Home > chronux_1_1 > hybrid > coherencysegcpt.m

coherencysegcpt

PURPOSE ^

Multi-taper coherency,cross-spectrum and individual spectra computed by segmenting two univariate time series into chunks - continuous and point process stored as times

SYNOPSIS ^

function [C,phi,S12,S1,S2,f,zerosp,confC,phierr,Cerr]=coherencysegcpt(data1,data2,win,params,segave,fscorr)

DESCRIPTION ^

 Multi-taper coherency,cross-spectrum and individual spectra computed by segmenting two univariate time series into chunks - continuous and point process stored as times

 Usage:
 [C,phi,S12,S1,S2,f,zerosp,confC,phierr,Cerr]=coherencysegcpt(data1,data2,win,params,segave,fscorr)
 Input: 
 Note units have to be consistent. See chronux.m for more information.
       data1 (column vector, continuous data) -- required
       data2 (1d structure array of spike times; also accepts 1d array of spike times) -- required
       params: structure with fields tapers, pad, Fs, fpass, err
       - optional
           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
           err  (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars
                                   [0 p] or 0 - no error bars) - optional. Default 0.
       segave (average over segments for 1, don't average for 0)- optional. Default 1
       fscorr   (finite size corrections, 0 (don't use finite size corrections) or 1 (use finite size corrections) - optional
                (available only for spikes). Defaults 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)
       zerosp (1 for trials where no spikes were found, 0 otherwise)
       confC (confidence level for C at 1-p %) - only for err(1)>=1
       phierr - standard deviation for phi (note that the routine gives phierr as phierr(1,...) and phierr(2,...) 
                in order to incorporate Jackknife (eventually). Currently phierr(1,...)=phierr(2,...). Note that 
                phi + 2 phierr(1,...) and phi -2 phierr(2,...) 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)

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [C,phi,S12,S1,S2,f,zerosp,confC,phierr,Cerr]=coherencysegcpt(data1,data2,win,params,segave,fscorr)
0002 % Multi-taper coherency,cross-spectrum and individual spectra computed by segmenting two univariate time series into chunks - continuous and point process stored as times
0003 %
0004 % Usage:
0005 % [C,phi,S12,S1,S2,f,zerosp,confC,phierr,Cerr]=coherencysegcpt(data1,data2,win,params,segave,fscorr)
0006 % Input:
0007 % Note units have to be consistent. See chronux.m for more information.
0008 %       data1 (column vector, continuous data) -- required
0009 %       data2 (1d structure array of spike times; also accepts 1d array of spike times) -- required
0010 %       params: structure with fields tapers, pad, Fs, fpass, err
0011 %       - optional
0012 %           tapers (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not
0013 %                                                 specified, use [NW K]=[3 5]
0014 %            pad            (padding factor for the FFT) - optional. Defaults to 0.
0015 %                       e.g. For N = 500, if PAD = 0, we pad the FFT
0016 %                       to 512 points; if PAD = 2, we pad the FFT
0017 %                       to 2048 points, etc.
0018 %           Fs   (sampling frequency) - optional. Default 1.
0019 %           fpass    (frequency band to be used in the calculation in the form
0020 %                                   [fmin fmax])- optional.
0021 %                                   Default all frequencies between 0 and Fs/2
0022 %           err  (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars
0023 %                                   [0 p] or 0 - no error bars) - optional. Default 0.
0024 %       segave (average over segments for 1, don't average for 0)- optional. Default 1
0025 %       fscorr   (finite size corrections, 0 (don't use finite size corrections) or 1 (use finite size corrections) - optional
0026 %                (available only for spikes). Defaults 0.
0027 % Output:
0028 %       C (magnitude of coherency - frequencies x segments if segave=0; dimension frequencies if segave=1)
0029 %       phi (phase of coherency - frequencies x segments if segave=0; dimension frequencies if segave=1)
0030 %       S12 (cross spectrum -  frequencies x segments if segave=0; dimension frequencies if segave=1)
0031 %       S1 (spectrum 1 - frequencies x segments if segave=0; dimension frequencies if segave=1)
0032 %       S2 (spectrum 2 - frequencies x segments if segave=0; dimension frequencies if segave=1)
0033 %       f (frequencies)
0034 %       zerosp (1 for trials where no spikes were found, 0 otherwise)
0035 %       confC (confidence level for C at 1-p %) - only for err(1)>=1
0036 %       phierr - standard deviation for phi (note that the routine gives phierr as phierr(1,...) and phierr(2,...)
0037 %                in order to incorporate Jackknife (eventually). Currently phierr(1,...)=phierr(2,...). Note that
0038 %                phi + 2 phierr(1,...) and phi -2 phierr(2,...) will give 95% confidence bands for phi - only for err(1)>=1
0039 %       Cerr  (Jackknife error bars for C - use only for Jackknife - err(1)=2)
0040 
0041 if nargin < 3; error('Need data1 and data2 and size of segment'); end;
0042 if nargin < 4; params=[]; end;
0043 [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params);
0044 if nargin < 5 || isempty(segave); segave=1;end;
0045 if nargin < 6 || isempty(fscorr); fscorr=0; end;
0046 if nargout > 7 && err(1)==0;
0047 %   Errors computed only if err(1) is non-zero. Need to change params and run again.
0048     error('When errors are desired, err(1) has to be non-zero.');
0049 end;
0050 if nargout > 9 && err(1)~=2; 
0051     error('Cerr computed only for Jackknife. Correct inputs and run again');
0052 end;
0053 
0054 
0055 N=check_consistency(data1,data2,1);
0056 dt=1/Fs; % sampling interval
0057 T=N*dt; % length of data in seconds
0058 E=0:win:T-win; % fictitious event triggers
0059 win=[0 win]; % use window length to define left and right limits of windows around triggers
0060 data1=createdatamatc(data1,E,Fs,win); % segmented data 1
0061 data2=createdatamatpt(data2,E,win); % segmented data 2
0062 params.trialave=segave;
0063 if nargout==7;
0064   [C,phi,S12,S1,S2,f,zerosp]=coherencycpt(data1,data2,params,fscorr); % compute coherency for segmented data
0065 elseif nargout==9; 
0066   [C,phi,S12,S1,S2,f,zerosp,confC,phierr]=coherencycpt(data1,data2,params,fscorr); % compute coherency for segmented data
0067 elseif nargout==10;
0068   [C,phi,S12,S1,S2,f,zerosp,confC,phierr,Cerr]=coherencycpt(data1,data2,params,fscorr); % compute coherency for segmented data
0069 end;

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