Mercurial > octave-dspies
view scripts/signal/fftconv.m @ 18995:8ac4ab4ae5f4
periodogram.m: Overhaul function (bug #39279, bug #42859).
* contributors.in: Add Drew Abbot to list of contributors.
* periodogram.m: Rewrite documentation. Simplify input parsing of arguments.
Accept both row and column inputs for X. Correct onesided computation
when NFFT is odd. Add an error message about unrecognized range specification
"centered". Add input validation tests.
author | Drew Abbot <drewabbot@gmail.com> and Rik <rik@octave.org> |
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date | Thu, 07 Aug 2014 10:13:30 -0700 |
parents | d63878346099 |
children |
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## Copyright (C) 1994-2013 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{x}, @var{y}) ## @deftypefnx {Function File} {} fftconv (@var{x}, @var{y}, @var{n}) ## Convolve two vectors using the FFT for computation. ## ## @code{c = fftconv (@var{x}, @var{y})} returns a vector of length equal to ## @code{length (@var{x}) + length (@var{y}) - 1}. ## If @var{x} and @var{y} 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 (x, y, n) if (nargin < 2 || nargin > 3) print_usage (); endif if (! (isvector (x) && isvector (y))) error ("fftconv: both A and B must be vectors"); endif la = length (x); lb = length (y); if ((la == 1) || (lb == 1)) c = x * y; else lc = la + lb - 1; x(lc) = 0; y(lc) = 0; if (nargin == 2) c = fftfilt (x, y); else if (! isscalar (n)) error ("fftconv: N must be a scalar"); endif c = fftfilt (x, y, n); endif endif endfunction %% FIXME: Borrow tests from conv.m. May need a tolerance on the assert comparison %!test %! x = ones (3,1); %! y = ones (1,3); %! b = 2; %! c = 3; %! assert (fftconv (x, x), [1; 2; 3; 2; 1], 5*eps); %! assert (fftconv (y, y), [1, 2, 3, 2, 1], 5*eps); %! assert (fftconv (x, y), [1, 2, 3, 2, 1], 5*eps); %! assert (fftconv (y, x), [1; 2; 3; 2; 1], 5*eps); %! assert (fftconv (c, x), [3; 3; 3], 5*eps); %! assert (fftconv (c, y), [3, 3, 3], 5*eps); %! assert (fftconv (x, c), [3; 3; 3], 5*eps); %! assert (fftconv (y, c), [3, 3, 3], 5*eps); %! assert (fftconv (b, c), 6, 5*eps); %!test %! a = 1:10; %! b = 1:3; %! assert (size (conv (a,b)), [1, numel(a)+numel(b)-1]); %! assert (size (conv (b,a)), [1, numel(a)+numel(b)-1]); %! a = (1:10).'; %! b = 1:3; %! assert (size (conv (a,b)), [numel(a)+numel(b)-1, 1]); %! assert (size (conv (b,a)), [numel(a)+numel(b)-1, 1]); %!test %! a = 1:10; %! b = (1:3).'; %! assert (size (conv (a,b)), [1, numel(a)+numel(b)-1]); %! assert (size (conv (b,a)), [1, numel(a)+numel(b)-1]); %% Test input validation %!error fftconv (1) %!error fftconv (1,2,3,4) %!error fftconv ([1, 2; 3, 4], 3) %!error fftconv (2, []) %!error fftconv ([1,1], [2,2] , [3, 4])