code: @Pure
  	public static boolean containsSpherePoint(double cx, double cy, double cz, double radius,
  			double px, double py, double pz) {
  		return FunctionalPoint3D.distanceSquaredPointPoint(
  				px, py, pz,
  				cx, cy, cz) <= (radius * radius);
  	}
docs: Replies if the given point is inside the given sphere.
  
  @param cx is the center of the sphere.
  @param cy is the center of the sphere.
  @param cz is the center of the sphere.
  @param radius is the radius of the sphere.
  @param px is the point to test.
  @param py is the point to test.
  @param pz is the point to test.
  @return <code>true</code> if the point is inside the circle;
  <code>false</code> if not.