lightning/tests/models/base.py

221 lines
7.2 KiB
Python

import os
from collections import OrderedDict
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch import optim
from torch.utils.data import DataLoader
from torch.utils.data.distributed import DistributedSampler
from torchvision import transforms
from torchvision.datasets import MNIST
try:
from test_tube import HyperOptArgumentParser
except ImportError:
# TODO: this should be discussed and moved out of this package
raise ImportError('Missing test-tube package.')
from pytorch_lightning.core.decorators import data_loader
from pytorch_lightning.core.lightning import LightningModule
class TestingMNIST(MNIST):
def __init__(self, root, train=True, transform=None, target_transform=None,
download=False, num_samples=8000):
super(TestingMNIST, self).__init__(
root,
train=train,
transform=transform,
target_transform=target_transform,
download=download
)
# take just a subset of MNIST dataset
self.data = self.data[:num_samples]
self.targets = self.targets[:num_samples]
class LightningTestModelBase(LightningModule):
"""
Base LightningModule for testing. Implements only the required
interface
"""
def __init__(self, hparams, force_remove_distributed_sampler=False):
"""
Pass in parsed HyperOptArgumentParser to the model
:param hparams:
"""
# init superclass
super(LightningTestModelBase, self).__init__()
self.hparams = hparams
self.batch_size = hparams.batch_size
# if you specify an example input, the summary will show input/output for each layer
self.example_input_array = torch.rand(5, 28 * 28)
# remove to test warning for dist sampler
self.force_remove_distributed_sampler = force_remove_distributed_sampler
# build model
self.__build_model()
# ---------------------
# MODEL SETUP
# ---------------------
def __build_model(self):
"""
Layout model
:return:
"""
self.c_d1 = nn.Linear(in_features=self.hparams.in_features,
out_features=self.hparams.hidden_dim)
self.c_d1_bn = nn.BatchNorm1d(self.hparams.hidden_dim)
self.c_d1_drop = nn.Dropout(self.hparams.drop_prob)
self.c_d2 = nn.Linear(in_features=self.hparams.hidden_dim,
out_features=self.hparams.out_features)
# ---------------------
# TRAINING
# ---------------------
def forward(self, x):
"""
No special modification required for lightning, define as you normally would
:param x:
:return:
"""
x = self.c_d1(x)
x = torch.tanh(x)
x = self.c_d1_bn(x)
x = self.c_d1_drop(x)
x = self.c_d2(x)
logits = F.log_softmax(x, dim=1)
return logits
def loss(self, labels, logits):
nll = F.nll_loss(logits, labels)
return nll
def training_step(self, batch, batch_idx):
"""
Lightning calls this inside the training loop
:param batch:
:return:
"""
# forward pass
x, y = batch
x = x.view(x.size(0), -1)
y_hat = self.forward(x)
# calculate loss
loss_val = self.loss(y, y_hat)
# in DP mode (default) make sure if result is scalar, there's another dim in the beginning
if self.trainer.use_dp:
loss_val = loss_val.unsqueeze(0)
# alternate possible outputs to test
if self.trainer.batch_idx % 1 == 0:
output = OrderedDict({
'loss': loss_val,
'progress_bar': {'some_val': loss_val * loss_val},
'log': {'train_some_val': loss_val * loss_val},
})
return output
if self.trainer.batch_idx % 2 == 0:
return loss_val
# ---------------------
# TRAINING SETUP
# ---------------------
def configure_optimizers(self):
"""
return whatever optimizers we want here.
:return: list of optimizers
"""
# try no scheduler for this model (testing purposes)
if self.hparams.optimizer_name == 'lbfgs':
optimizer = optim.LBFGS(self.parameters(), lr=self.hparams.learning_rate)
else:
optimizer = optim.Adam(self.parameters(), lr=self.hparams.learning_rate)
# test returning only 1 list instead of 2
return optimizer
def _dataloader(self, train):
# init data generators
transform = transforms.Compose([transforms.ToTensor(),
transforms.Normalize((0.5,), (1.0,))])
dataset = TestingMNIST(root=self.hparams.data_root, train=train,
transform=transform, download=True, num_samples=2000)
# when using multi-node we need to add the datasampler
train_sampler = None
batch_size = self.hparams.batch_size
try:
if self.use_ddp and not self.force_remove_distributed_sampler:
train_sampler = DistributedSampler(dataset, rank=self.trainer.proc_rank)
batch_size = batch_size // self.trainer.world_size # scale batch size
except Exception:
pass
should_shuffle = train_sampler is None
loader = DataLoader(
dataset=dataset,
batch_size=batch_size,
shuffle=should_shuffle,
sampler=train_sampler
)
return loader
@data_loader
def train_dataloader(self):
return self._dataloader(train=True)
@staticmethod
def add_model_specific_args(parent_parser, root_dir): # pragma: no cover
"""
Parameters you define here will be available to your model through self.hparams
:param parent_parser:
:param root_dir:
:return:
"""
parser = HyperOptArgumentParser(strategy=parent_parser.strategy, parents=[parent_parser])
# param overwrites
# parser.set_defaults(gradient_clip_val=5.0)
# network params
parser.opt_list('--drop_prob', default=0.2, options=[0.2, 0.5], type=float, tunable=False)
parser.add_argument('--in_features', default=28 * 28, type=int)
parser.add_argument('--out_features', default=10, type=int)
# use 500 for CPU, 50000 for GPU to see speed difference
parser.add_argument('--hidden_dim', default=50000, type=int)
# data
parser.add_argument('--data_root', default=os.path.join(root_dir, 'mnist'), type=str)
# training params (opt)
parser.opt_list('--learning_rate', default=0.001 * 8, type=float,
options=[0.0001, 0.0005, 0.001, 0.005],
tunable=False)
parser.opt_list('--optimizer_name', default='adam', type=str,
options=['adam'], tunable=False)
# if using 2 nodes with 4 gpus each the batch size here
# (256) will be 256 / (2*8) = 16 per gpu
parser.opt_list('--batch_size', default=256 * 8, type=int,
options=[32, 64, 128, 256], tunable=False,
help='batch size will be divided over all gpus being used across all nodes')
return parser