function J = lcmap(m,hue)
% function J = lcmap(m,hue)
% 
% Linear Color Map
%   LCMAP(M) is an M-by-3 matrix
%   Saturation linearly ramped from 0 to 1
%   Intensity linearly ramped from 0.2 to 1  (black is too low for
%   details...perhaps on better screens)
%   Hue is constant
%   LCMAP, by itself, is the same length as the current figure's
%   colormap.
%
% optional second input "hue" is scalar color value.  Hue is cyclical about
% (0,1) w/ red at bounds  
%
% Following IBM research on human color perception:
% Why Should Engineers and Scientists Be Worried About Color?
% http://www.research.ibm.com/people/l/lloydt/color/color.HTM
%
% T.Hilmer UH
% 2010.03.14  version 1

if nargin < 1 || isempty(m)
   m = size(get(gcf,'colormap'),1);
end
if nargin < 2
    hue = 1/3; % a nice blue color
else
    if 0 > hue || hue > 1
        warning('second input "hue" outside (0,1) will give black')
    end
end

J = zeros(m,3);

% HSV ramps:
J(:,1) = hue; % HUE
J(:,2) = linspace(0.25,1,m); % SATURATION
J(:,3) = fliplr(linspace(0.5,1,m)); % INTENSITY

J = hsv2rgb(J);