FilesExpand file tree

Write-for-current-Python

/

sigmoid.py

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

39 lines (27 loc) · 944 Bytes

Write-for-current-Python

/

sigmoid.py

Copy path

Top

File metadata and controls

• Code
• Blame

39 lines (27 loc) · 944 Bytes

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

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

"""

This script demonstrates the implementation of the Sigmoid function.

The function takes a vector of K real numbers as input and then 1 / (1 + exp(-x)).

After through Sigmoid, the element of the vector mostly 0 between 1. or 1 between -1.

Script inspired from its corresponding Wikipedia article

https://en.wikipedia.org/wiki/Sigmoid_function

"""

import numpy as np

def sigmoid(vector: np.array) -> np.array:

"""

Implements the sigmoid function

Parameters:

vector (np.array): A numpy array of shape (1,n)

consisting of real values

Returns:

sigmoid_vec (np.array): The input numpy array, after applying

sigmoid.

Examples:

>>> sigmoid(np.array([-1.0, 1.0, 2.0]))

array([0.26894142, 0.73105858, 0.88079708])

>>> sigmoid(np.array([0.0]))

array([0.5])

"""

return 1 / (1 + np.exp(-vector))

if __name__ == "__main__":

import doctest

doctest.testmod()