On Mon, Jun 01, 2009 at 10:21:22PM +0000, Carlo Rossi wrote: > Hello, > I have a matrix A and I need to do it: > > sum1 = SUM_of_all_element_on_diagonal trace(A) > sum2 = sum_ofAllElemetNonOn_theDiagonal; sum(sum(A)) - trace(A) HTH Oli