Files
pytorch-lightning/pytorch_lightning/trainer/evaluation_loop.py
T
3e8f2d99a9 Progress bar callback (#1450)
* squash and rebase

sanity check hooks


sanity check callback hook finish


moved core progress bar functionality into callback


wip


remove duplicate merge


clean up


imports


docs


sanity check progress bar main


sanity


move callback calls


init progrss bar callback


configuration and docs


changelog


rate decorator


pass process_position


disable on rank > 0


position index


is_enabled


remove decorator


refactor init tqdm bars


callback method ordering 


cannot reset when disabled


sequence -> list


default values


fix has no attr _time() 


move on_val_end to proper place


fix the pickle issue


update warning


properties


check for None


remove old comment


switch order


pull out non-tqdm functionality into base class


documentation for the base class


docs


fix refresh rate issue in validation


restrict type hint of trainer arg


more docs


update trainer docs


rst docs


fix lines too long


fix test


add missing type hints


fix typo


move docstring to __init__ solves doctest failures


remove doctest :(( can't fix the pickle error


fix example


simplify by saving trainer reference


fix docs errors


move docstring


initial value


multiple val checks per epoch


simpler handling of inf dataset sizes


update inf docs


renamed training_tqdm_dict


rename get_tqdm_dict


rename occurences of tqdm 


update changelog


fix doctest


fix formatting errors


added callback tests


progress bar on off test


more tests for progress bar


weird test fix?


add ignored property


disable default progress bar in LR finder


change enable/disable behavior


trying doctest in CI again


undo doctest pickle error


undo doctest pickle error :((


remove progress_bar_callback Trainer arg and fix tests


restore progress bar after auto lr find


update docs


fix rebase


fix wrong negation

* fix fast dev run total

* more thorough testing

* remove old args

* fix merge

* fix merge

* separate tests

* type hint total batches

* reduce if

Co-Authored-By: Jirka Borovec <Borda@users.noreply.github.com>

* is_disabled

Co-Authored-By: Jirka Borovec <Borda@users.noreply.github.com>

* is_enabled

Co-Authored-By: Jirka Borovec <Borda@users.noreply.github.com>

* rename enabled/disabled

* move deprecated api

* remove duplicated test from merge

* fix rename is_disabled

* newline

* test also testprogress for fast dev run

Co-authored-by: J. Borovec <jirka.borovec@seznam.cz>
Co-authored-by: Jirka Borovec <Borda@users.noreply.github.com>
2020-04-23 20:46:18 -04:00

