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pytorch / examples UNCLAIMED

A set of examples around pytorch in Vision, Text, Reinforcement Learning, etc.

23827 0 0 Python
#include <torch/torch.h>
#include <argparse/argparse.hpp>
#include <cmath>
#include <cstdio>
#include <iostream>
// The size of the noise vector fed to the generator.
const int64_t kNoiseSize = 100;
// The batch size for training.
const int64_t kBatchSize = 64;
// Where to find the MNIST dataset.
const char* kDataFolder = "./data";
// After how many batches to create a new checkpoint periodically.
const int64_t kCheckpointEvery = 200;
// How many images to sample at every checkpoint.
const int64_t kNumberOfSamplesPerCheckpoint = 10;
// Set to `true` to restore models and optimizers from previously saved
// checkpoints.
const bool kRestoreFromCheckpoint = false;
// After how many batches to log a new update with the loss value.
const int64_t kLogInterval = 10;
using namespace torch;
struct DCGANGeneratorImpl : nn::Module {
DCGANGeneratorImpl(int kNoiseSize)
: conv1(nn::ConvTranspose2dOptions(kNoiseSize, 256, 4)
.bias(false)),
batch_norm1(256),
conv2(nn::ConvTranspose2dOptions(256, 128, 3)
.stride(2)
.padding(1)
.bias(false)),
batch_norm2(128),
conv3(nn::ConvTranspose2dOptions(128, 64, 4)
.stride(2)
.padding(1)
.bias(false)),
batch_norm3(64),
conv4(nn::ConvTranspose2dOptions(64, 1, 4)
.stride(2)
.padding(1)
.bias(false))
{
// register_module() is needed if we want to use the parameters() method later on
register_module("conv1", conv1);
register_module("conv2", conv2);
register_module("conv3", conv3);
register_module("conv4", conv4);
register_module("batch_norm1", batch_norm1);
register_module("batch_norm2", batch_norm2);
register_module("batch_norm3", batch_norm3);
}
torch::Tensor forward(torch::Tensor x) {
x = torch::relu(batch_norm1(conv1(x)));
x = torch::relu(batch_norm2(conv2(x)));
x = torch::relu(batch_norm3(conv3(x)));
x = torch::tanh(conv4(x));
return x;
}
nn::ConvTranspose2d conv1, conv2, conv3, conv4;
nn::BatchNorm2d batch_norm1, batch_norm2, batch_norm3;
};
TORCH_MODULE(DCGANGenerator);
nn::Sequential create_discriminator() {
return nn::Sequential(
// Layer 1
nn::Conv2d(nn::Conv2dOptions(1, 64, 4).stride(2).padding(1).bias(false)),
nn::LeakyReLU(nn::LeakyReLUOptions().negative_slope(0.2)),
// Layer 2
nn::Conv2d(nn::Conv2dOptions(64, 128, 4).stride(2).padding(1).bias(false)),
nn::BatchNorm2d(128),
nn::LeakyReLU(nn::LeakyReLUOptions().negative_slope(0.2)),
// Layer 3
nn::Conv2d(
nn::Conv2dOptions(128, 256, 4).stride(2).padding(1).bias(false)),
nn::BatchNorm2d(256),
nn::LeakyReLU(nn::LeakyReLUOptions().negative_slope(0.2)),
// Layer 4
nn::Conv2d(nn::Conv2dOptions(256, 1, 3).stride(1).padding(0).bias(false)),
nn::Sigmoid());
}
int main(int argc, const char* argv[]) {
argparse::ArgumentParser parser("cpp/dcgan example");
parser.add_argument("--epochs")
.help("Number of epochs to train")
.default_value(std::int64_t{30})
.scan<'i', int64_t>();
try {
parser.parse_args(argc, argv);
} catch (const std::exception& err) {
std::cout << err.what() << std::endl;
std::cout << parser;
std::exit(1);
}
// The number of epochs to train, default value is 30.
const int64_t kNumberOfEpochs = parser.get<int64_t>("--epochs");
std::cout << "Traning with number of epochs: " << kNumberOfEpochs
<< std::endl;
torch::manual_seed(1);
// Create the device we pass around based on whether CUDA is available.
