lightning/pl_examples/basic_examples/simple_image_classifier.py

117 lines
3.3 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
from pprint import pprint
import torch
from torch.nn import functional as F
import pytorch_lightning as pl
from pl_examples import cli_lightning_logo
from pl_examples.basic_examples.mnist_datamodule import MNISTDataModule
class LitClassifier(pl.LightningModule):
"""
>>> LitClassifier() # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
LitClassifier(
(l1): Linear(...)
(l2): Linear(...)
)
"""
def __init__(self, hidden_dim=128, learning_rate=1e-3):
super().__init__()
self.save_hyperparameters()
self.l1 = torch.nn.Linear(28 * 28, self.hparams.hidden_dim)
self.l2 = torch.nn.Linear(self.hparams.hidden_dim, 10)
def forward(self, x):
x = x.view(x.size(0), -1)
x = torch.relu(self.l1(x))
x = torch.relu(self.l2(x))
return x
def training_step(self, batch, batch_idx):
x, y = batch
y_hat = self(x)
loss = F.cross_entropy(y_hat, y)
return loss
def validation_step(self, batch, batch_idx):
x, y = batch
y_hat = self(x)
loss = F.cross_entropy(y_hat, y)
self.log('valid_loss', loss)
def test_step(self, batch, batch_idx):
x, y = batch
y_hat = self(x)
loss = F.cross_entropy(y_hat, y)
self.log('test_loss', loss)
def configure_optimizers(self):
return torch.optim.Adam(self.parameters(), lr=self.hparams.learning_rate)
@staticmethod
def add_model_specific_args(parent_parser):
parser = ArgumentParser(parents=[parent_parser], add_help=False)
parser.add_argument('--hidden_dim', type=int, default=128)
parser.add_argument('--learning_rate', type=float, default=0.0001)
return parser
def cli_main():
pl.seed_everything(1234)
# ------------
# args
# ------------
parser = ArgumentParser()
parser = pl.Trainer.add_argparse_args(parser)
parser = LitClassifier.add_model_specific_args(parser)
parser = MNISTDataModule.add_argparse_args(parser)
args = parser.parse_args()
# ------------
# data
# ------------
dm = MNISTDataModule.from_argparse_args(args)
# ------------
# model
# ------------
model = LitClassifier(args.hidden_dim, args.learning_rate)
# ------------
# training
# ------------
trainer = pl.Trainer.from_argparse_args(args)
trainer.fit(model, datamodule=dm)
# ------------
# testing
# ------------
# todo: without passing model it fails for missing best weights
# MisconfigurationException, 'ckpt_path is "best", but ModelCheckpoint is not configured to save the best model.'
result = trainer.test(model, datamodule=dm)
pprint(result)
if __name__ == '__main__':
cli_lightning_logo()
cli_main()