I have a A ,15*15 matrice with random numbers , i wanna just get the values outside A (5:8 ,5:8) ,I mean A-A(5:8,5:8)?? i know subtract is not possible , becuase dimension is not same , how can i do this?

I have a A ,15*15 matrice with random numbers , i wanna just get the values outside A (5:8 ,5:8) ,I mean A-A(5:8,5:8)?? i know subtract is not possible , becuase dimension is not same , how can i do this?

Answer 1

[Image Analyst]

Try this:

A = randi(9, [15,15]); % Initial data
% Set middle rectangle to nans
A(5:8,5:8) = nan
% Extract numbers not in the NAN rectangle
output = A(~isnan(A))