wehub-resource-sync
66 lines
1.7 KiB
Python
66 lines
1.7 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.
|
|
|
|
import paddle
|
|
|
|
|
|
class Exponential(paddle.distribution.ExponentialFamily):
|
|
"""mock exponential distribution, which support computing entropy and
|
|
kl use bregman divergence
|
|
"""
|
|
|
|
_mean_carrier_measure = 0
|
|
|
|
def __init__(self, rate):
|
|
self._rate = rate
|
|
super().__init__(batch_shape=rate.shape)
|
|
|
|
@property
|
|
def rate(self):
|
|
return self._rate
|
|
|
|
def entropy(self):
|
|
return 1.0 - paddle.log(self._rate)
|
|
|
|
@property
|
|
def _natural_parameters(self):
|
|
return (-self._rate,)
|
|
|
|
def _log_normalizer(self, x):
|
|
return -paddle.log(-x)
|
|
|
|
|
|
class DummyExpFamily(paddle.distribution.ExponentialFamily):
|
|
"""dummy class extend from exponential family"""
|
|
|
|
def __init__(self, *args):
|
|
pass
|
|
|
|
def entropy(self):
|
|
return 1.0
|
|
|
|
@property
|
|
def _natural_parameters(self):
|
|
return (1.0,)
|
|
|
|
def _log_normalizer(self, x):
|
|
return -paddle.log(-x)
|
|
|
|
|
|
@paddle.distribution.register_kl(Exponential, Exponential)
|
|
def _kl_exponential_exponential(p, q):
|
|
rate_ratio = q.rate / p.rate
|
|
t1 = -rate_ratio.log()
|
|
return t1 + rate_ratio - 1
|