#!/usr/bin/env python
# ******************************************************************************
# Copyright 2021 Brainchip Holdings Ltd.
#
# 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
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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"""
Custom tf.keras.constraint.Constraint object to limit weights minimum value.
"""
import tensorflow as tf
from keras.constraints import Constraint
[docs]
class MinValueConstraint(Constraint):
""" Constraint that ensures that weights values are not below a minimum
value.
Args:
min_value: the minimum desired value for the weights
"""
def __init__(self, min_value=1e-2):
self.min_value = min_value
def __call__(self, w):
return tf.clip_by_value(w, self.min_value, tf.float32.max)
def get_config(self):
config = super().get_config()
config.update({'min_value': self.min_value})
return config