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- function [C,phi,S12,S1,S2,t,f,confC,phistd,Cerr]=cohgramc(data1,data2,movingwin,params)
- % Multi-taper time-frequency coherence,cross-spectrum and individual spectra - continuous processes
- %
- % Usage:
- %
- % [C,phi,S12,S1,S2,t,f,confC,phistd,Cerr]=cohgramc(data1,data2,movingwin,params)
- % Input:
- % Note units have to be consistent. Thus, if movingwin is in seconds, Fs
- % has to be in Hz. see chronux.m for more information.
- %
- % data1 (in form samples x trials) -- required
- % data2 (in form samples x trials) -- required
- % movingwin (in the form [window winstep] -- required
- % params: structure with fields tapers, pad, Fs, fpass, err, trialave
- % - optional
- % tapers : precalculated tapers from dpss or in the one of the following
- % forms:
- % (1) A numeric vector [TW K] where TW is the
- % time-bandwidth product and K is the number of
- % tapers to be used (less than or equal to
- % 2TW-1).
- % (2) A numeric vector [W T p] where W is the
- % bandwidth, T is the duration of the data and p
- % is an integer such that 2TW-p tapers are used. In
- % this form there is no default i.e. to specify
- % the bandwidth, you have to specify T and p as
- % well. Note that the units of W and T have to be
- % consistent: if W is in Hz, T must be in seconds
- % and vice versa. Note that these units must also
- % be consistent with the units of params.Fs: W can
- % be in Hz if and only if params.Fs is in Hz.
- % The default is to use form 1 with TW=3 and K=5
- % Note that T has to be equal to movingwin(1).
- %
- % pad (padding factor for the FFT) - optional (can take values -1,0,1,2...).
- % -1 corresponds to no padding, 0 corresponds to padding
- % to the next highest power of 2 etc.
- % e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
- % to 512 points, if pad=1, we pad to 1024 points etc.
- % Defaults to 0.
- % 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
- % err (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars
- % [0 p] or 0 - no error bars) - optional. Default 0.
- % trialave (average over trials when 1, don't average when 0) - optional. Default 0
- % Output:
- % C (magnitude of coherency time x frequencies x trials for trialave=0;
- % time x frequency for trialave=1)
- % phi (phase of coherency time x frequencies x trials for no trial averaging;
- % time x frequency for trialave=1)
- % S12 (cross spectrum - time x frequencies x trials for no trial averaging;
- % time x frequency for trialave=1)
- % S1 (spectrum 1 - time x frequencies x trials for no trial averaging;
- % time x frequency for trialave=1)
- % S2 (spectrum 2 - time x frequencies x trials for no trial averaging;
- % time x frequency for trialave=1)
- % t (time)
- % f (frequencies)
- % confC (confidence level for C at 1-p %) - only for err(1)>=1
- % phistd - theoretical/jackknife (depending on err(1)=1/err(1)=2) standard deviation for phi
- % Note that phi + 2 phistd and phi - 2 phistd will give 95% confidence
- % bands for phi - only for err(1)>=1
- % Cerr (Jackknife error bars for C - use only for Jackknife - err(1)=2)
- if nargin < 3; error('Need data1 and data2 and window parameters'); end;
- if nargin < 4; params=[];end;
- if ~isempty(params) && length(params.tapers)==3 && movingwin(1)~=params.tapers(2);
- error('Duration of data in params.tapers is inconsistent with movingwin(1), modify params.tapers(2) to proceed')
- end
- [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params);
- if nargout > 9 && err(1)~=2;
- error('Cerr computed only for Jackknife. Correct inputs and run again');
- end;
- if nargout > 7 && err(1)==0;
- % Errors computed only if err(1) is nonzero. Need to change params and run again.
- error('When errors are desired, err(1) has to be non-zero.');
- end;
- [N,Ch]=check_consistency(data1,data2);
- Nwin=round(Fs*movingwin(1)); % number of samples in window
- Nstep=round(movingwin(2)*Fs); % number of samples to step through
- nfft=max(2^(nextpow2(Nwin)+pad),Nwin);
- f=getfgrid(Fs,nfft,fpass);
- Nf=length(f);
- params.tapers=dpsschk(tapers,Nwin,Fs); % check tapers
- winstart=1:Nstep:N-Nwin+1;
- nw=length(winstart);
- if trialave;
- C=zeros(nw,Nf);
- S12=zeros(nw,Nf);
- S1=zeros(nw,Nf);
- S2=zeros(nw,Nf);
- phi=zeros(nw,Nf);
- Cerr=zeros(2,nw,Nf);
- % phierr=zeros(2,nw,Nf);
- phistd=zeros(nw,Nf);
- else
- C=zeros(nw,Nf,Ch);
- S12=zeros(nw,Nf,Ch);
- S1=zeros(nw,Nf,Ch);
- S2=zeros(nw,Nf,Ch);
- phi=zeros(nw,Nf,Ch);
- Cerr=zeros(2,nw,Nf,Ch);
- % phierr=zeros(2,nw,Nf,Ch);
- phistd=zeros(nw,Nf,Ch);
- end;
- for n=1:nw;
- indx=winstart(n):winstart(n)+Nwin-1;
- datawin1=data1(indx,:);datawin2=data2(indx,:);
- if nargout==10;
- [c,ph,s12,s1,s2,f,confc,phie,cerr]=coherencyc(datawin1,datawin2,params);
- % phierr(1,n,:,:)=squeeze(phie(1,:,:));
- % phierr(2,n,:,:)=squeeze(phie(2,:,:));
- phistd(n,:,:)=phie;
- Cerr(1,n,:,:)=squeeze(cerr(1,:,:));
- Cerr(2,n,:,:)=squeeze(cerr(2,:,:));
- elseif nargout==9;
- [c,ph,s12,s1,s2,f,confc,phie]=coherencyc(datawin1,datawin2,params);
- % phierr(1,n,:,:)=squeeze(phie(1,:,:));
- % phierr(2,n,:,:)=squeeze(phie(2,:,:));
- phistd(n,:,:)=phie;
- else
- [c,ph,s12,s1,s2,f]=coherencyc(datawin1,datawin2,params);
- end;
- C(n,:,:)=c;
- S12(n,:,:)=s12;
- S1(n,:,:)=s1;
- S2(n,:,:)=s2;
- phi(n,:,:)=ph;
- end;
- C=squeeze(C); phi=squeeze(phi);S12=squeeze(S12); S1=squeeze(S1); S2=squeeze(S2);
- if nargout > 8; confC=confc; end;
- if nargout==10;Cerr=squeeze(Cerr);end;
- % if nargout>=9; phierr=squeeze(phierr);end
- if nargout>=9; phistd=squeeze(phistd);end
- winmid=winstart+round(Nwin/2);
- t=winmid/Fs;
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