pytorch/caffe2/python/optimizer_test_util.py
Christopher Hay cc3662e939 Added support for scaling learning rate of Caffe2 optimizers during training
Summary: While there is currently support for scaling the base learning rate when loading the model, there is not support for scaling the base learning rate during training. This is needed for LATTE's seq2seq translation models, as the learning schedule is not predefined and is modified at runtime.

Reviewed By: jhcross

Differential Revision: D5701391

fbshipit-source-id: ae3bec45f238db1a2be7af9c04d720067e9095d5
2017-08-25 19:04:47 -07:00

240 lines
9.1 KiB
Python

## @package optimizer_test_util
# Module caffe2.python.optimizer_test_util
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
import unittest
import numpy as np
from caffe2.python import brew, core, workspace, cnn, optimizer
from caffe2.proto import caffe2_pb2
from caffe2.python.modeling.initializers import (
Initializer, pFP16Initializer)
from caffe2.python.model_helper import ModelHelper
class OptimizerTestBase(object):
"""
This is an abstract base class.
Don't inherit from unittest.TestCase, and don't name it 'Test*'.
Do, however, do these things in classes which inherit from this.
"""
def _createDense(self, dtype=core.DataType.FLOAT):
perfect_model = np.array([2, 6, 5, 0, 1]).astype(np.float32)
np.random.seed(123) # make test deterministic
numpy_dtype = np.float32 if dtype == core.DataType.FLOAT else np.float16
initializer = Initializer if dtype == core.DataType.FLOAT else pFP16Initializer
data = np.random.randint(
2,
size=(20, perfect_model.size)).astype(numpy_dtype)
label = np.dot(data, perfect_model)[:, np.newaxis]
model = ModelHelper(name="test", arg_scope={'order':'NCHW'})
out = brew.fc(
model,
'data', 'fc', perfect_model.size, 1, ('ConstantFill', {}),
('ConstantFill', {}), axis=0,
WeightInitializer=initializer, BiasInitializer=initializer
)
if dtype == core.DataType.FLOAT16:
out = model.HalfToFloat(out, out + "_fp32")
sq = model.SquaredL2Distance([out, 'label'])
loss = model.AveragedLoss(sq, "avg_loss")
grad_map = model.AddGradientOperators([loss])
self.assertIsInstance(grad_map['fc_w'], core.BlobReference)
return (model, perfect_model, data, label)
def testDense(self):
model, perfect_model, data, label = self._createDense()
optimizer = self.build_optimizer(model)
workspace.FeedBlob('data', data[0])
workspace.FeedBlob('label', label[0])
workspace.RunNetOnce(model.param_init_net)
workspace.CreateNet(model.net, True)
for _ in range(2000):
idx = np.random.randint(data.shape[0])
workspace.FeedBlob('data', data[idx])
workspace.FeedBlob('label', label[idx])
workspace.RunNet(model.net.Proto().name)
np.testing.assert_allclose(
perfect_model[np.newaxis, :],
workspace.FetchBlob('fc_w'),
atol=1e-2
)
self.check_optimizer(optimizer)
@unittest.skipIf(not workspace.has_gpu_support, "No gpu support")
def testGPUDense(self, dtype=core.DataType.FLOAT):
device_opt = core.DeviceOption(caffe2_pb2.CUDA, 0)
with core.DeviceScope(device_opt):
model, _perfect_model, data, label = self._createDense(dtype)
if dtype == core.DataType.FLOAT16:
fc_fp32_for_host = model.HalfToFloat('fc', 'fc_fp32_for_host')
model.CopyGPUToCPU(fc_fp32_for_host, 'fc_cpu')
else:
model.CopyGPUToCPU('fc', 'fc_cpu')
workspace.FeedBlob('data', data[0])
workspace.FeedBlob('label', label[0])
# Add some CPU ops
brew.fc(model, 'fc_cpu', 'fc2', dim_in=1, dim_out=10, axis=0)
# Create optimizer in default device scope
self.build_optimizer(model)
if self._skip_gpu:
return
# Run net to see it does not crash
workspace.RunNetOnce(model.param_init_net)
workspace.CreateNet(model.net, True)
workspace.RunNet(model.net.Proto().name)
def testSparse(self):
# to test duplicated indices we assign two indices to each weight and
# thus each weight might count once or twice
DUPLICATION = 2
perfect_model = np.array([2, 6, 5, 0, 1]).astype(np.float32)
np.random.seed(123) # make test deterministic
data = np.random.randint(
2,
