Mercurial > hg > octave-lyh
annotate scripts/signal/fftconv.m @ 11188:4cb1522e4d0f
Use function handle as input to cellfun,
rather than quoted function name or anonymous function wrapper.
| author | Rik <octave@nomad.inbox5.com> |
|---|---|
| date | Wed, 03 Nov 2010 17:20:56 -0700 |
| parents | e79f59d31a74 |
| children | c776f063fefe |
| rev | line source |
|---|---|
| 7017 | 1 ## Copyright (C) 1994, 1995, 1996, 1997, 1999, 2000, 2002, 2005, 2006, |
| 2 ## 2007 John W. Eaton | |
| 2313 | 3 ## |
| 4 ## This file is part of Octave. | |
| 5 ## | |
| 6 ## Octave is free software; you can redistribute it and/or modify it | |
| 7 ## under the terms of the GNU General Public License as published by | |
| 7016 | 8 ## the Free Software Foundation; either version 3 of the License, or (at |
| 9 ## your option) any later version. | |
| 2313 | 10 ## |
| 11 ## Octave is distributed in the hope that it will be useful, but | |
| 12 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 ## General Public License for more details. | |
| 15 ## | |
| 16 ## You should have received a copy of the GNU General Public License | |
| 7016 | 17 ## along with Octave; see the file COPYING. If not, see |
| 18 ## <http://www.gnu.org/licenses/>. | |
| 1026 | 19 |
| 3367 | 20 ## -*- texinfo -*- |
|
11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
21 ## @deftypefn {Function File} {} fftconv (@var{a}, @var{b}) |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
22 ## @deftypefnx {Function File} {} fftconv (@var{a}, @var{b}, @var{n}) |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
23 ## Convolve two vectors using the FFT for computation. |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
24 ## |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
25 ## @code{c = fftconv (@var{a}, @var{b})} returns a vector of length equal to |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
26 ## @code{length (@var{a}) + length (@var{b}) - 1}. |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
27 ## If @var{a} and @var{b} are the coefficient vectors of two polynomials, the |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
28 ## returned value is the coefficient vector of the product polynomial. |
| 3426 | 29 ## |
| 3367 | 30 ## The computation uses the FFT by calling the function @code{fftfilt}. If |
| 31 ## the optional argument @var{n} is specified, an N-point FFT is used. | |
|
11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
32 ## @seealso{deconv, conv, conv2} |
| 3367 | 33 ## @end deftypefn |
| 787 | 34 |
| 5428 | 35 ## Author: KH <Kurt.Hornik@wu-wien.ac.at> |
| 2312 | 36 ## Created: 3 September 1994 |
| 37 ## Adapted-By: jwe | |
| 38 | |
| 2311 | 39 function c = fftconv (a, b, N) |
| 787 | 40 |
| 41 if (nargin < 2 || nargin > 3) | |
| 6046 | 42 print_usage (); |
| 787 | 43 endif |
| 2325 | 44 |
| 4030 | 45 if (! (isvector (a) && isvector (b))) |
|
11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
46 error ("fftconv: both A and B must be vectors"); |
| 787 | 47 endif |
| 48 la = length (a); | |
| 49 lb = length (b); | |
| 50 if ((la == 1) || (lb == 1)) | |
| 51 c = a * b; | |
| 52 else | |
| 53 lc = la + lb - 1; | |
| 54 a(lc) = 0; | |
| 55 b(lc) = 0; | |
| 56 if (nargin == 2) | |
| 57 c = fftfilt (a, b); | |
| 58 else | |
| 11124 | 59 if (! isscalar (N)) |
|
11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
60 error ("fftconv: N must be a scalar"); |
| 787 | 61 endif |
| 62 c = fftfilt (a, b, N); | |
| 63 endif | |
| 64 endif | |
| 65 | |
| 66 endfunction | |
|
11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
67 |
|
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
68 %% FIXME: Borrow tests from conv.m. May need a tolerance on the assert comparison |
| 11124 | 69 %!test |
| 70 %! x = ones(3,1); | |
| 71 %! y = ones(1,3); | |
| 72 %! b = 2; | |
| 73 %! c = 3; | |
| 74 %! assert (fftconv (x, x), [1; 2; 3; 2; 1], 5*eps); | |
| 75 %! assert (fftconv (y, y), [1, 2, 3, 2, 1], 5*eps); | |
| 76 %! assert (fftconv (x, y), [1, 2, 3, 2, 1], 5*eps); | |
| 77 %! assert (fftconv (y, x), [1; 2; 3; 2; 1], 5*eps); | |
| 78 %! assert (fftconv (c, x), [3; 3; 3], 5*eps); | |
| 79 %! assert (fftconv (c, y), [3, 3, 3], 5*eps); | |
| 80 %! assert (fftconv (x, c), [3; 3; 3], 5*eps); | |
| 81 %! assert (fftconv (y, c), [3, 3, 3], 5*eps); | |
| 82 %! assert (fftconv (b, c), 6, 5*eps); | |
| 83 | |
| 84 %!test | |
| 85 %! a = 1:10; | |
| 86 %! b = 1:3; | |
| 87 %! assert (size(conv(a,b)), [1, numel(a)+numel(b)-1]) | |
| 88 %! assert (size(conv(b,a)), [1, numel(a)+numel(b)-1]) | |
| 89 | |
| 90 %! a = (1:10).'; | |
| 91 %! b = 1:3; | |
| 92 %! assert (size(conv(a,b)), [numel(a)+numel(b)-1, 1]) | |
| 93 %! assert (size(conv(b,a)), [numel(a)+numel(b)-1, 1]) | |
| 94 | |
| 95 %!test | |
| 96 %! a = 1:10; | |
| 97 %! b = (1:3).'; | |
| 98 %! assert (size(conv(a,b)), [1, numel(a)+numel(b)-1]) | |
| 99 %! assert (size(conv(b,a)), [1, numel(a)+numel(b)-1]) | |
| 100 | |
| 101 %% Test input validation | |
| 102 %!error fftconv (1); | |
| 103 %!error fftconv (1,2,3,4); | |
| 104 %!error fftconv ([1, 2; 3, 4], 3); | |
| 105 %!error fftconv (2, []); | |
| 106 %!error fftconv ([1,1], [2,2] , [3, 4]); |