_cache()
# prepare checkpoint and stats accumulator
next_epoch, total_updates = checkpointer.get_current_position()
fast_stats = AverageMeterSet()
# run main training loop
for epoch in range(next_epoch, epochs):
epoch_stats = AverageMeterSet()
epoch_updates = 0
time_start = time.time()
for _, ((images1, images2), labels) in enumerate(train_loader):
# get data and info about this minibatch
labels = torch.cat([labels, labels]).to(device)
images1 = images1.to(device)
images2 = images2.to(device)
# run forward pass through model to get global and local features
res_dict = model(args, x1=images1, x2=images2, class_only=False)
lgt_glb_mlp, lgt_glb_lin = res_dict['class']
# compute costs for all self-supervised tasks
loss_g2l = (res_dict['g2l_1t5'] + res_dict['g2l_1t7'] +
res_dict['g2l_5t5'])
loss_inf = loss_g2l + res_dict['lgt_reg']
# compute loss for online evaluation classifiers
loss_cls = (loss_xent(lgt_glb_mlp, labels) +
loss_xent(lgt_glb_lin, labels))
# do hacky learning rate warmup -- we stop when LR hits lr_real
if (total_updates < 500):
lr_scale = min(1., float(total_updates + 1) / 500.)
for pg in optim_raw.param_groups:
pg['lr'] = lr_scale * lr_real
# reset gradient accumlators and do backprop
loss_opt = loss_inf + loss_cls
optim_inf.zero_grad()
mixed_precision.backward(
loss_opt, optim_inf) # backwards with fp32/fp16 awareness
if args.grad_clip_value and (total_updates >= 500):
torch.nn.utils.clip_grad_value_(model.parameters(),
args.grad_clip_value)
optim_inf.step()
# record loss and accuracy on minibatch
epoch_stats.update_dict(
{
'loss_inf': loss_inf.detach().item(),
'loss_cls': loss_cls.detach().item(),
'loss_g2l': loss_g2l.detach().item(),
'lgt_reg': res_dict['lgt_reg'].detach().item(),
'loss_g2l_1t5': res_dict['g2l_1t5'].detach().item(),
'loss_g2l_1t7': res_dict['g2l_1t7'].detach().item(),
'loss_g2l_5t5': res_dict['g2l_5t5'].detach().item()
},
n=1)
update_train_accuracies(epoch_stats, labels, lgt_glb_mlp,
lgt_glb_lin)
# shortcut diagnostics to deal with long epochs
total_updates += 1
epoch_updates += 1
# this command makes the training slow
# torch.cuda.empty_cache()
if (total_updates % 100) == 0:
# IDK, maybe this helps?
time_stop = time.time()
spu = (time_stop - time_start) / 100.
print(
'Epoch {0:d}, {1:d} updates -- {2:.4f} sec/update'.format(
epoch, epoch_updates, spu))
time_start = time.time()
if (total_updates % 500) == 0:
# record diagnostics
eval_start = time.time()
fast_stats = AverageMeterSet()
test_model(args,
model,
test_loader,
device,
fast_stats,
max_evals=100000)
stat_tracker.record_stats(
fast_stats.averages(total_updates, prefix='fast/'))
eval_time = time.time() - eval_start
stat_str = fast_stats.pretty_string(ignore=model.tasks)
stat_str = '-- {0:d} updates, eval_time {1:.2f}: {2:s}'.format(
total_updates, eval_time, stat_str)
print(stat_str)
# update learning rate
scheduler_inf.step(epoch)
test_model(args,
model,
test_loader,
device,
epoch_stats,
max_evals=500000)
epoch_str = epoch_stats.pretty_string(ignore=model.tasks)
diag_str = '{0:d}: {1:s}'.format(epoch, epoch_str)
print(diag_str)
sys.stdout.flush()
stat_tracker.record_stats(epoch_stats.averages(epoch, prefix='costs/'))
checkpointer.update(epoch + 1, total_updates)
def _train(model,
optim_inf,
scheduler_inf,
checkpointer,
epochs,
train_loader,
test_loader,
stat_tracker,
log_dir,
device,
decoder_training=False):
'''
Training loop for optimizing encoder
'''
# If mixed precision is on, will add the necessary hooks into the model
# and optimizer for half() conversions
model, optim_inf = mixed_precision.initialize(model, optim_inf)
optim_raw = mixed_precision.get_optimizer(optim_inf)
test = test_decoder_model if model.decoder_training else test_model # Nawid - This chooses which method of testing to use
# get target LR for LR warmup -- assume same LR for all param groups
for pg in optim_raw.param_groups:
lr_real = pg['lr']
