-
Notifications
You must be signed in to change notification settings - Fork 34
/
_random_normal_like.py
71 lines (60 loc) · 2.85 KB
/
_random_normal_like.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
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
# Copyright 2019 The FastEstimator 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 typing import TypeVar, Union
import numpy as np
import tensorflow as tf
import torch
from fastestimator.util.util import STRING_TO_TORCH_DTYPE
Tensor = TypeVar('Tensor', tf.Tensor, torch.Tensor, np.ndarray)
def random_normal_like(tensor: Tensor, mean: float = 0.0, std: float = 1.0,
dtype: Union[None, str] = 'float32') -> Tensor:
"""Generate noise shaped like `tensor` from a random normal distribution with a given `mean` and `std`.
This method can be used with Numpy data:
```python
n = np.array([[0,1],[2,3]])
b = fe.backend.random_normal_like(n) # [[-0.6, 0.2], [1.9, -0.02]]
b = fe.backend.random_normal_like(n, mean=5.0) # [[3.7, 5.7], [5.6, 3.6]]
```
This method can be used with TensorFlow tensors:
```python
t = tf.constant([[0,1],[2,3]])
b = fe.backend.random_normal_like(t) # [[-0.6, 0.2], [1.9, -0.02]]
b = fe.backend.random_normal_like(t, mean=5.0) # [[3.7, 5.7], [5.6, 3.6]]
```
This method can be used with PyTorch tensors:
```python
p = torch.tensor([[0,1],[2,3]])
b = fe.backend.random_normal_like(p) # [[-0.6, 0.2], [1.9, -0.02]]
b = fe.backend.random_normal_like(P, mean=5.0) # [[3.7, 5.7], [5.6, 3.6]]
```
Args:
tensor: The tensor whose shape will be copied.
mean: The mean of the normal distribution to be sampled.
std: The standard deviation of the normal distribution to be sampled.
dtype: The data type to be used when generating the resulting tensor. This should be one of the floating point
types.
Returns:
A tensor of random normal noise with the same shape as `tensor`.
Raises:
ValueError: If `tensor` is an unacceptable data type.
"""
if tf.is_tensor(tensor):
return tf.random.normal(shape=tensor.shape, mean=mean, stddev=std, dtype=dtype)
elif isinstance(tensor, torch.Tensor):
return torch.randn_like(tensor, dtype=STRING_TO_TORCH_DTYPE[dtype]) * std + mean
elif isinstance(tensor, np.ndarray):
return np.random.normal(loc=mean, scale=std, size=tensor.shape).astype(dtype=dtype)
else:
raise ValueError("Unrecognized tensor type {}".format(type(tensor)))