Mercurial > octave-nkf
view scripts/image/colorcube.m @ 19647:e8e3a89fa370
Fix colormap functions when N is not of class double (bug #44070)
* autumn.m, bone.m, cool.m, copper.m, cubehelix.m, gray.m, hsv.m, ocean.m,
rainbow.m, spring.m, summer.m, winter.m: cast N to double since in this
colormap functions, N is used directly used in the operations and ends up
casting colormap to something else. Note that a colormap MUST be of class
double. Also, if N is an integer class, all values in colormap end up 0
or 1. Also simplify code for input checking by declaring default on function
signature line.
* flag.m, gmap40.m, hot.m, jet.m, lines.m, pink.m, prism.m, white.m: simplify
input check like the other colormap functions.
* test/colormaps.tst: add new test file to test all colormaps at once.
* test/Makefile.am: add new test file to build system.
used to create the colormap and if less
author | Carnë Draug <carandraug@octave.org> |
---|---|
date | Fri, 23 Jan 2015 15:37:56 +0000 |
parents | 446c46af4b42 |
children | 4197fc428c7d |
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## Copyright (C) 2012-2013 Rik Wehbring ## ## 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} =} colorcube () ## @deftypefnx {Function File} {@var{map} =} colorcube (@var{n}) ## Create color colormap. This colormap is composed of as many equally ## spaced colors (not grays) in the RGB color space as possible. If there ## are not a perfect number @var{n} of regularly spaced colors then the ## remaining entries in the colormap are gradients of pure red, green, blue, ## and gray. ## The argument @var{n} must be a scalar. ## If unspecified, the length of the current colormap, or 64, is used. ## @seealso{colormap} ## @end deftypefn function map = colorcube (n) if (nargin == 0) n = rows (colormap); elseif (nargin == 1) if (! isscalar (n)) error ("colorcube: N must be a scalar"); endif else print_usage (); endif if (n < 9) map = gray (n); return; endif ## Create colorcube of evenly spaced points with side length of n^1/3 cubelen = fix (cbrt (n)); reserve = n - cubelen^3; if (reserve == 0) ## Steal space from blue to put the gray gradient [r, g, b] = meshgrid (linspace (0,1,cubelen), linspace (0,1,cubelen), linspace (0,1,cubelen-1)); else [r, g, b] = meshgrid (linspace (0,1,cubelen), linspace (0,1,cubelen), linspace (0,1,cubelen)); endif ## Create map and weed out grays map = [r(:), g(:), b(:)]; idx = any (bsxfun (@ne, map(:, 1), map(:, 2:3)), 2); map = map(idx, :); ## Weed out pure colors idx = sum (map == 0, 2); map = map(idx != 2, :); ## Put in remaining gradients of pure red, green, blue, and gray reserve = n - rows (map) - 1; csteps = fix (reserve/4); cstepsz = 1 / csteps; cgrad = (cstepsz:cstepsz:1)'; gsteps = reserve - 3*csteps; gstepsz = 1 / gsteps; ggrad = (gstepsz:gstepsz:1)'; map = [map cgrad, zeros(csteps, 1), zeros(csteps, 1) zeros(csteps, 1), cgrad, zeros(csteps, 1) zeros(csteps, 1), zeros(csteps, 1), cgrad 0, 0, 0 ggrad, ggrad, ggrad]; endfunction %!demo %! ## Show the 'colorcube' colormap as an image %! image (1:64, linspace (0, 1, 64), repmat ((1:64)', 1, 64)); %! axis ([1, 64, 0, 1], "ticy", "xy"); %! colormap (colorcube (64));