someone correct me if i am wrong, but is there really no way of multiplying two matrices, or a matrix and a vector with gsl i know i can go element by element, but i'm looking for something of the form: return_matrix = gsl_matrix_mul_matrix_by_matrix ( matrix_one , matrix_two ); thanks! matt -- Matthew J. Doller mdoller@wpi.edu http://www.wpi.edu/~mdoller