450 lines
14 KiB
Python

"""
Validation loop
===============
The lightning validation loop handles everything except the actual computations of your model.
To decide what will happen in your validation loop, define the `validation_step` function.
Below are all the things lightning automates for you in the validation loop.
.. note:: Lightning will run 5 steps of validation in the beginning of training as a sanity
check so you don't have to wait until a full epoch to catch possible validation issues.
Check validation every n epochs
-------------------------------
If you have a small dataset you might want to check validation every n epochs
.. code-block:: python
# DEFAULT
trainer = Trainer(check_val_every_n_epoch=1)
Set how much of the validation set to check
-------------------------------------------
If you don't want to check 100% of the validation set (for debugging or if it's huge), set this flag
val_percent_check will be overwritten by overfit_pct if `overfit_pct > 0`
.. code-block:: python
# DEFAULT
trainer = Trainer(val_percent_check=1.0)
# check 10% only
trainer = Trainer(val_percent_check=0.1)
Set how much of the test set to check
-------------------------------------
If you don't want to check 100% of the test set (for debugging or if it's huge), set this flag
test_percent_check will be overwritten by overfit_pct if `overfit_pct > 0`
.. code-block:: python
# DEFAULT
trainer = Trainer(test_percent_check=1.0)
# check 10% only
trainer = Trainer(test_percent_check=0.1)
Set validation check frequency within 1 training epoch
------------------------------------------------------
For large datasets it's often desirable to check validation multiple times within a training loop.
Pass in a float to check that often within 1 training epoch.
Pass in an int k to check every k training batches. Must use an int if using an IterableDataset.
.. code-block:: python
# DEFAULT
trainer = Trainer(val_check_interval=0.95)
# check every .25 of an epoch
trainer = Trainer(val_check_interval=0.25)
# check every 100 train batches (ie: for IterableDatasets or fixed frequency)
trainer = Trainer(val_check_interval=100)
Set the number of validation sanity steps
-----------------------------------------
Lightning runs a few steps of validation in the beginning of training.
This avoids crashing in the validation loop sometime deep into a lengthy training loop.
.. code-block:: python
# DEFAULT
trainer = Trainer(num_sanity_val_steps=5)
You can use `Trainer(num_sanity_val_steps=0)` to skip the sanity check.
# Testing loop
To ensure you don't accidentally use test data to guide training decisions Lightning
makes running the test set deliberate.
**test**
You have two options to run the test set.
First case is where you test right after a full training routine.
.. code-block:: python
# run full training
trainer.fit(model)
# run test set
trainer.test()
Second case is where you load a model and run the test set
.. code-block:: python
model = MyLightningModule.load_from_metrics(
weights_path='/path/to/pytorch_checkpoint.ckpt',
tags_csv='/path/to/test_tube/experiment/version/meta_tags.csv',
on_gpu=True,
map_location=None
)
# init trainer with whatever options
trainer = Trainer(...)
# test (pass in the model)
trainer.test(model)
In this second case, the options you pass to trainer will be used when running
the test set (ie: 16-bit, dp, ddp, etc...)
"""
from abc import ABC, abstractmethod
from pprint import pprint
from typing import Callable
import torch
from torch.utils.data import DataLoader
from pytorch_lightning.core.lightning import LightningModule
from pytorch_lightning.overrides.data_parallel import LightningDistributedDataParallel, LightningDataParallel
from pytorch_lightning.utilities.exceptions import MisconfigurationException
from pytorch_lightning.utilities import rank_zero_warn
try:
import torch_xla.distributed.parallel_loader as xla_pl
import torch_xla.core.xla_model as xm
except ImportError:
XLA_AVAILABLE = False
else:
XLA_AVAILABLE = True
try:
import horovod.torch as hvd
except ImportError:
HOROVOD_AVAILABLE = False
else:
HOROVOD_AVAILABLE = True
class TrainerEvaluationLoopMixin(ABC):
# this is just a summary on variables used in this abstract class,
# the proper values/initialisation should be done in child class
on_gpu: bool
use_ddp: bool
use_dp: bool
use_ddp2: bool
use_horovod: bool
single_gpu: bool
data_parallel_device_ids: ...
model: LightningModule
num_test_batches: int
num_val_batches: int
fast_dev_run: ...
process_output: ...
progress_bar_dict: ...
proc_rank: int
current_epoch: int
callback_metrics: ...
test_dataloaders: DataLoader
val_dataloaders: DataLoader
use_tpu: bool
reload_dataloaders_every_epoch: ...
# Callback system
on_validation_batch_start: Callable
on_validation_batch_end: Callable
on_test_batch_start: Callable
on_test_batch_end: Callable
on_validation_start: Callable
on_validation_end: Callable
on_test_start: Callable
on_test_end: Callable
@abstractmethod
def copy_trainer_model_properties(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def get_model(self):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def is_overriden(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def transfer_batch_to_tpu(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def transfer_batch_to_gpu(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def add_progress_bar_metrics(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def log_metrics(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def reset_test_dataloader(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
@abstractmethod
def reset_val_dataloader(self, *args):
"""Warning: this is just empty shell for code implemented in other class."""
