276 lines
10 KiB
Python
276 lines
10 KiB
Python
# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
|
|
#
|
|
# 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.
|
|
|
|
import unittest
|
|
|
|
import numpy as np
|
|
|
|
import paddle
|
|
from paddle.base import backward
|
|
|
|
|
|
class BackwardNet:
|
|
"""
|
|
Abstract Base Class.
|
|
All Net inherited this Class should implement two functions:
|
|
build_model: build net to test the logic of backward
|
|
init_data: fake input data to test all programs.
|
|
"""
|
|
|
|
def __init__(self):
|
|
self.stop_gradient_grad_vars = set()
|
|
self.no_grad_vars = set()
|
|
self.params_names = set()
|
|
self.op_path = []
|
|
|
|
def build_model(self):
|
|
"""
|
|
Build net to test the logic of backward.
|
|
:return: loss
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def init_data(self):
|
|
"""
|
|
Fake input data to test all programs.
|
|
:return: dict, {'var_name': var_data}
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
|
|
# TODO(Aurelius84): add conditional network test
|
|
class ConditionalNet(BackwardNet):
|
|
def __init__(self):
|
|
super().__init__()
|
|
|
|
|
|
class TestBackwardUninitializedVariable(unittest.TestCase):
|
|
"""this case is found in yolov5 while to_static.
|
|
gradient aggregation may cause sum a invalid variable.
|
|
"""
|
|
|
|
def test(self):
|
|
paddle.enable_static()
|
|
main_prg, startup_prg = paddle.static.Program(), paddle.static.Program()
|
|
with paddle.static.program_guard(main_prg, startup_prg):
|
|
gt = paddle.static.data(name='gt', shape=[4], dtype='float32')
|
|
x = paddle.static.data(name='x', shape=[2], dtype='float32')
|
|
gt.stop_gradient = True
|
|
x.stop_gradient = False
|
|
gt = gt.reshape([4, 1]).reshape([4])
|
|
loss = (
|
|
paddle.nn.functional.binary_cross_entropy(x, gt[:2])
|
|
+ (gt[2:4] * x).sum()
|
|
)
|
|
exe = paddle.static.Executor()
|
|
paddle.base.backward.gradients(loss, [])
|
|
exe.run(startup_prg)
|
|
# Optimizer
|
|
out = exe.run(
|
|
main_prg,
|
|
feed={
|
|
'gt': np.array([1.0, 1.0, 0.0, 0.0], dtype='float32'),
|
|
'x': np.array([0.5, 0.5], dtype='float32'),
|
|
},
|
|
fetch_list=[loss],
|
|
)
|
|
print(out)
|
|
|
|
|
|
class TestStripGradSuffix(unittest.TestCase):
|
|
def test_strip_grad_suffix(self):
|
|
cases = (
|
|
('x@GRAD', 'x'),
|
|
('x@GRAD@GRAD', 'x'),
|
|
('x@GRAD@RENAME@1', 'x'),
|
|
('x@GRAD_slice_0@GRAD', 'x@GRAD_slice_0'),
|
|
('grad/grad/x@GRAD@RENAME@block0@1@GRAD', 'x'),
|
|
)
|
|
for input_, desired in cases:
|
|
self.assertEqual(backward._strip_grad_suffix_(input_), desired)
|
|
|
|
|
|
class TestBackwardParamAlias(unittest.TestCase):
|
|
"""Test backward() with parameter alias: grad_tensor -> gradient"""
|
|
|
|
def setUp(self):
|
|
paddle.disable_static()
|
|
|
|
def test_backward_with_grad_tensor_param(self):
|
|
"""Test backward using grad_tensor parameter name."""
|
|
x = paddle.to_tensor([1.0, 2.0], dtype='float32', stop_gradient=False)
|
|
y = x**2
|
|
z = y.sum()
|
|
grad_tensor = paddle.to_tensor(1.0, dtype='float32')
|
|
z.backward(grad_tensor=grad_tensor)
|
|
expected = [2.0, 4.0]
|
|
np.testing.assert_allclose(x.grad.numpy(), expected, rtol=1e-5)
|
|
|
|
def test_backward_with_gradient_alias(self):
|
|
"""Test backward using gradient alias parameter name."""
