// create a 3rd order polynomial surface
// create a 3rd order polynomial surface
cubic
{
<
// x^3,        x^2y,       x^2z,       x^2,
   0,          0,          0,          0,
// xy^2,       xyz,        xy,         xz^2,
   0,          0,          0,          0,
// xz,         x,          y^3,        y^2z,
   0,          0,          0,          0,
// y^2,        yz^2,       yz,         y,
   0,          0,          0,          0,
// z^3,        z^2,        z,          C
   0,          0,          0,          0
> sturm
}