Verify a matrix value on MATLAB

Question

I am using MATLAB. I have a question about how i can verify that the values of a matrix are being repeating, like this:

A=[ 2 3 2 3 2 3 2 3]

If

Answer 1

The following one-liner works if A is a row or column vector, but not necessarily if it is a matrix (thanks to @Dan for providing a simplification in comments). I figured this would be okay since the example you provide in the question is a vector.

AUX = ~any(A(3:end) - A(1:end-2))

This vectorized solution should be a lot faster than the non-vectorized solution supplied by @Nirk (for large A).

Depending on your application you may need to include the error trap:

if size(A, 2) < 3; error('Input matrix needs to have at least 3 columns'); end

Note, see the comments on this answer for some alternative ways of dealing with the case size(A, 2) < 3.