Mercurial > hg > octave-lyh
diff scripts/signal/hamming.m @ 3191:e4f4b2d26ee9
[project @ 1998-10-23 05:43:59 by jwe]
author | jwe |
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date | Fri, 23 Oct 1998 05:44:01 +0000 |
parents | |
children | f8dde1807dee |
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new file mode 100644 --- /dev/null +++ b/scripts/signal/hamming.m @@ -0,0 +1,44 @@ +## Copyright (C) 1995, 1996, 1997 Andreas Weingessel +## +## This program 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 2, or (at your option) +## any later version. +## +## This program 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 this file. If not, write to the Free Software Foundation, +## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +## usage: hamming (m) +## +## Returns the filter coefficients of a Hamming window of length m. +## +## For a definition of the Hamming window, see e.g. A. V. Oppenheim & +## R. W. Schafer, "Discrete-Time Signal Processing". + +## Author: AW <Andreas.Weingessel@ci.tuwien.ac.at> +## Description: Coefficients of the Hamming window + +function c = hamming (m) + + if (nargin != 1) + usage ("hamming (m)"); + endif + + if !(is_scalar (m) && (m == round (m)) && (m > 0)) + error ("hamming: m has to be an integer > 0"); + endif + + if (m == 1) + c = 1; + else + m = m - 1; + c = 0.54 - 0.46 * cos (2 * pi * (0:m)' / m); + endif + +endfunction