indexing diagonal elements of a matrix in a loop

I have an n x n matrix, some of its diagonals are zeros. I need to eliminate the rows and columns corresponding to the diagonal zeros in a loop and retain all other elements. ie, if A=[0 3 5 6 5;3 0 4 7 8;7 9 1 0 3;2 4 6 0 8;1 4 5 7 6],after elimination of rows and columns corresponding to diagonal zeros the answer should be, ans=[1 3;5 6]

anyone please help with appropriate code.

Answer 1

[Image Analyst]

Here's one way:

A=[0 3 5 6 5;3 0 4 7 8;7 9 1 0 3;2 4 6 0 8;1 4 5 7 6]

diagonal = logical(eye(size(A)))
% Find bad rows,columns along the diagonal:
badRows = A(diagonal)==0
% Remove rows:
A(badRows, :) = [];
% Remove bad columns:
A(:, badRows) = []

[Image Analyst]

I hope this wasn't homework. Though I didn't use a loop like you were instructed, so I guess it's safe. But you can see the concept of setting the row or column to [] to remove it - that's the main thing you want to remember, though it might be better to build up a separate "B" output matrix as you go along and encounter "good" rows and columns.

[Shince Joseph]

Thanks a lot :)

Answer 2

[Andrei Bobrov]

ii = find(diag(A));
out = A(ii,ii);