Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/tensorflow_addons/activations/snake.py: 57%

1# Copyright 2020 The TensorFlow Authors. All Rights Reserved. 

2# 

3# Licensed under the Apache License, Version 2.0 (the "License"); 

4# you may not use this file except in compliance with the License. 

5# You may obtain a copy of the License at 

6# 

7# http://www.apache.org/licenses/LICENSE-2.0 

8# 

9# Unless required by applicable law or agreed to in writing, software 

10# distributed under the License is distributed on an "AS IS" BASIS, 

11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

12# See the License for the specific language governing permissions and 

13# limitations under the License. 

14# ============================================================================== 

15 

16import tensorflow as tf 

17 

18from tensorflow_addons.utils import types 

19 

20 

21@tf.keras.utils.register_keras_serializable(package="Addons") 

22def snake(x: types.TensorLike, frequency: types.Number = 1) -> tf.Tensor: 

23 r"""Snake activation to learn periodic functions. 

24 

25 Computes snake activation: 

26 

27 $$ 

28 \mathrm{snake}(x) = \mathrm{x} + \frac{1 - \cos(2 \cdot \mathrm{frequency} \cdot x)}{2 \cdot \mathrm{frequency}}. 

29 $$ 

30 

31 See [Neural Networks Fail to Learn Periodic Functions and How to Fix It](https://arxiv.org/abs/2006.08195). 

32 

33 Usage: 

34 

35 >>> x = tf.constant([-1.0, 0.0, 1.0]) 

36 >>> tfa.activations.snake(x) 

37 <tf.Tensor: shape=(3,), dtype=float32, numpy=array([-0.29192656, 0. , 1.7080734 ], dtype=float32)> 

38 

39 Args: 

40 x: A `Tensor`. 

41 frequency: A scalar, frequency of the periodic part. 

42 Returns: 

43 A `Tensor`. Has the same type as `x`. 

44 """ 

45 x = tf.convert_to_tensor(x) 

46 frequency = tf.cast(frequency, x.dtype) 

47 

48 return x + (1 - tf.cos(2 * frequency * x)) / (2 * frequency)