Cutting rows and columns from a matrix

If A = [0,0,0,0;0,0,0,0;0,0,1,1;0,0,1,1], how can i cut out the null comumns and rows to acheive B = [1,1;1,1]

Answer 1

[Jos (10584)]

See ANY (or ALL). You need a two step approach:

A = [1 0 1 0 ; 1 0 1 0 ; 0 0 0 0]
B = A(any(A,2),:) ; % remove null rows
B = B(:,any(A,1))  % remove null columns

Answer 2

[Andrei Bobrov]

B = zeros(sum(any(A,2)),sum(any(A)));
B(:)=A(A~=0);