Could someone give me the answer of the following MATLAB code z = [ 1 0 0 1 0 0 0 1 0 0 1 0 0 0 1 0 0 1 ]; z(:, any(z)) = ??? The output of OCTAVE is 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 I don't know if it's correct because I do not have MATLAB here. Thanks in advance, Vu Nguyen-Cong ncv@ap.cc.affrc.go.jp