Transform Cartesian coordinates to polar or cylindrical
[THETA,RHO,Z] = cart2pol(X,Y,Z)
[THETA,RHO] = cart2pol(X,Y)
[THETA,RHO,Z] = cart2pol(X,Y,Z) transforms three-dimensional Cartesian coordinates stored in corresponding elements of arrays X, Y, and Z, into cylindrical coordinates. THETA is a counterclockwise angular displacement in radians from the positive x-axis, RHO is the distance from the origin to a point in the x-y plane, and Z is the height above the x-y plane. Arrays X, Y, and Z must be the same size (or any can be scalar).