bool between ( double xa, double ya, double xb, double yb, double xc, double yc ); bool collinear ( double xa, double ya, double xb, double yb, double xc, double yc ); bool diagonal ( int im1, int ip1, int n, int prev[], int next[], double x[], double y[] ); bool diagonalie ( int im1, int ip1, int n, int next[], double x[], double y[] ); bool in_cone ( int im1, int ip1, int n, int prev[], int next[], double x[], double y[] ); bool intersect ( double xa, double ya, double xb, double yb, double xc, double yc, double xd, double yd ); bool intersect_prop ( double xa, double ya, double xb, double yb, double xc, double yc, double xd, double yd ); bool l4_xor ( bool l1, bool l2 ); double *monomial_value ( int m, int n, int e[], double x[] ); double polygon_area ( int nv, double v[] ); double polygon_monomial_integral ( int nv, double v[], int e[] ); double *polygon_sample ( int nv, double v[], int n, int &seed ); int *polygon_triangulate ( int n, double x[], double y[] ); double r8_choose ( int n, int k ); double r8_uniform_01 ( int &seed ); double r8vec_sum ( int n, double a[] ); double *r8vec_uniform_01_new ( int n, int &seed ); void timestamp ( ); double triangle_area ( double xa, double ya, double xb, double yb, double xc, double yc );