function [C,phi,S12,S1,S2,f,zerosp,confC,phistd,Cerr]=coherencycpt(data1,data2,params,fscorr,t) % Multi-taper coherency,cross-spectrum and individual spectra -continuous data and point process as times % % Usage: % % [C,phi,S12,S1,S2,f,zerosp,confC,phistd,Cerr]=coherencycpt(data1,data2,params,fscorr,t) % Input: % data1 (continuous data in time x trials form) -- required % data2 (structure array of spike times with dimension trials; % also accepts 1d array of spike times) -- 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 % % 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 % fscorr (finite size corrections, 0 (don't use finite size corrections) or % 1 (use finite size corrections) - optional % (available only for spikes). Defaults 0. % t (time grid over which the tapers are to be calculated: % this argument is useful when calling the spectrum % calculation routine from a moving window spectrogram % calculation routine). If left empty, the spike times % are used to define the grid. % Output: % C (magnitude of coherency - frequencies x trials if trialave=0; dimension frequencies if trialave=1) % phi (phase of coherency - frequencies x trials if trialave=0; dimension frequencies if trialave=1) % S12 (cross spectrum - frequencies x trials if trialave=0; dimension frequencies if trialave=1) % S1 (spectrum 1 - frequencies x trials if trialave=0; dimension frequencies if trialave=1) % S2 (spectrum 2 - frequencies x trials if trialave=0; dimension frequencies if trialave=1) % f (frequencies) % zerosp (1 for trials where no spikes were found, 0 otherwise) % 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 < 2; error('Need data1 and data2'); end; if nargin < 3; params=[]; end; [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params); clear params if nargin < 4 || isempty(fscorr); fscorr=0; end; if nargin < 5 || isempty(t); [N,C]=size(data1); dt=1/Fs; t=0:dt:(N-1)*dt; % time grid for prolates end; if nargout > 7 && err(1)==0; % Errors computed only if err(1) is non-zero. Need to change params and run again. error('When errors are desired, err(1) has to be non-zero.'); end; if nargout > 9 && err(1)~=2; error('Cerr computed only for Jackknife. Correct inputs and run again'); end; [N,Ch]=check_consistency(data1,data2,1); zerosp=zeros(1,Ch); % intialize the zerosp variable N=length(t); % number of points in grid for dpss nfft=max(2^(nextpow2(N)+pad),N); % number of points in fft of prolates [f,findx]=getfgrid(Fs,nfft,fpass); tapers=dpsschk(tapers,N,Fs); % check tapers J1=mtfftc(data1,tapers,nfft,Fs); % fourier transform of continuous data J1=J1(findx,:,:); % restrict to required frequencies [J2,Msp2,Nsp2]=mtfftpt(data2,tapers,nfft,t,f,findx); % fourier transform of discrete data zerosp(Nsp2==0)=1; % set zerosp to 1 for trials where no spikes were found S12=squeeze(mean(conj(J1).*J2,2)); % cross spectrum S1=squeeze(mean(conj(J1).*J1,2)); % spectrum data 1 S2=squeeze(mean(conj(J2).*J2,2)); % spectrum data 2 if trialave; S12=squeeze(mean(S12,2)); S1=squeeze(mean(S1,2)); S2=squeeze(mean(S2,2)); end; C12=S12./sqrt(S1.*S2); C=abs(C12); phi=angle(C12); if nargout==10; if fscorr==1; [confC,phistd,Cerr]=coherr(C,J1,J2,err,trialave,[],Nsp2); else [confC,phistd,Cerr]=coherr(C,J1,J2,err,trialave); end; elseif nargout==9; if fscorr==1; [confC,phistd]=coherr(C,J1,J2,err,trialave,[],Nsp2); else [confC,phistd]=coherr(C,J1,J2,err,trialave); end; end; clear Msp2