Mercurial > octave
view scripts/image/colorcube.m @ 31237:e3016248ca5d
uifigure.m: Call set () only if varargin is not empty (bug #63088)
* uifigure.m: Call set () only if varargin is not empty.
author | John Donoghue <john.donoghue@ieee.org> |
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date | Wed, 21 Sep 2022 09:55:32 -0400 |
parents | 796f54d4ddbf |
children | 597f3ee61a48 |
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######################################################################## ## ## Copyright (C) 2012-2022 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## 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 ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {@var{map} =} colorcube () ## @deftypefnx {} {@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 (! isscalar (n)) error ("colorcube: N must be a scalar"); 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], "xy"); %! set (gca, "xtick", []); %! colormap (colorcube (64));