mtfftc

PURPOSE ^

Multi-taper fourier transform - continuous data

SYNOPSIS ^

function J=mtfftc(data,tapers,nfft)

DESCRIPTION ^

 Multi-taper fourier transform - continuous data

 Usage:
 J=mtfftc(data,tapers,nfft) - all arguments required
 Input: 
       data (in form samples x channels/trials) 
       tapers (precalculated tapers from dpss) 
       nfft (length of padded data)
                                   
 Output:
       J (fft in form frequency index x taper index x channels/trials)

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function J=mtfftc(data,tapers,nfft)
0002 % Multi-taper fourier transform - continuous data
0003 %
0004 % Usage:
0005 % J=mtfftc(data,tapers,nfft) - all arguments required
0006 % Input:
0007 %       data (in form samples x channels/trials)
0008 %       tapers (precalculated tapers from dpss)
0009 %       nfft (length of padded data)
0010 %
0011 % Output:
0012 %       J (fft in form frequency index x taper index x channels/trials)
0013 if nargin < 3; error('Need all arguments'); end;
0014 [NC,C]=size(data); % size of data
0015 [NK K]=size(tapers); % size of tapers
0016 if NK~=NC; error('length of tapers is incompatible with length of data'); end;
0017 tapers=tapers(:,:,ones(1,C)); % add channel indices to tapers
0018 data=data(:,:,ones(1,K)); % add taper indices to data
0019 data=permute(data,[1 3 2]); % reshape data to get dimensions to match those of tapers
0020 data_proj=data.*tapers; % product of data with tapers
0021 J=fft(data_proj,nfft);   % fft of projected data

Generated on Tue 24-Aug-2004 15:55:33 by m2html © 2003