Hi Sorry if this is an obvious question, but I'm getting close to loosing sleep over it now :) If I have a matrix: 1 2 3 4 5 6 7 8 9 is there a nice general way to expand the matrix to: 1 0 2 3 4 0 5 6 0 0 0 0 7 0 8 9 The actual dataset in question has dimensions 128 * 128 * 128; so big enough for me to worry quite abit about duplication and general speed. vennlig hilsen / regards Reidar Strand Hagen