%% Copyright (C) 1999,2000  Kai Habel
%%
%% This program is free software; you can redistribute it and/or modify
%% it under the terms of the GNU General Public License as published by
%% the Free Software Foundation; either version 3 of the License, or
%% (at your option) any later version.
%%
%% This program is distributed in the hope that it will be useful,
%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%% GNU General Public License for more details.
%%
%% You should have received a copy of the GNU General Public License
%% along with this program; if not, write to the Free Software
%% Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA

%% -*- texinfo -*-
%% @deftypefn {Function File} {} cool (@var{n})
%% Create color colormap.
%% (cyan to magenta)
%% The argument @var{n} should be a scalar.  If it
%% is omitted, the length of the current colormap or 64 is assumed.
%% @end deftypefn
%% @seealso{colormap}

%% Author:  Kai Habel <kai.habel@gmx.de>

function map = cool (number)

  if (nargin == 0)
    number = rows (colormap);
  elseif (nargin == 1)
    if (! is_scalar (number))
      error ("cool: argument must be a scalar");
    end
  else
    usage ("cool (number)");
  end

  if (number == 1)
    map = [0, 1, 1];
  elseif (number > 1)
    r = (0:number - 1)' ./ (number - 1);
    g = 1 - r;
    b = ones (number, 1);
    map = [r, g, b];
  else
    map = [];
  end