public SphericalPolarCoordinates(Vector3D v,double newRadius){
  radius=v.modulus();
  theta=Math.acos(v.getZ() / radius);
  phi=Math.atan(v.getY() / v.getX());
  if (v.getY() < 0)   phi+=Math.PI;
  radius=newRadius;
}

public SphericalPolarCoordinates ( Vector3D v , double newRadius ) { radius = v . modulus ( ) ; theta = Math . acos ( v . getZ ( ) / radius ) ; phi = Math . atan ( v . getY ( ) / v . getX ( ) ) ; if ( v . getY ( ) < 0 ) phi += Math . PI ; radius = newRadius ; }
create spherical polar coordinates from the given vector
