-
Notifications
You must be signed in to change notification settings - Fork 3.2k
/
smoothing.py
40 lines (34 loc) · 1.33 KB
/
smoothing.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
# Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the BSD 3-Clause License (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://opensource.org/licenses/BSD-3-Clause
#
# 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 torch
import torch.nn as nn
class LabelSmoothing(nn.Module):
"""
NLL loss with label smoothing.
"""
def __init__(self, smoothing=0.0):
"""
Constructor for the LabelSmoothing module.
:param smoothing: label smoothing factor
"""
super(LabelSmoothing, self).__init__()
self.confidence = 1.0 - smoothing
self.smoothing = smoothing
def forward(self, x, target):
logprobs = torch.nn.functional.log_softmax(x, dim=-1)
nll_loss = -logprobs.gather(dim=-1, index=target.unsqueeze(1))
nll_loss = nll_loss.squeeze(1)
smooth_loss = -logprobs.mean(dim=-1)
loss = self.confidence * nll_loss + self.smoothing * smooth_loss
return loss.mean()