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Add demos for colormap functions
author Soren Hauberg <hauberg@gmail.com>
date Thu, 22 Oct 2009 12:18:56 -0400
parents a1dbe9d80eee
children 466ba499eff5
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1 ## Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2005, 2006, 2007
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2 ## John W. Eaton
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3 ##
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4 ## This file is part of Octave.
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5 ##
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6 ## Octave is free software; you can redistribute it and/or modify it
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7 ## under the terms of the GNU General Public License as published by
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8 ## the Free Software Foundation; either version 3 of the License, or (at
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9 ## your option) any later version.
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10 ##
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11 ## Octave is distributed in the hope that it will be useful, but
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12 ## WITHOUT ANY WARRANTY; without even the implied warranty of
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13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 ## General Public License for more details.
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15 ##
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16 ## You should have received a copy of the GNU General Public License
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17 ## along with Octave; see the file COPYING. If not, see
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18 ## <http://www.gnu.org/licenses/>.
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19
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20 ## -*- texinfo -*-
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21 ## @deftypefn {Function File} {} gray (@var{n})
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22 ## Return a gray colormap with @var{n} entries corresponding to values from
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23 ## 0 to @var{n}-1. The argument @var{n} should be a scalar. If it is
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24 ## omitted, the length of the current colormap or 64 is assumed.
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25 ## @end deftypefn
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26
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27 ## Author: Tony Richardson <arichard@stark.cc.oh.us>
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28 ## Created: July 1994
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29 ## Adapted-By: jwe
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31 function map = gray (number)
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33 if (nargin == 0)
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34 number = rows (colormap);
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35 elseif (nargin == 1)
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36 if (! isscalar (number))
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37 error ("gray: argument must be a scalar");
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38 endif
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39 else
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40 print_usage ();
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41 endif
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42
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43 gr = [0:(number-1)]';
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44
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45 map = [ gr, gr, gr ] / (number - 1);
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46
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47 endfunction
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49 %!demo
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50 %! ## Show the 'gray' colormap as an image
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51 %! image (1:64, linspace (0, 1, 64), repmat (1:64, 64, 1)')
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52 %! axis ([1, 64, 0, 1], "ticy", "xy")
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53 %! colormap gray
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