|
|
x = paddle.to_tensor([1.0, 2.0], dtype='float32', stop_gradient=False)
|
|
y = x**2
|
|
z = y.sum()
|
|
grad_tensor = paddle.to_tensor(1.0, dtype='float32')
|
|
z.backward(gradient=grad_tensor)
|
|
expected = [2.0, 4.0]
|
|
np.testing.assert_allclose(x.grad.numpy(), expected, rtol=1e-5)
|
|
|
|
def test_backward_alias_with_custom_grad(self):
|
|
"""Test gradient alias with custom gradient values."""
|
|
x = paddle.to_tensor([[1.0, 2.0]], dtype='float32', stop_gradient=False)
|
|
y = x * 3
|
|
loss = y.sum()
|
|
custom_grad = paddle.to_tensor(2.0, dtype='float32')
|
|
loss.backward(gradient=custom_grad)
|
|
expected = [[6.0, 6.0]]
|
|
np.testing.assert_allclose(x.grad.numpy(), expected, rtol=1e-5)
|
|
|
|
def test_backward_alias_with_retain_graph(self):
|
|
"""Test gradient alias combined with retain_graph parameter."""
|
|
x = paddle.to_tensor([2.0], dtype='float32', stop_gradient=False)
|
|
y = x**2
|
|
loss = y.sum()
|
|
grad_tensor = paddle.to_tensor(1.0, dtype='float32')
|
|
loss.backward(gradient=grad_tensor, retain_graph=True)
|
|
expected = [4.0]
|
|
np.testing.assert_allclose(x.grad.numpy(), expected, rtol=1e-5)
|
|
x.clear_grad()
|
|
loss.backward(gradient=grad_tensor)
|
|
np.testing.assert_allclose(x.grad.numpy(), expected, rtol=1e-5)
|
|
|
|
def test_backward_alias_with_create_graph(self):
|
|
"""Test gradient alias combined with create_graph parameter."""
|
|
x = paddle.to_tensor([1.0], dtype='float32', stop_gradient=False)
|
|
y = x**2
|
|
loss = y.sum()
|
|
grad_tensor = paddle.to_tensor(1.0, dtype='float32')
|
|
loss.backward(gradient=grad_tensor, create_graph=True)
|
|
self.assertIsNotNone(x.grad)
|
|
np.testing.assert_allclose(x.grad.numpy(), [2.0], rtol=1e-5)
|
|
|
|
|
|
class TestBackwardCreateGraph(unittest.TestCase):
|
|
"""Test backward with create_graph parameter for higher-order gradients."""
|
|
|
|
def setUp(self):
|
|
paddle.disable_static()
|
|
|
|
def test_tensor_backward_with_create_graph(self):
|
|
"""Test backward with create_graph=True for second-order gradients"""
|
|
x = paddle.to_tensor(
|
|
np.array([[1.0, 2.0], [3.0, 4.0]]), dtype='float32'
|
|
)
|
|
x.stop_gradient = False
|
|
y = x * x
|
|
loss = paddle.sum(y)
|
|
# First backward with create_graph=True
|
|
loss.backward(create_graph=True)
|
|
# Verify first-order gradients
|
|
self.assertIsNotNone(x.grad)
|
|
first_grad = x.grad.numpy()
|
|
np.testing.assert_allclose(
|
|
first_grad, np.array([[2.0, 4.0], [6.0, 8.0]]), rtol=1e-7
|
|
)
|
|
# Compute second-order gradients
|
|
grad_sum = paddle.sum(x.grad)
|
|
grad_sum.backward()
|
|
# Verify second-order gradients
|
|
self.assertIsNotNone(x.grad)
|
|
second_grad = x.grad.numpy()
|
|
np.testing.assert_allclose(
|
|
second_grad, np.array([[4.0, 6.0], [8.0, 10.0]]), rtol=1e-7
|
|
)
|
|
|
|
def test_backward_create_graph_second_order(self):
|
|
"""Test computing second-order gradients using create_graph=True."""
