www.gusucode.com > 线性时频分析工具箱 - ltfat-1.0.1源码程序 > 线性时频分析工具箱 - LTFAT\fourier\dft.m
function f=dft(f,N,dim); %DFT Normalized Discrete Fourier Transform % Usage: f=dft(f); % f=dft(f,N,dim); % % DFT computes a normalized discrete Fourier transform. This is nothing % but a scaled version of the output from FFT. The function takes exactly % the same arguments as FFT. See the help on FFT for a thorough % description. % % See also: idft % Copyright (C) 2005-2011 Peter L. Soendergaard. % This file is part of LTFAT version 1.0.1 % 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 3 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 should have received a copy of the GNU General Public License % along with this program. If not, see <http://www.gnu.org/licenses/>. % AUTHOR: Peter Soendergaard % TESTING: OK % REFERENCE: OK error(nargchk(1,3,nargin)); if nargin<3 dim=[]; end; if nargin<2 N=[]; end; [f,N,Ls,W,dim,permutedsize,order]=assert_sigreshape_pre(f,N,dim,'DFT'); % Force FFT along dimension 1, since we have permuted the dimensions % manually f=fft(f,N,1)/sqrt(N); f=assert_sigreshape_post(f,dim,permutedsize,order);