function [C,phi,S12,S1,S2,f,confC,phistd,Cerr]=coherencysegc(data1,data2,win,params) % Multi-taper coherency, cross-spectrum and individual spectra with segmenting - continuous process % computed by segmenting two univariate time series into chunks % % Usage: % [C,phi,S12,S1,S2,f,confC,phistd,Cerr]=coherencysegc(data1,data2,win,params) % Input: % Note units have to be consistent. See chronux.m for more information. % data1 (column vector) -- required % data2 (column vector) -- required % win (length of segments) - required % params: structure with fields tapers, pad, Fs, fpass, err % - 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. % Output: % C (magnitude of coherency - frequencies x segments if segave=0; dimension frequencies if segave=1) % phi (phase of coherency - frequencies x segments if segave=0; dimension frequencies if segave=1) % S12 (cross spectrum - frequencies x segments if segave=0; dimension frequencies if segave=1) % S1 (spectrum 1 - frequencies x segments if segave=0; dimension frequencies if segave=1) % S2 (spectrum 2 - frequencies x segments if segave=0; dimension frequencies if segave=1) % 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 size of segment'); end; if nargin < 4; params=[]; end; [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params); clear tapers pad fpass trialave if nargout > 8 && err(1)~=2; error('Cerr computed only for Jackknife. Correct inputs and run again'); end; if nargout > 6 && 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; if size(data1,2)~=1 || size(data2,2)~=1; error('works for only univariate time series'); end; N=check_consistency(data1,data2); dt=1/Fs; % sampling interval T=N*dt; % length of data in seconds E=0:win:T-win; % fictitious event triggers win=[0 win]; % use window length to define left and right limits of windows around triggers data1=createdatamatc(data1,E,Fs,win); % segmented data 1 data2=createdatamatc(data2,E,Fs,win); % segmented data 2 params.trialave=1; params.trialave=1; if err==0; [C,phi,S12,S1,S2,f]=coherencyc(data1,data2,params); % compute coherency for segmented data elseif err(1)==1; [C,phi,S12,S1,S2,f,confC,phistd]=coherencyc(data1,data2,params); % compute coherency for segmented data elseif err(1)==2; [C,phi,S12,S1,S2,f,confC,phistd,Cerr]=coherencyc(data1,data2,params); % compute coherency for segmented data end;