code: public boolean isInSphere(Vector origin, double radius) {
          return (NumberConversions.square(origin.x - x) + NumberConversions.square(origin.y - y) + NumberConversions.square(origin.z - z)) <= NumberConversions.square(radius);
      }
docs: Returns whether this vector is within a sphere.
  
  @param origin Sphere origin.
  @param radius Sphere radius
  @return whether this vector is in the sphere