|
|
x = paddle.to_tensor([1.0, 2.0], dtype='float32', stop_gradient=False)
|
|
y = x**2
|
|
loss = y.sum()
|
|
# First backward with create_graph=True
|
|
# x.grad should be [2.0, 4.0]
|
|
paddle.autograd.backward(loss, create_graph=True)
|
|
grad_sum = x.grad.sum()
|
|
grad_sum.backward()
|
|
# Check second-order gradients
|
|
# sum up to [4.0, 6.0]
|
|
self.assertIsNotNone(x.grad)
|
|
np.testing.assert_allclose(x.grad.numpy(), [4.0, 6.0], rtol=1e-5)
|
|
|
|
def test_backward_create_graph_with_multiple_tensors(self):
|
|
"""Test backward with create_graph on multiple output tensors."""
|
|
x = paddle.to_tensor(
|
|
[[1.0, 2.0], [3.0, 4.0]], dtype='float32', stop_gradient=False
|
|
)
|
|
z1 = x**2
|
|
z2 = x * 3
|
|
# Backward on z1
|
|
paddle.autograd.backward(z1, create_graph=True)
|
|
self.assertIsNotNone(x.grad)
|
|
self.assertFalse(x.grad.stop_gradient)
|
|
x.clear_grad()
|
|
# Backward on z2
|
|
paddle.autograd.backward(z2, create_graph=True)
|
|
self.assertIsNotNone(x.grad)
|
|
self.assertFalse(x.grad.stop_gradient)
|
|
|
|
def test_backward_create_graph_with_grad_tensors(self):
|
|
"""Test backward with create_graph and custom grad_tensors."""
|
|
x = paddle.to_tensor([1.0, 2.0], dtype='float32', stop_gradient=False)
|
|
y = x**2
|
|
z = y.sum()
|
|
grad_tensor = paddle.to_tensor([1.0, 2.0], dtype='float32')
|
|
paddle.autograd.backward(y, grad_tensors=grad_tensor, create_graph=True)
|
|
# Check gradients with custom weights
|
|
self.assertIsNotNone(x.grad)
|
|
expected = [2.0 * 1.0, 4.0 * 2.0] # dy/dx * weights
|
|
np.testing.assert_allclose(x.grad.numpy(), expected, rtol=1e-5)
|
|
self.assertFalse(x.grad.stop_gradient)
|
|
|
|
def test_backward_create_graph_retain_graph(self):
|
|
"""Test backward with create_graph=True and retain_graph=True."""
|
|
x = paddle.to_tensor([2.0], dtype='float32', stop_gradient=False)
|
|
y = x**3
|
|
loss = y.sum()
|
|
# First backward
|
|
paddle.autograd.backward(loss, create_graph=True, retain_graph=True)
|
|
grad1 = x.grad.clone()
|
|
x.clear_grad()
|
|
# Second backward with same graph
|
|
paddle.autograd.backward(loss, create_graph=True, retain_graph=False)
|
|
grad2 = x.grad
|
|
# Gradients should be the same
|
|
np.testing.assert_allclose(grad1.numpy(), grad2.numpy(), rtol=1e-5)
|
|
|
|
def test_backward_create_graph_chain_rule(self):
|
|
"""Test chain rule with higher-order gradients."""
|
|
x = paddle.to_tensor([1.0], dtype='float32', stop_gradient=False)
|
|
y = x**3
|
|
loss = y**2
|
|
# First backward
|
|
paddle.autograd.backward(loss, create_graph=True, retain_graph=True)
|
|
# At x=1: x.grad should be 6.0
|
|
np.testing.assert_allclose(x.grad.numpy(), [6.0], rtol=1e-5)
|
|
# Second backward
|
|
grad_sum = paddle.sum(x.grad)
|
|
paddle.autograd.backward(grad_sum)
|
|
# At x=1: x.grad should be 30
|
|
# Sum up to 36
|
|
np.testing.assert_allclose(x.grad.numpy(), [36.0], rtol=1e-5)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
paddle.enable_static()
|
|
unittest.main()
|