clc
clear all
% trace of matrix
disp('Example 1 - Matrix ops')
disp('Trace of a matrix')
% add all the diagonal elements together
% INPUTS
a=[2 -1 3;4 1 3;5 7 -4];
[r,c]=size(a);
disp('The input matrix is:')
disp(a)
% CODE
if r~=c
    disp('Error - matrix is not square')
else
    trace=0;
    for i=1:1:r
        trace=trace+a(i,i);
    end
    fprintf('The trace is %g\n',trace)
end