How to create a constant matrix in python with numpy ?


Examples of how to create a constant matrix in python with numpy:

Constant matrix

To create for example a constant matrix of size (2,2) with a constant 4.2 a solution is to use numpy.full

import numpy as np

A = np.full((2, 2), 4.2)

returns

[[4.2 4.2]
 [4.2 4.2]]

Another example with size (3,3) and an integer 12:

A = np.full((3, 3), 12)

returns

[[12 12 12]
 [12 12 12]
 [12 12 12]]

Matrice of ones

To generate a matrix of ones there is numpy.ones

A = np.ones((2,2), dtype=np.uint8)

returns

[[1. 1.]
 [1. 1.]]

Note: it is possible to specify the type numpy data types:

A = np.ones((2,2), dtype=np.uint8)

returns

[[1 1]
 [1 1]]

Matrice of zeros

To generate a matrix of zeros there is numpy.zeros

A = np.zeros((2,2))

returns

[[0. 0.]
 [0. 0.]]

References