lightning/pl_examples/basic_examples/autoencoder.py

116 lines
3.2 KiB
Python

# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from argparse import ArgumentParser
import torch
import torch.nn.functional as F
from torch import nn
from torch.utils.data import DataLoader, random_split
import pytorch_lightning as pl
from pl_examples import _TORCHVISION_AVAILABLE, cli_lightning_logo
if _TORCHVISION_AVAILABLE:
from torchvision import transforms
from torchvision.datasets.mnist import MNIST
else:
from tests.base.datasets import MNIST
class LitAutoEncoder(pl.LightningModule):
"""
>>> LitAutoEncoder() # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
LitAutoEncoder(
(encoder): ...
(decoder): ...
)
"""
def __init__(self):
super().__init__()
self.encoder = nn.Sequential(
nn.Linear(28 * 28, 64),
nn.ReLU(),
nn.Linear(64, 3),
)
self.decoder = nn.Sequential(
nn.Linear(3, 64),
nn.ReLU(),
nn.Linear(64, 28 * 28),
)
def forward(self, x):
# in lightning, forward defines the prediction/inference actions
embedding = self.encoder(x)
return embedding
def training_step(self, batch, batch_idx):
x, y = batch
x = x.view(x.size(0), -1)
z = self.encoder(x)
x_hat = self.decoder(z)
loss = F.mse_loss(x_hat, x)
return loss
def configure_optimizers(self):
optimizer = torch.optim.Adam(self.parameters(), lr=1e-3)
return optimizer
def cli_main():
pl.seed_everything(1234)
# ------------
# args
# ------------
parser = ArgumentParser()
parser.add_argument('--batch_size', default=32, type=int)
parser.add_argument('--hidden_dim', type=int, default=128)
parser = pl.Trainer.add_argparse_args(parser)
args = parser.parse_args()
# ------------
# data
# ------------
dataset = MNIST('', train=True, download=True, transform=transforms.ToTensor())
mnist_test = MNIST('', train=False, download=True, transform=transforms.ToTensor())
mnist_train, mnist_val = random_split(dataset, [55000, 5000])
train_loader = DataLoader(mnist_train, batch_size=args.batch_size)
val_loader = DataLoader(mnist_val, batch_size=args.batch_size)
test_loader = DataLoader(mnist_test, batch_size=args.batch_size)
# ------------
# model
# ------------
model = LitAutoEncoder()
# ------------
# training
# ------------
trainer = pl.Trainer.from_argparse_args(args)
trainer.fit(model, train_loader, val_loader)
# ------------
# testing
# ------------
result = trainer.test(test_dataloaders=test_loader)
print(result)
if __name__ == '__main__':
cli_lightning_logo()
cli_main()