How can I generate reciprocal of a matrix

I have big matrix A 500 by 500 and I want to generate reciprocal of matrix A

what caluclation shuould I do or is there a function in matlab that I can use

%Matrix A
A = [2, 3, -1, 5; -1, 4, -7, -3; -6, 0, 3, 9; 7, 6, -3, 8];

%Matrix X, reciprocal of matrix A 
X= ....

Answer 1

[Star Strider]

It depends on what you mean by ‘reciprocal’. If you want ‘X’ such that:

A*X = eye(size(A,1))

then:

X1 = inv(A);                                                    % Inverse
X2 = pinv(A);                                                   % Pseudo-Inverse

will do what you want.

There are many precautions about calculating the inverse that you will likely encounter. A much better option would be to use the mldivide,\ (link) function if you want to solve linear systems, for example.

Answer 2

[Walter Roberson]

I suspect that you want inv(A) but possibly you want 1./A

In most cases inv() is better avoided in favor of using the \ operator or decomposition

[S Prudhvi]

Yes I want every element reciprocal in the matrix

[Walter Roberson]

1./A is element-by-element reciprocal.