www.pudn.com > voicebox2.zip > IRFFT.M

function x=irfft(y,n) 
%IRFFT    Inverse fft of a conjugate symmetric spectrum X=(Y,N) 
% Y contains FIX(1+N/2) complex samples from the spectrum: if argument N 
% is specified then Y will be truncated or padded accordingly 
% IMPORTANT: If N is odd, it MUST be specified explicitly. 
% 
% See also RFFT 
 
 
 
%      Copyright (C) Mike Brookes 1998 
% 
%      Last modified Fri Apr  3 14:57:14 1998 
% 
%   VOICEBOX home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html 
% 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%   This program 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 2 of the License, or 
%   (at your option) any later version. 
% 
%   This program 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 can obtain a copy of the GNU General Public License from 
%   ftp://prep.ai.mit.edu/pub/gnu/COPYING-2.0 or by writing to 
%   Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
fl=size(y,1)==1; 
if fl y=y(:); end 
[m,k]=size(y); 
if nargin<2 n=2*m-2; 
else 
  mm=1+fix(n/2); 
  if mm>m y=[y; zeros(mm-m,k)]; 
  elseif mm