# IDK, maybe this helps?
torch.cuda.empty_cache()
# prepare checkpoint and stats accumulator
next_epoch, total_updates = checkpointer.get_current_position()
fast_stats = AverageMeterSet()
# run main training loop
for epoch in range(next_epoch, epochs):
epoch_stats = AverageMeterSet()
epoch_updates = 0
time_start = time.time()
for _, ((images1, images2), labels) in enumerate(
train_loader): # Nawid - obtains the images and the labels
# get data and info about this minibatch
labels = torch.cat([labels, labels]).to(device)
images1 = images1.to(device)
images2 = images2.to(device)
# run forward pass through model to get global and local features
res_dict = model(x1=images1, x2=images2, class_only=False)
# compute costs for all self-supervised tasks
loss_g2l = (
res_dict['g2l_1t5'] + res_dict['g2l_1t7'] + res_dict['g2l_5t5']
) # Nawid - loss for the global to local features predictions
loss_inf = loss_g2l + res_dict['lgt_reg']
if model.decoder_training:
image_reconstructions = res_dict['decoder_output']
target_images = torch.cat(
[images1, images2]
) # Nawid - Concatenate both batches along the dimension of number of training examples
auxiliary_loss = loss_MSE(image_reconstructions, target_images)
epoch_stats.update_dict(
{'loss_decoder': auxiliary_loss.item()}, n=1)
else:
# compute loss for online evaluation classifiers
lgt_glb_mlp, lgt_glb_lin = res_dict['class']
auxiliary_loss = (
loss_xent(lgt_glb_mlp, labels)
+ # Nawid - Loss for the classifier terms
loss_xent(lgt_glb_lin, labels))
epoch_stats.update_dict({'loss_cls': auxiliary_loss.item()},
n=1)
update_train_accuracies(epoch_stats, labels, lgt_glb_mlp,
lgt_glb_lin)
# do hacky learning rate warmup -- we stop when LR hits lr_real
if (total_updates < 500):
lr_scale = min(1., float(total_updates + 1) / 500.)
for pg in optim_raw.param_groups:
pg['lr'] = lr_scale * lr_real
# reset gradient accumlators and do backprop
loss_opt = auxiliary_loss #+loss_inf # Nawid - Total loss is the loss from the global to local prediction as well as the loss from the classifier predictions
optim_inf.zero_grad()
mixed_precision.backward(
loss_opt, optim_inf) # backwards with fp32/fp16 awareness
optim_inf.step()
# record loss and accuracy on minibatch
epoch_stats.update_dict(
{ # Nawid - Changed the update so that the auxillary loss is calculated above
'loss_inf': loss_inf.item(),
'loss_g2l': loss_g2l.item(),
'lgt_reg': res_dict['lgt_reg'].item(),
'loss_g2l_1t5': res_dict['g2l_1t5'].item(),
'loss_g2l_1t7': res_dict['g2l_1t7'].item(),
'loss_g2l_5t5': res_dict['g2l_5t5'].item()
},
n=1)
# shortcut diagnostics to deal with long epochs
total_updates += 1
epoch_updates += 1
if (total_updates % 100) == 0:
# IDK, maybe this helps?
torch.cuda.empty_cache()
time_stop = time.time()
spu = (time_stop - time_start) / 100.
print(
'Epoch {0:d}, {1:d} updates -- {2:.4f} sec/update'.format(
epoch, epoch_updates, spu))
time_start = time.time()
if (total_updates % 500) == 0:
# record diagnostics
eval_start = time.time()
fast_stats = AverageMeterSet(
) # Nawid - This is short term stats which are reset regularly
test(
model,
test_loader,
device,
fast_stats,
log_dir,
max_evals=100000
) # Nawd - test is chosen to be test_decoder_model or test_model at the start of the function based on whether decoder training is occuring or not
stat_tracker.record_stats(
fast_stats.averages(total_updates, prefix='fast/')
) # Nawid - This is used to record the data in tensorboard, where the average of the different values are placed in tensorboard,total_updates is the index which is used to place information in tensorbard i believe
eval_time = time.time() - eval_start
stat_str = fast_stats.pretty_string(ignore=model.tasks)
stat_str = '-- {0:d} updates, eval_time {1:.2f}: {2:s}'.format(
total_updates, eval_time, stat_str)
print(stat_str)
# update learning rate
scheduler_inf.step(epoch)
test(model,
test_loader,
device,
epoch_stats,
log_dir,
max_evals=500000)
epoch_str = epoch_stats.pretty_string(ignore=model.tasks)
diag_str = '{0:d}: {1:s}'.format(epoch, epoch_str)
print(diag_str)
sys.stdout.flush()
stat_tracker.record_stats(
epoch_stats.averages(epoch, prefix='costs/')
) # Nawid - This is used to update long-term stats which are used for a long-period of time
checkpointer.update(epoch + 1, total_updates)
