"Mark L. J." <firstname.lastname@example.org> wrote in message <email@example.com>... > ??? Error using ==> mtimes > Inner matrix dimensions must agree. > Error in ==> triscastdmeshgrid10012013b at 6 > F=1.10471*X.^2*A+0.04811*B*(14 + A); - - - - - - - - - It's almost the same problem. You can't do matrix multiplication of two 100 x 1 vectors and that is what "*" without the dot calls for. Use ".*" instead for multiplying element by element.