PostGIS  2.4.9dev-r@@SVN_REVISION@@

## ◆ vector_angle()

 double vector_angle ( const POINT3D * v1, const POINT3D * v2 )

Angle between two unit vectors.

Definition at line 501 of file lwgeodetic.c.

References cross_product(), dot_product(), normalize(), pixval::x, and pixval::y.

Referenced by test_vector_angle().

502 {
503  POINT3D v3, normal;
504  double angle, x, y;
505
506  cross_product(v1, v2, &normal);
507  normalize(&normal);
508  cross_product(&normal, v1, &v3);
509
510  x = dot_product(v1, v2);
511  y = dot_product(v2, &v3);
512
513  angle = atan2(y, x);
514  return angle;
515 }
void normalize(POINT3D *p)
Normalize to a unit vector.
Definition: lwgeodetic.c:611
static double dot_product(const POINT3D *p1, const POINT3D *p2)
Convert cartesion coordinates on unit sphere to lon/lat coordinates static void cart2ll(const POINT3D...
Definition: lwgeodetic.c:442
static void cross_product(const POINT3D *a, const POINT3D *b, POINT3D *n)
Calculate the cross product of two vectors.
Definition: lwgeodetic.c:450
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