How to Delete Diagonal Elements from a Matrix and Reshape It?

Hi all,

I have a matrix M that I would like to remove diagonal entries from and reshape it. For reference, all diagonal elements that I want to remove are 1s and the dimensions of this matrix are N x N (where N can be as large as 90) so I will give an smaller example below:

For some of my data, however, the diagonal entries are occasionally NaN. The diagonal entires thus, will either be 1 or NaN.

Thanks

M = [ 1  4  2   3
      5  1  2   3
      3  3  NaN 3
      4  5  3   1 ]

% Ideal New Matrix after

M2 = [ 5  4  2  3
       3  3  2  3
       4  5  3  3  ]

Answer 1

[David Hill]

a=size(M,1);
M(1:a+1:end)=[];
B=reshape(M,a-1,[]);

[Dominique Mutombo]

Thanks for the codes ...