Mercurial > octave-antonio
view scripts/image/colorcube.m @ 17170:d6499c14021c
doc: Periodic grammarcheck of documentation.
* doc/interpreter/basics.txi, doc/interpreter/expr.txi,
doc/interpreter/install.txi, doc/interpreter/java.txi,
doc/interpreter/plot.txi, doc/interpreter/sparse.txi,
doc/interpreter/vectorize.txi, libinterp/corefcn/cellfun.cc,
libinterp/corefcn/debug.cc, libinterp/corefcn/file-io.cc,
libinterp/corefcn/load-save.cc, libinterp/corefcn/matrix_type.cc,
libinterp/corefcn/pr-output.cc, libinterp/parse-tree/oct-parse.in.yy,
liboctave/numeric/LSODE-opts.in, scripts/image/imformats.m,
scripts/image/imread.m, scripts/image/imwrite.m,
scripts/miscellaneous/error_ids.m, scripts/miscellaneous/fileattrib.m,
scripts/miscellaneous/mex.m, scripts/miscellaneous/mkoctfile.m,
scripts/miscellaneous/warning_ids.m, scripts/prefs/prefdir.m,
scripts/prefs/preferences.m, scripts/signal/fftfilt.m,
scripts/strings/isstrprop.m, scripts/testfun/assert.m:
Periodic grammarcheck of documentation.
author | Rik <rik@octave.org> |
---|---|
date | Sun, 04 Aug 2013 13:08:39 -0700 |
parents | 1a800034d443 |
children | b81b9d079515 |
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## Copyright (C) 2012 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));