def gan_loss(G, D, imgs, recipe_embs, noisy_real, noisy_fake):
batch_size = imgs.shape[0]
z = torch.randn(batch_size, opts.LATENT_SIZE).to(opts.DEVICE)
imgs_gen = G(z, recipe_embs)
fake_probs = D(imgs_gen.detach(), recipe_embs)
real_probs = D(imgs, recipe_embs)
D_loss = BCELoss(fake_probs, noisy_fake) + BCELoss(real_probs, noisy_real)
all_real = Variable(FloatTensor(batch_size, 1).fill_(1.0), requires_grad=False).to(opts.DEVICE)
G_loss = BCELoss(fake_probs, all_real)
return D_loss, G_loss
def get_variables(recipe_ids, recipe_embs, img_ids, imgs, classes,
num_classes):
# Set up Variables
batch_size = imgs.shape[0]
recipe_embs = Variable(recipe_embs.type(FloatTensor)).to(opts.DEVICE)
imgs = Variable(imgs.type(FloatTensor)).to(opts.DEVICE)
classes = Variable(classes.type(LongTensor)).to(opts.DEVICE)
classes_one_hot = Variable(
FloatTensor(batch_size,
num_classes).zero_().scatter_(1, classes.view(-1, 1),
1)).to(opts.DEVICE)
return batch_size, recipe_embs, imgs, classes, classes_one_hot
def main():
# Load the data
data = GANstronomyDataset(opts.DATA_PATH, split=opts.TVT_SPLIT)
data.set_split_index(0)
data_loader = torch.utils.data.DataLoader(data,
batch_size=opts.BATCH_SIZE,
shuffle=True)
num_classes = data.num_classes()
# Make the output directory
util.create_dir(opts.RUN_PATH)
util.create_dir(opts.IMG_OUT_PATH)
util.create_dir(opts.MODEL_OUT_PATH)
# Copy opts.py and model.py to opts.RUN_PATH as a record
shutil.copy2('opts.py', opts.RUN_PATH)
shutil.copy2('model.py', opts.RUN_PATH)
shutil.copy2('train.py', opts.RUN_PATH)
# Instantiate the models
G = Generator(opts.EMBED_SIZE, num_classes).to(opts.DEVICE)
G_optimizer = torch.optim.Adam(G.parameters(),
lr=opts.ADAM_LR,
betas=opts.ADAM_B)
D = Discriminator(num_classes).to(opts.DEVICE)
D_optimizer = torch.optim.Adam(D.parameters(),
lr=opts.ADAM_LR,
betas=opts.ADAM_B)
if opts.MODEL_PATH is None:
start_iepoch, start_ibatch = 0, 0
else:
print('Attempting to resume training using model in %s...' %
opts.MODEL_PATH)
start_iepoch, start_ibatch = load_state_dicts(opts.MODEL_PATH, G,
G_optimizer, D,
D_optimizer)
for iepoch in range(opts.NUM_EPOCHS):
for ibatch, data_batch in enumerate(data_loader):
# To try to resume training, just continue if iepoch and ibatch are less than their starts
if iepoch < start_iepoch or (iepoch == start_iepoch
and ibatch < start_ibatch):
if iepoch % opts.INTV_PRINT_LOSS == 0 and not ibatch:
print('Skipping epoch %d...' % iepoch)
continue
recipe_ids, recipe_embs, img_ids, imgs, classes, noisy_real, noisy_fake = data_batch
# Make sure we're not training on validation or test data!
if opts.SAFETY_MODE:
for recipe_id in recipe_ids:
assert data.get_recipe_split_index(recipe_id) == 0
batch_size, recipe_embs, imgs, classes, classes_one_hot = util.get_variables(
recipe_ids, recipe_embs, img_ids, imgs, classes, num_classes)
noisy_real, noisy_fake = util.get_variables2(
noisy_real, noisy_fake)
# Adversarial ground truths
all_real = Variable(FloatTensor(batch_size, 1).fill_(1.0),
requires_grad=False).to(opts.DEVICE)
all_fake = Variable(FloatTensor(batch_size, 1).fill_(0.0),
requires_grad=False).to(opts.DEVICE)
# Train Generator
for _ in range(opts.NUM_UPDATE_G):
G_optimizer.zero_grad()
imgs_gen = G(recipe_embs, classes_one_hot)
fake_probs = D(imgs_gen, classes_one_hot)
G_BCE_loss = BCELoss(fake_probs, all_real)
G_MSE_loss = MSELoss(imgs_gen, imgs)
G_loss = opts.A_BCE * G_BCE_loss + opts.A_MSE * G_MSE_loss
G_loss.backward()
G_optimizer.step()
# Train Discriminator
for _ in range(opts.NUM_UPDATE_D):
D_optimizer.zero_grad()
fake_probs = D(imgs_gen.detach(), classes_one_hot)
real_probs = D(imgs, classes_one_hot)
D_loss = (
BCELoss(fake_probs,
noisy_fake if opts.NOISY_LABELS else all_fake) +
BCELoss(real_probs,
noisy_real if opts.NOISY_LABELS else all_real)) / 2
D_loss.backward()
D_optimizer.step()
if iepoch % opts.INTV_PRINT_LOSS == 0 and not ibatch:
print_loss(G_BCE_loss, G_MSE_loss, D_loss, iepoch)
if iepoch % opts.INTV_SAVE_IMG == 0 and not ibatch:
# Save a training image
get_img_gen(data, 0, G, iepoch, opts.IMG_OUT_PATH)
# Save a validation image
get_img_gen(data, 1, G, iepoch, opts.IMG_OUT_PATH)
if iepoch % opts.INTV_SAVE_MODEL == 0 and not ibatch:
print('Saving model...')
save_model(G, G_optimizer, D, D_optimizer, iepoch,
opts.MODEL_OUT_PATH)
save_model(G, G_optimizer, D, D_optimizer, 'FINAL', opts.MODEL_OUT_PATH)
print('\a') # Ring the bell to alert the human