是否有逆 np.dot 函数? [英] Is there any inverse np.dot function?
问题描述
如果我有两个矩阵 a 和 b,是否有任何函数可以找到矩阵 x,当点乘以 a 时得到 b?寻找python解决方案,用于numpy数组形式的矩阵.
If I have two matrices a and b, is there any function I can find the matrix x, that when dot multiplied by a makes b? Looking for python solutions, for matrices in the form of numpy arrays.
推荐答案
这个求X如A*X=B
的问题等价于搜索A的逆",即一个矩阵如X = Ainverse * B
.
This problem of finding X such as A*X=B
is equivalent to search the "inverse of A", i.e. a matrix such as X = Ainverse * B
.
有关信息,在数学 Ainverse
中注明 A^(-1)
(A 的幂 -1",但您可以说A 逆"; 代替).
For information, in math Ainverse
is noted A^(-1)
("A to the power -1", but you can say "A inverse" instead).
在 numpy 中,这是一个内置函数,用于求矩阵的逆a
:
In numpy, this is a builtin function to find the inverse of a matrix a
:
import numpy as np
ainv = np.linalg.inv(a)
例如参见本教程了解说明.
您需要注意一些矩阵不是可逆的",最明显的例子(大致)是:
You need to be aware that some matrices are not "invertible", most obvious examples (roughly) are:
- 非方阵
- 表示投影的矩阵
numpy 在某些情况下仍然可以近似某个值.
numpy can still approximate some value in certain cases.
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