PaddleClas/ppcls/utils/ema.py

43 lines
1.5 KiB
Python

# Copyright (c) 2021 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.
from copy import deepcopy
import paddle
class ExponentialMovingAverage():
"""
Exponential Moving Average
Code was heavily based on https://github.com/rwightman/pytorch-image-models/blob/master/timm/utils/model_ema.py
"""
def __init__(self, model, decay=0.9999):
super().__init__()
# make a copy of the model for accumulating moving average of weights
self.module = deepcopy(model)
self.module.eval()
self.decay = decay
@paddle.no_grad()
def _update(self, model, update_fn):
for ema_v, model_v in zip(self.module.state_dict().values(), model.state_dict().values()):
ema_v.set_value(update_fn(ema_v, model_v))
def update(self, model):
self._update(model, update_fn=lambda e, m: self.decay * e + (1. - self.decay) * m)
def set(self, model):
self._update(model, update_fn=lambda e, m: m)