Mercurial > hg > octave-nkf

annotate scripts/signal/hamming.m @ 3449:858695b3ed62

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
[project @ 2000-01-18 04:08:59 by jwe]
author jwe
date Tue, 18 Jan 2000 04:09:14 +0000
parents f8dde1807dee
children e031284eea27
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
1 ## Copyright (C) 1995, 1996, 1997 Andreas Weingessel
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
2 ##
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
3 ## This program is free software; you can redistribute it and/or modify
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
4 ## it under the terms of the GNU General Public License as published by
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
5 ## the Free Software Foundation; either version 2, or (at your option)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
6 ## any later version.
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
7 ##
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
8 ## This program is distributed in the hope that it will be useful, but
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
9 ## WITHOUT ANY WARRANTY; without even the implied warranty of
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
11 ## General Public License for more details.
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
12 ##
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
13 ## You should have received a copy of the GNU General Public License
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
14 ## along with this file. If not, write to the Free Software Foundation,
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
15 ## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
16
3449
858695b3ed62 [project @ 2000-01-18 04:08:59 by jwe]
jwe
parents: 3426
diff changeset
17 ## -*- texinfo -*-
858695b3ed62 [project @ 2000-01-18 04:08:59 by jwe]
jwe
parents: 3426
diff changeset
18 ## @deftypefn {Function File} {} hamming (@var{m})
858695b3ed62 [project @ 2000-01-18 04:08:59 by jwe]
jwe
parents: 3426
diff changeset
19 ## Return the filter coefficients of a Hamming window of length @var{m}.
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
20 ##
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
21 ## For a definition of the Hamming window, see e.g. A. V. Oppenheim &
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
22 ## R. W. Schafer, "Discrete-Time Signal Processing".
3449
858695b3ed62 [project @ 2000-01-18 04:08:59 by jwe]
jwe
parents: 3426
diff changeset
23 ## @end deftypefn
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
24
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
25 ## Author: AW <Andreas.Weingessel@ci.tuwien.ac.at>
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
26 ## Description: Coefficients of the Hamming window
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
27
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
28 function c = hamming (m)
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
29
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
30 if (nargin != 1)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
31 usage ("hamming (m)");
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
32 endif
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
33
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
34 if !(is_scalar (m) && (m == round (m)) && (m > 0))
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
35 error ("hamming: m has to be an integer > 0");
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
36 endif
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
37
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
38 if (m == 1)
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
39 c = 1;
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
40 else
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
41 m = m - 1;
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
42 c = 0.54 - 0.46 * cos (2 * pi * (0:m)' / m);
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
43 endif
3426
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe]
jwe
parents: 3191
diff changeset
44
3191
e4f4b2d26ee9 [project @ 1998-10-23 05:43:59 by jwe]
jwe
parents:
diff changeset
45 endfunction