Two-center bipolar coordinates
In mathematics, two-center bipolar coordinates is a coordinate system, based on two coordinates which give distances from two fixed centers, and. This system is very useful in some scientific applications.The transformation to Cartesian coordinates from two-center bipolar coordinates is
where the centers of this coordinate system are at and.When x>0 the transformation to polar coordinates from two-center bipolar coordinates is
where is the distance between the poles.