def load(features_path, features_format, to_tensor=True, to_cuda=True):
loader = loaders[features_format]
features = loader(features_path)
if to_tensor:
features = torch.from_numpy(features)
if to_cuda:
features = to_cuda_if_available(features)
return features
def train(vae,
train_data,
test_data,
output_path,
output_loss_path,
batch_size=100,
start_epoch=0,
num_epochs=100,
l2_regularization=0.001,
learning_rate=0.001,
variable_sizes=None,
max_seconds_without_save=300):
start_time = time.time()
vae = to_cuda_if_available(vae)
optim = Adam(vae.parameters(),
weight_decay=l2_regularization,
lr=learning_rate)
logger = Logger(output_loss_path, append=start_epoch > 0)
saver = Saver({vae: output_path}, logger, max_seconds_without_save)
trainer = Trainer(vae, train_data, test_data, batch_size, optim,
variable_sizes)
for epoch_index in range(start_epoch, num_epochs):
# train vae
logger.start_timer()
train_losses = trainer.train()
logger.log(epoch_index, num_epochs, "vae", "train_mean_loss",
np.mean(train_losses))
# test imputation
logger.start_timer()
test_loss = trainer.test()
logger.log(epoch_index, num_epochs, "vae", "test_loss", test_loss)
# save models for the epoch
saver.delayed_save()
saver.save()
logger.close()
print("Total time: {:02f}s".format(time.time() - start_time))
def main(args=None):
options_parser = argparse.ArgumentParser(description="Impute missing values with iterative VAE. "
+ "Define 'temperature' to use multi-output.")
options_parser.add_argument("data", type=str, help="See 'data_format' parameter.")
options_parser.add_argument("metadata", type=str,
help="Information about the categorical variables in json format.")
options_parser.add_argument("model", type=str, help="Model input file.")
options_parser.add_argument("output_loss", type=str, help="Loss output file.")
options_parser.add_argument(
"--data_format",
type=str,
default="sparse",
choices=data_formats,
help="Either a dense numpy array, a sparse csr matrix or any of those formats in split into several files."
)
options_parser.add_argument(
"--split_size",
type=int,
default=128,
help="Dimension of the VAE latent space."
)
options_parser.add_argument(
"--code_size",
type=int,
default=128,
help="Dimension of the VAE latent space."
)
options_parser.add_argument(
"--encoder_hidden_sizes",
type=str,
default="",
help="Size of each hidden layer in the encoder separated by commas (no spaces)."
)
options_parser.add_argument(
"--decoder_hidden_sizes",
type=str,
default="",
help="Size of each hidden layer in the decoder separated by commas (no spaces)."
)
options_parser.add_argument(
"--max_iterations",
type=int,
default=1000,
help="Maximum number of iterations."
)
options_parser.add_argument(
"--tolerance",
type=float,
default=0.001,
help="Minimum RMSE to continue iterating."
)
options_parser.add_argument(
"--temperature",
type=float,
default=None,
help="Gumbel-Softmax temperature. Only used if metadata is also provided."
)
options_parser.add_argument(
"--missing_probability",
type=float,
default=0.5,
help="Probability of a value being missing."
)
options_parser.add_argument(
"--noise_learning_rate",
type=float,
help="Learning rate to use backpropagation and modify the noise."
)
options_parser.add_argument("--seed", type=int, help="Random number generator seed.", default=42)
options = options_parser.parse_args(args=args)
seed_all(options.seed)
variable_sizes = load_variable_sizes_from_metadata(options.metadata)
features = load(options.data, options.data_format)
mask = generate_mask_for(features, options.missing_probability, variable_sizes)
mask = to_cuda_if_available(mask)
if options.temperature is not None:
temperature = options.temperature
else:
temperature = None
vae = VAE(
features.shape[1],
options.split_size,
options.code_size,
encoder_hidden_sizes=parse_int_list(options.encoder_hidden_sizes),
decoder_hidden_sizes=parse_int_list(options.decoder_hidden_sizes),
variable_sizes=(None if temperature is None else variable_sizes), # do not use multi-output without temperature
temperature=temperature
)
load_without_cuda(vae, options.model)
impute(
vae,
features,
mask,
create_parent_directories_if_needed(options.output_loss),
max_iterations=options.max_iterations,
tolerance=options.tolerance,
variable_sizes=variable_sizes,
noise_learning_rate=options.noise_learning_rate
)
def impute(vae,
features,
mask,
output_loss_path,
max_iterations=1000,
tolerance=1e-3,
variable_sizes=None,
noise_learning_rate=None
):
start_time = time.time()
vae = to_cuda_if_available(vae)
