Function robust_geo::in_sphere

pub fn in_sphere(
    a: Vector3<f64>, 
    b: Vector3<f64>, 
    c: Vector3<f64>, 
    d: Vector3<f64>, 
    e: Vector3<f64>
) -> f64

Returns a positive number if e is inside the oriented sphere that goes through a, b, c, d, a negative number if it lies outside, and 0 if a, b, c, d, e are cospherical or a, b, c, d are coplanar. If a, b, c, d are oriented positive, "inside the sphere" is the inside. If a, b, c, d are oriented negative, "inside the sphere" is the outside.