function varargout = cart2sph2(varargin)
%CART2SPH2 Convert cartesian coordinates to spherical coordinates.
%
%   [THETA PHI RHO] = cart2sph2([X Y Z])
%   [THETA PHI RHO] = cart2sph2(X, Y, Z)
%
%   The following convention is used:
%   THETA is the colatitude, in radians, 0 for north pole, +pi for south
%   pole, pi/2 for points with z=0. 
%   PHI is the azimuth, in radians, defined as matlab cart2sph: angle from
%   Ox axis, counted counter-clockwise.
%   RHO is the distance of the point to the origin.
%   Discussion on choice for convention can be found at:
%   http://www.physics.oregonstate.edu/bridge/papers/spherical.pdf
%
%   Example:
%   cart2sph2([1 0 0])  returns [pi/2 0 1];
%   cart2sph2([1 1 0])  returns [pi/2 pi/4 sqrt(2)];
%   cart2sph2([0 0 1])  returns [0 0 1];
%
%   See also 
%     angles3d, sph2cart2, cart2sph, cart2sph2d
%

% ------
% Author: David Legland 
% E-mail: david.legland@inrae.fr
% Created: 2005-02-18
% Copyright 2005-2022 INRA - TPV URPOI - BIA IMASTE

% parse input angles based on input argument number
if length(varargin) == 1
    xyz = varargin{1};
elseif length(varargin) == 3
    xyz = [varargin{1} varargin{2} varargin{3}];
end

% ensure z coordinate is specified
if size(xyz, 2) == 2
    xyz(:,3) = 1;
end

% convert to spherical coordinates
[p, t, r] = cart2sph(xyz(:,1), xyz(:,2), xyz(:,3));

% format output arguments
if nargout == 1 || nargout == 0
    varargout{1} = [pi/2-t p r];
elseif nargout==2
    varargout{1} = pi/2-t;
    varargout{2} = p;
else
    varargout{1} = pi/2-t;
    varargout{2} = p;
    varargout{3} = r;
end
    
