[tutorial][python] Determinant matrix

It’s for help us to found out inverse of a matrix. syntax like this


And matrix to use determinant MUST BE square (i.e. have the same number of rows as columns).

You better if have a look of this link:
https://www.mathsisfun.com/algebra/matrix-determinant.html

Example 1

Using determinant to calculate this matrix :

We use this rule to multiply elements in matrix where Blue is positive (+ad) and Red is negative (−bc) :


With python, we can use det() method to get the result.

import numpy as np
from scipy import linalg as la

A = np.array([[3,8],[4,6]])
print(la.det(A))

Result :

-14.0

Example 2

det(A) = | A | = (1*4)-(2*3) = 4 - 6  = - 2.0

Calculation with python :

import numpy as np
from scipy import linalg as la

A = np.array([[1,2],[3,4]])
print(A)
B = la.det(A)
print(B)

Result :

[[1 2]
 [3 4]]
-2.0

Example 3

Let use python with package numpy and linalg to represent the determinant of this 3×3 matrix:

import numpy as np
from scipy import linalg as la

A = np.array([[6,1,1],[4,-2,5],[2,8,7]])
print(A)
B = la.det(A)
print(B)

Result: 

[[ 6  1  1]
 [ 4 -2  5]
 [ 2  8  7]]
-306.0