3191
|
1 ## Copyright (C) 1995, 1996, 1997 Friedrich Leisch |
3426
|
2 ## |
3922
|
3 ## This file is part of Octave. |
|
4 ## |
|
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 |
3191
|
7 ## the Free Software Foundation; either version 2, or (at your option) |
|
8 ## any later version. |
3426
|
9 ## |
3922
|
10 ## Octave is distributed in the hope that it will be useful, but |
3191
|
11 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
|
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
3426
|
13 ## General Public License for more details. |
|
14 ## |
3191
|
15 ## You should have received a copy of the GNU General Public License |
3922
|
16 ## along with Octave; see the file COPYING. If not, write to the Free |
5307
|
17 ## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
|
18 ## 02110-1301, USA. |
3191
|
19 |
3449
|
20 ## -*- texinfo -*- |
|
21 ## @deftypefn {Function File} {} spencer (@var{x}) |
|
22 ## Return Spencer's 15 point moving average of every single column of |
|
23 ## @var{x}. |
|
24 ## @end deftypefn |
3426
|
25 |
3457
|
26 ## Author: FL <Friedrich.Leisch@ci.tuwien.ac.at> |
|
27 ## Description: Apply Spencer's 15-point MA filter |
3191
|
28 |
|
29 function retval = spencer (X) |
3426
|
30 |
3191
|
31 if (nargin != 1) |
6046
|
32 print_usage (); |
3191
|
33 endif |
|
34 |
3238
|
35 [xr, xc] = size(X); |
3426
|
36 |
3191
|
37 n = xr; |
|
38 c = xc; |
3426
|
39 |
4030
|
40 if (isvector(X)) |
3191
|
41 n = length(X); |
|
42 c = 1; |
|
43 X = reshape(X, n, 1); |
|
44 endif |
3426
|
45 |
3238
|
46 W = [-3, -6, -5, 3, 21, 46, 67, 74, 67, 46, 21, 3, -5, -6, -3] / 320; |
3191
|
47 |
|
48 retval = fftfilt (W, X); |
|
49 retval = [zeros(7,c); retval(15:n,:); zeros(7,c);]; |
3426
|
50 |
3191
|
51 retval = reshape(retval, xr, xc); |
3426
|
52 |
3191
|
53 endfunction |
|
54 |
|
55 |
|
56 |
|
57 |
|
58 |
|
59 |
|
60 |
|
61 |
|
62 |
|
63 |
|
64 |