


Multi-taper spectrum - continuous process
Usage:
[S12,f]=crossspecc(data1,data2,tapers,pad,Fs,fpass)
Input:
Note units have to be consistent. See chronux.m for more information.
data1 (in form samples x channels/trials) -- required
data2 (in form samples x channels/trials) -- required
tapers (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not
specified, use [NW K]=[3 5]
pad (padding factor for the FFT) - optional. Defaults to 0.
e.g. For N = 500, if PAD = 0, we pad the FFT
to 512 points; if PAD = 2, we pad the FFT
to 2048 points, etc.
Fs (sampling frequency) - optional. Default 1.
fpass (frequency band to be used in the calculation in the form
[fmin fmax])- optional.
Default all frequencies between 0 and Fs/2
Output:
S12 (cross spectrum frequency x channels/trials)
f (frequencies)

0001 function [S12,f]=crossspecc(data1,data2,tapers,pad,Fs,fpass) 0002 % 0003 % 0004 % Multi-taper spectrum - continuous process 0005 % 0006 % Usage: 0007 % 0008 % [S12,f]=crossspecc(data1,data2,tapers,pad,Fs,fpass) 0009 % Input: 0010 % Note units have to be consistent. See chronux.m for more information. 0011 % data1 (in form samples x channels/trials) -- required 0012 % data2 (in form samples x channels/trials) -- required 0013 % tapers (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not 0014 % specified, use [NW K]=[3 5] 0015 % pad (padding factor for the FFT) - optional. Defaults to 0. 0016 % e.g. For N = 500, if PAD = 0, we pad the FFT 0017 % to 512 points; if PAD = 2, we pad the FFT 0018 % to 2048 points, etc. 0019 % Fs (sampling frequency) - optional. Default 1. 0020 % fpass (frequency band to be used in the calculation in the form 0021 % [fmin fmax])- optional. 0022 % Default all frequencies between 0 and Fs/2 0023 % Output: 0024 % S12 (cross spectrum frequency x channels/trials) 0025 % f (frequencies) 0026 if nargin < 2; error('Need data1 and data2'); end; 0027 [N,C]=size(data1); 0028 if nargin < 3; tapers=[3 5]; end; 0029 if nargin < 4;pad=0;end; 0030 if nargin < 5; Fs=1; end; 0031 if nargin < 6; fpass=[0 Fs/2]; end; 0032 if isempty(tapers); tapers=[3 5]; end; 0033 if isempty(pad);pad=0;end; 0034 if isempty(Fs); Fs=1; end; 0035 if isempty(fpass); fpass=[0 Fs/2]; end; 0036 0037 nfft=2^(nextpow2(N)+pad); 0038 [f,findx]=getfgrid(Fs,nfft,fpass); 0039 tapers=dpsschk(tapers,N); % check tapers 0040 J1=mtfftc(data1,tapers,nfft); 0041 J2=mtfftc(data2,tapers,nfft); 0042 J1=J1(findx,:,:); J2=J2(findx,:,:); 0043 S12=squeeze(mean(conj(J1).*J2,2)); 0044 if trialave; S12=squeeze(mean(S12,2));end;