ccxyz.m

%CCXYZ XYZ chromaticity coordinates
%
% XYZ = CCXYZ(LAMBDA) is the xyz-chromaticity coordinates (3x1) for
% illumination at wavelength LAMBDA.  If LAMBDA is a vector (Nx1) then each
% row of XYZ (Nx3) is the XYZ-chromaticity of the corresponding element of
% LAMBDA.
%
% XYZ = CCXYZ(LAMBDA, E) is the xyz-chromaticity coordinates (Nx3) for an
% illumination spectrum E (Nx1) defined at corresponding wavelengths LAMBDA
% (Nx1).
%
% References::
%  - Robotics, Vision & Control, Section 10.2,
%    P. Corke, Springer 2011.
%
% See also CMFXYZ.

% Copyright 2022-2023 Peter Corke, Witold Jachimczyk, Remo Pillat

function [x,y] = ccxyz(lambda, e)
    xyz = cmfxyz(lambda);
    if nargin == 1
        cc = xyz ./ (sum(xyz')'*ones(1,3));
    elseif nargin == 2
        xyz = xyz .* (e(:)*ones(1,3));
        xyz = sum(xyz);
        cc = xyz ./ (sum(xyz')'*ones(1,3));
    end

    if nargout == 1
        x = cc;
    elseif nargout == 2
        x = cc(:,1);
        y = cc(:,2);
    end
end