void rotate2d (double x[], double y[], int pts, double angle);
void xlat2d (double x[], double y[], int pts, double xoffset, double yoffset);
void scale2d (double x[], double y[], int pts, double xfact, double yfact);
void rotate2d (double x[], double y[], int pts, double angle);
void xlat2d (double x[], double y[], int pts, double xoffset, double yoffset);
void scale2d (double x[], double y[], int pts, double xfact, double yfact);