Mercurial > octave-nkf
view scripts/signal/fftconv.m @ 11085:2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
author | Rik <octave@nomad.inbox5.com> |
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date | Thu, 07 Oct 2010 11:27:03 -0700 |
parents | a1dbe9d80eee |
children | e79f59d31a74 |
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## Copyright (C) 1994, 1995, 1996, 1997, 1999, 2000, 2002, 2005, 2006, ## 2007 John W. Eaton ## ## This file is part of Octave. ## ## Octave 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 3 of the License, or (at ## your option) any later version. ## ## Octave 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 Octave; see the file COPYING. If not, see ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} fftconv (@var{a}, @var{b}) ## @deftypefnx {Function File} {} fftconv (@var{a}, @var{b}, @var{n}) ## Convolve two vectors using the FFT for computation. ## ## @code{c = fftconv (@var{a}, @var{b})} returns a vector of length equal to ## @code{length (@var{a}) + length (@var{b}) - 1}. ## If @var{a} and @var{b} are the coefficient vectors of two polynomials, the ## returned value is the coefficient vector of the product polynomial. ## ## The computation uses the FFT by calling the function @code{fftfilt}. If ## the optional argument @var{n} is specified, an N-point FFT is used. ## @seealso{deconv, conv, conv2} ## @end deftypefn ## Author: KH <Kurt.Hornik@wu-wien.ac.at> ## Created: 3 September 1994 ## Adapted-By: jwe function c = fftconv (a, b, N) if (nargin < 2 || nargin > 3) print_usage (); endif if (! (isvector (a) && isvector (b))) error ("fftconv: both A and B must be vectors"); endif la = length (a); lb = length (b); if ((la == 1) || (lb == 1)) c = a * b; else lc = la + lb - 1; a(lc) = 0; b(lc) = 0; if (nargin == 2) c = fftfilt (a, b); else if (! (isscalar (N))) error ("fftconv: N must be a scalar"); endif c = fftfilt (a, b, N); endif endif endfunction %% FIXME: Borrow tests from conv.m. May need a tolerance on the assert comparison