1 ## Copyright (C) 1999-2012 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} {} hsv (@var{n})
21 ## Create color colormap. This colormap begins with red, changes through
22 ## yellow, green, cyan, blue, and magenta, before returning to red.
23 ## It is useful for displaying periodic functions. It is obtained by linearly
24 ## varying the hue through all possible values while keeping constant maximum
25 ## saturation and value and is equivalent to
26 ## @code{hsv2rgb ([linspace(0,1,N)', ones(N,2)])}.
28 ## The argument @var{n} must be a scalar.
29 ## If unspecified, the length of the current colormap, or 64, is used.
33 ## Author: Kai Habel <kai.habel@gmx.de>
35 function map = hsv (n)
41 error ("hsv: argument must be a scalar");
50 h = linspace (0, 1, n)';
51 map = hsv2rgb ([h, ones(n, 1), ones(n, 1)]);
59 %! ## Show the 'hsv' colormap as an image
60 %! image (1:64, linspace (0, 1, 64), repmat (1:64, 64, 1)')
61 %! axis ([1, 64, 0, 1], "ticy", "xy")
62 %! colormap (hsv (64))