Python Numpy.linalg.inv() - Inverse Matrix

Jinku Hu Jan 30, 2023 May 31, 2020 NumPy
  1. Syntax of numpy.linalg.inv()
  2. Example Codes: numpy.linalg.inv() Method
  3. Example Codes: numpy.linalg.inv() Method With matrix Input
  4. Example Codes: numpy.linalg.inv() With matrix Array
Python Numpy.linalg.inv() - Inverse Matrix

Numpy.linalg.inv() computes the inverse of the given matrix.

Syntax of numpy.linalg.inv()

numpy.linalg.inverse(arr) 

Parameters

arr input array

Return

It returns the inverse of the given matrix.

It raises the error if the given matrix is not square or inversion fails.

Example Codes: numpy.linalg.inv() Method

import numpy as np

arr = np.array([[1, 3], [5, 7]])

arr_inv = np.linalg.inv(arr)

print(arr_inv)

Output:

[[-0.875  0.375]
 [ 0.625 -0.125]]

Example Codes: numpy.linalg.inv() Method With matrix Input

If the given input is a numpy matrix, then inv() also returns a matrix.

import numpy as np

arr = np.matrix([[1, 3], [5, 7]])

arr_inv = np.linalg.inv(arr)

print(arr_inv, type(arr_inv))

Output:

[[-0.875  0.375]
 [ 0.625 -0.125]] <class 'numpy.matrix'>

Example Codes: numpy.linalg.inv() With matrix Array

import numpy as np

arr = np.array([
                [[1, 3],
                 [5, 7]],
                [[2, 5],
                 [4, 6]]])

arr_inv = np.linalg.inv(arr)

print(arr_inv)

Output:

[[[-0.875  0.375]
  [ 0.625 -0.125]]

 [[-0.75   0.625]
  [ 0.5   -0.25 ]]]

If the input array consists of multiple matrices, the numpy linalg.inv() method computes the inverse of them at once.

Author: Jinku Hu
Jinku Hu avatar Jinku Hu avatar

Founder of DelftStack.com. Jinku has worked in the robotics and automotive industries for over 8 years. He sharpened his coding skills when he needed to do the automatic testing, data collection from remote servers and report creation from the endurance test. He is from an electrical/electronics engineering background but has expanded his interest to embedded electronics, embedded programming and front-/back-end programming.

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