torch::Device device(torch::kCPU);
if (torch::cuda::is_available()) {
std::cout << "CUDA is available! Training on GPU." << std::endl;
device = torch::Device(torch::kCUDA);
}
DCGANGenerator generator(kNoiseSize);
generator->to(device);
nn::Sequential discriminator = create_discriminator();
discriminator->to(device);
// Assume the MNIST dataset is available under `kDataFolder`;
auto dataset = torch::data::datasets::MNIST(kDataFolder)
.map(torch::data::transforms::Normalize<>(0.5, 0.5))
.map(torch::data::transforms::Stack<>());
const int64_t batches_per_epoch = static_cast<int64_t>(
std::ceil(dataset.size().value() / static_cast<double>(kBatchSize)));
auto data_loader = torch::data::make_data_loader(
std::move(dataset),
torch::data::DataLoaderOptions().batch_size(kBatchSize).workers(2));
torch::optim::Adam generator_optimizer(
generator->parameters(), torch::optim::AdamOptions(2e-4).betas(std::make_tuple (0.5, 0.5)));
torch::optim::Adam discriminator_optimizer(
discriminator->parameters(), torch::optim::AdamOptions(2e-4).betas(std::make_tuple (0.5, 0.5)));
if (kRestoreFromCheckpoint) {
torch::load(generator, "generator-checkpoint.pt");
torch::load(generator_optimizer, "generator-optimizer-checkpoint.pt");
torch::load(discriminator, "discriminator-checkpoint.pt");
torch::load(
discriminator_optimizer, "discriminator-optimizer-checkpoint.pt");
}
int64_t checkpoint_counter = 1;
for (int64_t epoch = 1; epoch <= kNumberOfEpochs; ++epoch) {
int64_t batch_index = 0;
for (const torch::data::Example<>& batch : *data_loader) {
// Train discriminator with real images.
discriminator->zero_grad();
torch::Tensor real_images = batch.data.to(device);
torch::Tensor real_labels =
torch::empty(batch.data.size(0), device).uniform_(0.8, 1.0);
torch::Tensor real_output = discriminator->forward(real_images).reshape(real_labels.sizes());
torch::Tensor d_loss_real =
torch::binary_cross_entropy(real_output, real_labels);
d_loss_real.backward();
// Train discriminator with fake images.
torch::Tensor noise =
torch::randn({batch.data.size(0), kNoiseSize, 1, 1}, device);
torch::Tensor fake_images = generator->forward(noise);
torch::Tensor fake_labels = torch::zeros(batch.data.size(0), device);
torch::Tensor fake_output = discriminator->forward(fake_images.detach()).reshape(fake_labels.sizes());
torch::Tensor d_loss_fake =
torch::binary_cross_entropy(fake_output, fake_labels);
d_loss_fake.backward();
torch::Tensor d_loss = d_loss_real + d_loss_fake;
discriminator_optimizer.step();
// Train generator.
generator->zero_grad();
fake_labels.fill_(1);
fake_output = discriminator->forward(fake_images).reshape(fake_labels.sizes());
torch::Tensor g_loss =
torch::binary_cross_entropy(fake_output, fake_labels);
g_loss.backward();
generator_optimizer.step();
batch_index++;
if (batch_index % kLogInterval == 0) {
std::printf(
2019-04-10 23:02:53 +08:00
"\r[%2ld/%2ld][%3ld/%3ld] D_loss: %.4f | G_loss: %.4f\n",
epoch,
kNumberOfEpochs,
batch_index,
batches_per_epoch,
d_loss.item<float>(),
g_loss.item<float>());
}
if (batch_index % kCheckpointEvery == 0) {
// Checkpoint the model and optimizer state.
torch::save(generator, "generator-checkpoint.pt");
torch::save(generator_optimizer, "generator-optimizer-checkpoint.pt");
torch::save(discriminator, "discriminator-checkpoint.pt");
torch::save(
discriminator_optimizer, "discriminator-optimizer-checkpoint.pt");
// Sample the generator and save the images.
torch::Tensor samples = generator->forward(torch::randn(
{kNumberOfSamplesPerCheckpoint, kNoiseSize, 1, 1}, device));
torch::save(
(samples + 1.0) / 2.0,
torch::str("dcgan-sample-", checkpoint_counter, ".pt"));
std::cout << "\n-> checkpoint " << ++checkpoint_counter << '\n';
}
}
}
std::cout << "Training complete!" << std::endl;
}