"Emrah " <firstname.lastname@example.org> wrote in message <email@example.com>... > > thank you very much. now, i cant get different results while i change the values of constants :) > > but it gave me a flat shape. is this because of the function? =================
Forget my last message. It's flat because, with x(1) and x(4) fixed, f(x) reduces to the formula for a plane.