def _evaluate(self, model: LightningModule, dataloaders, max_batches: int, test_mode: bool = False):
"""Run evaluation code.
Args:
model: PT model
dataloaders: list of PT dataloaders
max_batches: Scalar
test_mode:
"""
# enable eval mode
model.zero_grad()
model.eval()
# copy properties for forward overrides
self.copy_trainer_model_properties(model)
# disable gradients to save memory
torch.set_grad_enabled(False)
# bookkeeping
outputs = []
# run validation
for dataloader_idx, dataloader in enumerate(dataloaders):
dl_outputs = []
# on TPU we have to wrap it under the ParallelLoader
if self.use_tpu:
device = xm.xla_device()
dataloader = xla_pl.ParallelLoader(dataloader, [device])
dataloader = dataloader.per_device_loader(device)
for batch_idx, batch in enumerate(dataloader):
if batch is None:
continue
# stop short when on fast_dev_run (sets max_batch=1)
if batch_idx >= max_batches:
break
# callbacks
if test_mode:
self.on_test_batch_start()
else:
self.on_validation_batch_start()
# -----------------
# RUN EVALUATION STEP
# -----------------
if self.use_amp and self.use_native_amp:
with torch.cuda.amp.autocast():
output = self.evaluation_forward(model, batch, batch_idx, dataloader_idx, test_mode)
else:
output = self.evaluation_forward(model, batch, batch_idx, dataloader_idx, test_mode)
# on dp / ddp2 might still want to do something with the batch parts
if test_mode:
if self.is_overriden('test_step_end'):
model_ref = self.get_model()
with self.profiler.profile('test_step_end'):
output = model_ref.test_step_end(output)
self.on_test_batch_end()
else:
if self.is_overriden('validation_step_end'):
model_ref = self.get_model()
with self.profiler.profile('validation_step_end'):
output = model_ref.validation_step_end(output)
self.on_validation_batch_end()
# track outputs for collation
dl_outputs.append(output)
outputs.append(dl_outputs)
eval_results = {}
# with a single dataloader don't pass an array
if len(dataloaders) == 1:
outputs = outputs[0]
# give model a chance to do something with the outputs (and method defined)
if isinstance(model, (LightningDistributedDataParallel, LightningDataParallel)):
model = model.module
if test_mode:
if self.is_overriden('test_end', model=model):
# TODO: remove in v1.0.0
eval_results = model.test_end(outputs)
rank_zero_warn('Method `test_end` was deprecated in v0.7 and will be removed v1.0.'
' Use `test_epoch_end` instead.', DeprecationWarning)
elif self.is_overriden('test_epoch_end', model=model):
eval_results = model.test_epoch_end(outputs)
else:
if self.is_overriden('validation_end', model=model):
# TODO: remove in v1.0.0
eval_results = model.validation_end(outputs)
rank_zero_warn('Method `validation_end` was deprecated in v0.7 and will be removed v1.0.'
' Use `validation_epoch_end` instead.', DeprecationWarning)
elif self.is_overriden('validation_epoch_end', model=model):
eval_results = model.validation_epoch_end(outputs)
# enable train mode again
model.train()
# enable gradients to save memory
torch.set_grad_enabled(True)
return eval_results
def run_evaluation(self, test_mode: bool = False):
# when testing make sure user defined a test step
if test_mode and not self.is_overriden('test_step'):
raise MisconfigurationException(
"You called `.test()` without defining model's `.test_step()`."
" Please define and try again")
# hook
model = self.get_model()
model.on_pre_performance_check()
# select dataloaders
if test_mode:
if self.test_dataloaders is None:
self.reset_test_dataloader(model)
dataloaders = self.test_dataloaders
max_batches = self.num_test_batches
else:
# val
if self.val_dataloaders is None:
self.reset_val_dataloader(model)
dataloaders = self.val_dataloaders
max_batches = self.num_val_batches
# cap max batches to 1 when using fast_dev_run
if self.fast_dev_run:
max_batches = 1
# Validation/Test begin callbacks
if test_mode:
self.on_test_start()
else:
self.on_validation_start()
# run evaluation
eval_results = self._evaluate(self.model, dataloaders, max_batches, test_mode)
_, prog_bar_metrics, log_metrics, callback_metrics, _ = self.process_output(eval_results)
# add metrics to prog bar
self.add_progress_bar_metrics(prog_bar_metrics)
# log results of test
if test_mode and self.proc_rank == 0:
print('-' * 80)
print('TEST RESULTS')
pprint(callback_metrics)
print('-' * 80)
# log metrics
self.log_metrics(log_metrics, {})
# track metrics for callbacks
self.callback_metrics.update(callback_metrics)
# hook
model.on_post_performance_check()
# eventual dataset reloading
if test_mode:
if self.reload_dataloaders_every_epoch:
self.reset_test_dataloader(model)
else:
# val
if self.reload_dataloaders_every_epoch:
self.reset_val_dataloader(model)
# Validation/Test end callbacks
if test_mode:
self.on_test_end()
else:
self.on_validation_end()
def evaluation_forward(self, model, batch, batch_idx, dataloader_idx, test_mode: bool = False):
# make dataloader_idx arg in validation_step optional
args = [batch, batch_idx]
if (test_mode and len(self.test_dataloaders) > 1) \
or (not test_mode and len(self.val_dataloaders) > 1):
args.append(dataloader_idx)
# handle DP, DDP forward
if self.use_ddp or self.use_dp or self.use_ddp2:
output = model(*args)
return output
# Horovod
if self.use_horovod and self.on_gpu:
batch = self.transfer_batch_to_gpu(batch, hvd.local_rank())
args[0] = batch
# single GPU data transfer
if self.single_gpu:
# for single GPU put inputs on gpu manually
root_gpu = 0
if isinstance(self.data_parallel_device_ids, list):
root_gpu = self.data_parallel_device_ids[0]
batch = self.transfer_batch_to_gpu(batch, root_gpu)
args[0] = batch
# TPU data transfer
if self.use_tpu:
batch = self.transfer_batch_to_tpu(batch)
args[0] = batch
# CPU, TPU or gpu step
if test_mode:
output = model.test_step(*args)
else:
output = model.validation_step(*args)
return output