logger = Logger(output_loss_path, append=False)
loss_function = MSELoss()
inverted_mask = 1 - mask
observed = features * mask
missing = torch.randn_like(features)
if noise_learning_rate is not None:
missing = Variable(missing, requires_grad=True)
optim = Adam([missing], weight_decay=0, lr=noise_learning_rate)
vae.train(mode=True)
for iteration in range(max_iterations):
logger.start_timer()
if noise_learning_rate is not None:
optim.zero_grad()
noisy_features = observed + missing * inverted_mask
_, reconstructed, _, _ = vae(noisy_features, training=True)
observed_loss = masked_reconstruction_loss_function(reconstructed,
features,
mask,
variable_sizes)
missing_loss = masked_reconstruction_loss_function(reconstructed,
features,
inverted_mask,
variable_sizes)
loss = torch.sqrt(loss_function(compose_with_mask(features, reconstructed, mask), features))
if noise_learning_rate is None:
missing = reconstructed * inverted_mask
else:
observed_loss.backward()
optim.step()
observed_loss, missing_loss, loss = to_cpu_if_available(observed_loss, missing_loss, loss)
observed_loss = observed_loss.data.numpy()
missing_loss = missing_loss.data.numpy()
loss = loss.data.numpy()
logger.log(iteration, max_iterations, "vae", "observed_loss", observed_loss)
logger.log(iteration, max_iterations, "vae", "missing_loss", missing_loss)
logger.log(iteration, max_iterations, "vae", "loss", loss)
if observed_loss < tolerance:
break
logger.close()
print("Total time: {:02f}s".format(time.time() - start_time))
def create_noisy_dataset(features, missing_probability, variable_sizes, return_all=False):
mask = generate_mask_for(features, missing_probability, variable_sizes)
mask = to_cuda_if_available(mask)
return NoisyDataset(features, mask, return_all=return_all)
def smooth_label_ones_like(batch):
smooth_label_ones = Variable(torch.FloatTensor(len(batch)).uniform_(0.9, 1))
return to_cuda_if_available(smooth_label_ones)
def label_zeros_like(batch):
label_zeros = Variable(torch.zeros(len(batch)))
return to_cuda_if_available(label_zeros)
def generate_noise(num_samples, num_features):
noise = Variable(torch.FloatTensor(num_samples, num_features).normal_())
return to_cuda_if_available(noise)
def generate_hint_for(mask, hint_probability, variable_sizes):
return mask * to_cuda_if_available(
generate_mask_for(mask, 1.0 - hint_probability, variable_sizes))
def train(
generator,
discriminator,
train_data,
test_data,
output_gen_path,
output_disc_path,
output_loss_path,
batch_size=64,
start_epoch=0,
num_epochs=10000,
num_disc_steps=1,
num_gen_steps=1,
l2_regularization=0,
learning_rate=0.001,
variable_sizes=None,
reconstruction_loss_weight=1,
hint_probability=0.9,
max_seconds_without_save=300,
early_stopping_patience=100,
):
start_time = time.time()
generator, discriminator = to_cuda_if_available(generator, discriminator)
optim_gen = Adam(generator.parameters(),
weight_decay=l2_regularization,
lr=learning_rate)
optim_disc = Adam(discriminator.parameters(),
weight_decay=l2_regularization,
lr=learning_rate)
logger = Logger(output_loss_path, append=start_epoch > 0)
saver = Saver({
generator: output_gen_path,
discriminator: output_disc_path
}, logger, max_seconds_without_save)
trainer = Trainer(train_data, test_data, generator, discriminator,
optim_gen, optim_disc, batch_size, variable_sizes,
num_disc_steps, num_gen_steps,
reconstruction_loss_weight, hint_probability)
# initialize early stopping
best_test_mean_loss = None
bad_epochs = 0
for epoch_index in range(start_epoch, num_epochs):
# train discriminator and generator
logger.start_timer()
disc_losses, gen_losses = trainer.train()
logger.log(epoch_index, num_epochs, "discriminator", "train_mean_loss",
np.mean(disc_losses))
logger.log(epoch_index, num_epochs, "generator", "train_mean_loss",
np.mean(gen_losses))
# test imputation
logger.start_timer()
reconstruction_losses = trainer.test()
test_mean_loss = np.mean(reconstruction_losses)
logger.log(epoch_index, num_epochs, "generator", "test_mean_loss",
test_mean_loss)
# check if the test loss is improving
if best_test_mean_loss is None or test_mean_loss < best_test_mean_loss:
best_test_mean_loss = test_mean_loss
bad_epochs = 0
# save models for the epoch
saver.delayed_save(keep_parameters=True)
# if the test loss is not improving check if early stopping should be executed
else:
bad_epochs += 1
if bad_epochs >= early_stopping_patience:
break
saver.save(only_use_kept=True)
logger.close()
print("Total time: {:02f}s".format(time.time() - start_time))
