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annotate scripts/signal/hamming.m @ 8920:eb63fbe60fab

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update copyright notices
author John W. Eaton <jwe@octave.org>
date Sat, 07 Mar 2009 10:41:27 -0500
parents 895d49a7e36a
children 1bf0ce0930be
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eb63fbe60fab update copyright notices
John W. Eaton <jwe@octave.org>
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1 ## Copyright (C) 1995, 1996, 1997, 1998, 2000, 2002, 2005, 2006, 2007, 2009
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2 ## Andreas Weingessel
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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} {} hamming (@var{m})
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22 ## Return the filter coefficients of a Hamming window of length @var{m}.
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23 ##
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24 ## For a definition of the Hamming window, see e.g. A. V. Oppenheim &
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Brian Gough <bjg@gnu.org>
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25 ## R. W. Schafer, @cite{Discrete-Time Signal Processing}.
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26 ## @end deftypefn
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27
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28 ## Author: AW <Andreas.Weingessel@ci.tuwien.ac.at>
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29 ## Description: Coefficients of the Hamming window
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30
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31 function c = hamming (m)
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32
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33 if (nargin != 1)
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34 print_usage ();
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35 endif
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36
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37 if (! (isscalar (m) && (m == round (m)) && (m > 0)))
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38 error ("hamming: m has to be an integer > 0");
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39 endif
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40
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41 if (m == 1)
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42 c = 1;
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43 else
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44 m = m - 1;
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45 c = 0.54 - 0.46 * cos (2 * pi * (0:m)' / m);
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46 endif
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47
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48 endfunction