lightning/tests/utilities/test_grads.py

79 lines
2.7 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 unittest.mock import Mock
import pytest
import torch
import torch.nn as nn
from pytorch_lightning.utilities import grad_norm
@pytest.mark.parametrize(
"norm_type,expected",
[
(
1,
{"grad_1.0_norm/param0": 1 + 2 + 3, "grad_1.0_norm/param1": 4 + 5, "grad_1.0_norm_total": 15.0},
),
(
2,
{
"grad_2.0_norm/param0": pow(1 + 4 + 9, 0.5),
"grad_2.0_norm/param1": pow(16 + 25, 0.5),
"grad_2.0_norm_total": pow(1 + 4 + 9 + 16 + 25, 0.5),
},
),
(
3.14,
{
"grad_3.14_norm/param0": pow(1 + 2 ** 3.14 + 3 ** 3.14, 1 / 3.14),
"grad_3.14_norm/param1": pow(4 ** 3.14 + 5 ** 3.14, 1 / 3.14),
"grad_3.14_norm_total": pow(1 + 2 ** 3.14 + 3 ** 3.14 + 4 ** 3.14 + 5 ** 3.14, 1 / 3.14),
},
),
(
"inf",
{
"grad_inf_norm/param0": max(1, 2, 3),
"grad_inf_norm/param1": max(4, 5),
"grad_inf_norm_total": max(1, 2, 3, 4, 5),
},
),
],
)
def test_grad_norm(norm_type, expected):
"""Test utility function for computing the p-norm of individual parameter groups and norm in total."""
class Model(nn.Module):
def __init__(self):
super().__init__()
self.param0 = nn.Parameter(torch.rand(3))
self.param1 = nn.Parameter(torch.rand(2, 1))
self.param0.grad = torch.tensor([-1.0, 2.0, -3.0])
self.param1.grad = torch.tensor([[-4.0], [5.0]])
# param without grad should not contribute to norm
self.param2 = nn.Parameter(torch.rand(1))
model = Model()
norms = grad_norm(model, norm_type)
expected = {k: round(v, 4) for k, v in expected.items()}
assert norms == expected
@pytest.mark.parametrize("norm_type", [-1, 0])
def test_grad_norm_invalid_norm_type(norm_type):
with pytest.raises(ValueError, match="`norm_type` must be a positive number or 'inf'"):
grad_norm(Mock(), norm_type)