1 ## Copyright (C) 2000-2012 Kai Habel
3 ## This file is part of Octave.
5 ## Octave is free software; you can redistribute it and/or modify it
6 ## under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 3 of the License, or (at
8 ## your option) any later version.
10 ## Octave is distributed in the hope that it will be useful, but
11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 ## General Public License for more details.
15 ## You should have received a copy of the GNU General Public License
16 ## along with Octave; see the file COPYING. If not, see
17 ## <http://www.gnu.org/licenses/>.
20 ## @deftypefn {Function File} {@var{map} =} pink ()
21 ## @deftypefnx {Function File} {@var{map} =} pink (@var{n})
22 ## Create color colormap. This colormap varies from black to white with
23 ## shades of gray-pink. It gives a sepia tone when used on grayscale images.
24 ## The argument @var{n} must be a scalar.
25 ## If unspecified, the length of the current colormap, or 64, is used.
29 ## Author: Kai Habel <kai.habel@gmx.de>
31 function map = pink (n)
37 error ("pink: argument must be a scalar");
46 x = linspace (0, 1, n)';
47 r = (x < 3/8) .* (14/9 * x) + (x >= 3/8) .* (2/3 * x + 1/3);
48 g = (x < 3/8) .* (2/3 * x)\
49 + (x >= 3/8 & x < 3/4) .* (14/9 * x - 1/3)\
50 + (x >= 3/4) .* (2/3 * x + 1/3);
51 b = (x < 3/4) .* (2/3 * x) + (x >= 3/4) .* (2 * x - 1);
53 map = sqrt ([r, g, b]);
61 %! ## Show the 'pink' colormap as an image
62 %! image (1:64, linspace (0, 1, 64), repmat (1:64, 64, 1)')
63 %! axis ([1, 64, 0, 1], "ticy", "xy")
64 %! colormap (pink (64))