size=(20, perfect_model.size * DUPLICATION)).astype(np.float32)
label = np.dot(data, np.repeat(perfect_model, DUPLICATION))
model = cnn.CNNModelHelper("NCHW", name="test")
# imitate what model wrapper does
w = model.param_init_net.ConstantFill(
[], 'w', shape=[perfect_model.size], value=0.0)
model.params.append(w)
picked = model.net.Gather([w, 'indices'], 'gather')
out = model.ReduceFrontSum(picked, 'sum')
sq = model.SquaredL2Distance([out, 'label'])
loss = model.AveragedLoss(sq, "avg_loss")
grad_map = model.AddGradientOperators([loss])
self.assertIsInstance(grad_map['w'], core.GradientSlice)
optimizer = self.build_optimizer(model)
workspace.CreateBlob('indices')
workspace.CreateBlob('label')
for indices_type in [np.int32, np.int64]:
workspace.RunNetOnce(model.param_init_net)
workspace.CreateNet(model.net, True)
for _ in range(2000):
idx = np.random.randint(data.shape[0])
# transform into indices of binary features
indices = np.repeat(np.arange(perfect_model.size),
DUPLICATION)[data[idx] == 1]
if indices.size == 0:
continue
workspace.FeedBlob(
'indices',
indices.reshape((indices.size,)).astype(indices_type)
)
workspace.FeedBlob('label',
np.array(label[idx]).astype(np.float32))
workspace.RunNet(model.net.Proto().name)
np.testing.assert_allclose(
perfect_model,
workspace.FetchBlob('w'),
atol=1e-2
)
self.check_optimizer(optimizer)
class LRModificationTestBase(object):
"""
This is an abstract base class.
Don't inherit from unittest.TestCase, and don't name it 'Test*'.
Do, however, do these things in classes which inherit from this.
"""
def _gradient_ratio_reference(self, model, params, max_gradient_norm):
from caffe2.python import core
sum_squared_norms = 0.0
for param in params:
grad = (
model.param_to_grad[param]
if not isinstance(
model.param_to_grad[param],
core.GradientSlice,
) else model.param_to_grad[param].values
)
val = workspace.FetchBlob(grad)
sum_squared_norms += np.power(np.linalg.norm(val), 2.0)
global_norm = np.sqrt(sum_squared_norms)
clip_norm = max_gradient_norm
norm_ratio = clip_norm / np.maximum(clip_norm, global_norm)
return norm_ratio
def test_global_norm_based_gradient_clipping(self):
max_gradient_norm = 1
model, perfect_model, data, label = self._createDense()
opt = self.build_optimizer(model, max_gradient_norm=max_gradient_norm)
params = []
for param in model.GetParams(top_scope=True):
if param in model.param_to_grad:
if not isinstance(
model.param_to_grad[param],
core.GradientSlice,
):
params.append(param)
workspace.FeedBlob('data', data[0])
workspace.FeedBlob('label', label[0])
workspace.RunNetOnce(model.param_init_net)
workspace.CreateNet(model.net, True)
self.assertIsNotNone(opt._lr_multiplier)
# Run net once
idx = np.random.randint(data.shape[0])
workspace.FeedBlob('data', data[idx])
workspace.FeedBlob('label', label[idx])
workspace.RunNet(model.net.Proto().name)
reference = self._gradient_ratio_reference(
model,
params,
max_gradient_norm,
)
norm_ratio = workspace.FetchBlob(
'norm_clipped_grad_update/norm_ratio')
np.testing.assert_almost_equal(norm_ratio, reference)
self.assertTrue(
reference < 1.0, "Bad test, gradient not being scaled."
)
def test_lr_injection(self):
model, perfect_model, data, label = self._createDense()
opt = self.build_optimizer(
model, max_gradient_norm=1, allow_lr_injection=True
)
workspace.FeedBlob('data', data[0])
workspace.FeedBlob('label', label[0])
workspace.RunNetOnce(model.param_init_net)
workspace.CreateNet(model.net, True)
# Test LR injection initialized properly
self.assertIsNotNone(opt._lr_multiplier)
self.assertEqual(optimizer.get_lr_injection(), 1)
# Test that we're able to modify the value of the lr_injection
optimizer.set_lr_injection(0)
self.assertEqual(optimizer.get_lr_injection(), 0)
# Test that setting the lr_injector properly propogates to the
# lr_multiplier. Here, we have both lr_injector and norm_ratio that
# affect the lr_multiplier
workspace.RunNet(model.net.Proto().name)
self.assertEqual(workspace.FetchBlob('lr_multiplier'), 0)