how to create an anti-identity matrix in matlab

In Matlab, an anti-identity matrix is simply a matrix with -1 on the diagonal and zeros elsewhere. Here's an example code to create a 5 x 5 anti-identity matrix:

main.m
n = 5;
A = zeros(n); % create a matrix of zeros
A(1:n+1:end) = -1; % set the diagonal elements to -1
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Let's break down the code step by step.

• n is the size of the matrix. We've set it to 5 for this example.
• A = zeros(n) creates a n x n matrix of zeros.
• A(1:n+1:end) = -1 sets the diagonal elements of A to -1. The 1:n+1:end notation is a shorthand for selecting every n+1th element in the matrix starting at the first element. Since the diagonal of A starts at the first element and has n+1 elements between successive diagonal elements, this notation selects all the diagonal elements.

With these three lines of code, we have created a 5 x 5 anti-identity matrix in Matlab.