Mercurial > octave-nkf
view scripts/image/jet.m @ 14641:5f1d4def40e1
improve compatibility of colormap functions
* autumn.m, bone.m, cool.m, copper.m, flag.m, gmap40.m, gray.m, hot.m,
hsv.m, jet.m, lines.m, ocean.m, pink.m, prism.m, rainbow.m,
spring.m, summer.m, winter: Always size and return 0x3 when size < 1.
Return same values as Matlab when size == 1.
author | Carnë Draug <carandraug+dev@gmail.com> |
---|---|
date | Wed, 16 May 2012 16:52:44 -0400 |
parents | b9c02ee24de1 |
children | 1a800034d443 |
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## Copyright (C) 1999-2012 Kai Habel ## ## This file is part of Octave. ## ## Octave 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. ## ## Octave 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 Octave; see the file COPYING. If not, see ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {@var{map} =} jet () ## @deftypefnx {Function File} {@var{map} =} jet (@var{n}) ## Create color colormap. This colormap ranges from dark blue through blue, ## cyan, green, yellow, red, to dark red. ## The argument @var{n} must be a scalar. ## If unspecified, the length of the current colormap, or 64, is used. ## @seealso{colormap} ## @end deftypefn ## Author: Kai Habel <kai.habel@gmx.de> ## PKG_ADD: colormap ("register", "jet"); ## PKG_DEL: colormap ("unregister", "jet"); function map = jet (n) if (nargin == 0) n = rows (colormap); elseif (nargin == 1) if (! isscalar (n)) error ("jet: argument must be a scalar"); endif else print_usage (); endif if (n == 1) map = [0, 1, 1]; elseif (n > 1) x = linspace (0, 1, n)'; r = (x >= 3/8 & x < 5/8) .* (4 * x - 3/2) ... + (x >= 5/8 & x < 7/8) ... + (x >= 7/8) .* (-4 * x + 9/2); g = (x >= 1/8 & x < 3/8) .* (4 * x - 1/2) ... + (x >= 3/8 & x < 5/8) ... + (x >= 5/8 & x < 7/8) .* (-4 * x + 7/2); b = (x < 1/8) .* (4 * x + 1/2) ... + (x >= 1/8 & x < 3/8) ... + (x >= 3/8 & x < 5/8) .* (-4 * x + 5/2); map = [r, g, b]; else map = zeros (0, 3); endif endfunction %!demo %! ## Show the 'jet' colormap as an image %! image (1:64, linspace (0, 1, 64), repmat ((1:64)', 1, 64)); %! axis ([1, 64, 0, 1], "ticy", "xy"); %! colormap (jet (64));