time   calls  line
                  1 function [az,elev,r] = cart2sph(x,y,z)
                  2 %CART2SPH Transform Cartesian to spherical coordinates.
                  3 %   [TH,PHI,R] = CART2SPH(X,Y,Z) transforms corresponding elements of
                  4 %   data stored in Cartesian coordinates X,Y,Z to spherical
                  5 %   coordinates (azimuth TH, elevation PHI, and radius R).  The arrays
                  6 %   X,Y, and Z must be the same size (or any of them can be scalar).
                  7 %   TH and PHI are returned in radians.
                  8 %
                  9 %   TH is the counterclockwise angle in the xy plane measured from the
                 10 %   positive x axis.  PHI is the elevation angle from the xy plane.
                 11 %
                 12 %   Class support for inputs X,Y,Z:
                 13 %      float: double, single
                 14 %
                 15 %   See also CART2POL, SPH2CART, POL2CART.
                 16 
                 17 %   Copyright 1984-2005 The MathWorks, Inc. 
                 18 %   $Revision: 5.12.4.2 $  $Date: 2005/05/31 16:31:21 $
                 19 
  0.19       5   20 hypotxy = hypot(x,y); 
  0.16       5   21 r = hypot(hypotxy,z); 
  0.21       5   22 elev = atan2(z,hypotxy); 
  0.25       5   23 az = atan2(y,x);