Inverse of a matrix in MATLAB and Python

Question

Cool deb 2022-11-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1843453-inverse-of-a-matrix-in-matlab-and-python

移动：KSSV 2022-11-4

Python code:

A= np.array([[1,2,3],[2,3,4],[3,4,5]])
print(np.linalg.inv(A))

MATLAB code:

A = [1,2,3;2,3,4;3,4,5]
inv(A)

Python Output:

[[-4.50359963e+15  9.00719925e+15 -4.50359963e+15]
    [ 9.00719925e+15 -1.80143985e+16  9.00719925e+15]
    [-4.50359963e+15  9.00719925e+15 -4.50359963e+15]]

Matlab Output:

ans =

0e+16 *
3002   -0.6005    0.3002
-0.6005    1.2010   -0.6005
3002   -0.6005    0.3002

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Answer 1

KSSV 2022-11-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1843453-inverse-of-a-matrix-in-matlab-and-python#answer_1091283

You are to trying to fid the inverse of a singular matrix. A singular matrix is the one which doesn't have inverse. So different programming languages, different versions of the same languages might give different answers based on the math library they use.

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KSSV 2022-11-4

移动：KSSV 2022-11-4

在 MATLAB Online 中打开

Note that it is a singular matrix.

A = [1,2,3;2,3,4;3,4,5]
A = 3×3
     1     2     3
     2     3     4
     3     4     5
inv(A)
Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND =  4.625929e-18.
ans = 3×3
1.0e+15 *

   -2.2518    4.5036   -2.2518
    4.5036   -9.0072    4.5036
   -2.2518    4.5036   -2.2518