Hello Stéphane, >De: "Stéphane Mottelet" <stephane.mottelet at utc.fr> >Is it possible to declare a uint8 matrix without first declaring it as a >double ? ../.. Yes, you can do: -->ui = resize_matrix(uint8(0),5,3) ui = 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -->typeof(ui) ans = uint8 Regards Samuel