


Multi-taper coherency matrix - point process times
Usage:
[C,phi,S12,f,zerosp,confC,phierr,Cerr]=cohmatrixpt(data,tapers,pad,Fs,fpass,err,fscorr)
Input:
data (structure array of spike times with dimension channels; also accepts 1d array of spike times) - 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 (binning 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.
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 (abs of coherency frequency index x channels x channels)
phi (phase of coherency frequency x channels x channels)
S12 (cross-spectral matrix frequency x channnels x channels)
f (frequencies)
zerosp (1 for channels where no spikes were found, zero otherwise)
confC (confidence level for c at 1-p %)
phierr (error bars for phi)
Cerr (error bars for C)

0001 function [C,phi,S12,f,zerosp,confC,phierr,Cerr]=cohmatrixpt(data,tapers,pad,Fs,fpass,err,fscorr) 0002 % Multi-taper coherency matrix - point process times 0003 % 0004 % Usage: 0005 % 0006 % [C,phi,S12,f,zerosp,confC,phierr,Cerr]=cohmatrixpt(data,tapers,pad,Fs,fpass,err,fscorr) 0007 % Input: 0008 % data (structure array of spike times with dimension channels; also accepts 1d array of spike times) - required 0009 % tapers (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not 0010 % specified, use [NW K]=[3 5] 0011 % pad (padding factor for the FFT) - optional. Defaults to 0. 0012 % e.g. For N = 500, if PAD = 0, we pad the FFT 0013 % to 512 points; if PAD = 2, we pad the FFT 0014 % to 2048 points, etc. 0015 % Fs (binning frequency) - optional. Default 1. 0016 % fpass (frequency band to be used in the calculation in the form 0017 % [fmin fmax])- optional. 0018 % Default all frequencies between 0 and Fs/2 0019 % err (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars 0020 % [0 p] or 0 - no error bars) - optional. Default 0. 0021 % fscorr (finite size corrections, 0 (don't use finite size corrections) or 1 (use finite size corrections) - optional 0022 % (available only for spikes). Defaults 0. 0023 % Output: 0024 % C (abs of coherency frequency index x channels x channels) 0025 % phi (phase of coherency frequency x channels x channels) 0026 % S12 (cross-spectral matrix frequency x channnels x channels) 0027 % f (frequencies) 0028 % zerosp (1 for channels where no spikes were found, zero otherwise) 0029 % confC (confidence level for c at 1-p %) 0030 % phierr (error bars for phi) 0031 % Cerr (error bars for C) 0032 0033 if isstruct(data) 0034 Ch=length(data); 0035 if Ch==1; error('Need at least 2 channels'); end; 0036 else 0037 error('Need at least two channels of data in the a structural array'); 0038 end; 0039 if nargin < 2; tapers=[3 5]; end; 0040 if nargin < 3;pad=0;end; 0041 if nargin < 4; Fs=1; end; 0042 if nargin < 5; fpass=[0 Fs/2]; end; 0043 if nargin < 6; err=0; end; 0044 if nargin < 7; fscorr=0; end; 0045 0046 if isempty(tapers); tapers=[3 5]; end; 0047 if isempty(pad);pad=0;end; 0048 if isempty(Fs); Fs=1; end; 0049 if isempty(fpass); fpass=[0 Fs/2]; end; 0050 if isempty(err); err=0; end; 0051 if isempty(fscorr);fscorr=0;end 0052 0053 [mintime,maxtime]=minmaxsptimes(data); 0054 dt=1/Fs; % sampling time 0055 t=mintime:dt:maxtime+dt; % time grid for prolates 0056 N=length(t); % number of points in grid for dpss 0057 nfft=2^(nextpow2(N)+pad); % number of points in fft of prolates 0058 [f,findx]=getfgrid(Fs,nfft,fpass); % get frequency grid for evaluation 0059 tapers=dpsschk(tapers,N,Fs); % check tapers 0060 [J,Msp,Nsp]=mtfftpt(data,tapers,nfft,Fs,t,f,findx); % mt fft for point process times 0061 C1=size(J,3); 0062 zerosp=zeros(1,C1); % initialize the zerosp variable 0063 zerosp(Nsp==0)=0; % set the zerosp variable 0064 if err(1)==0; 0065 [C,phi,S12]=cohmathelper(J,err); 0066 elseif err(1)==1; 0067 if fscorr==0; 0068 [C,phi,S12,confC,phierr]=cohmathelper(J,err); 0069 else 0070 [C,phi,S12,confC,phierr]=cohmathelper(J,err,Nsp); 0071 end; 0072 elseif err(1)==2; 0073 if fscorr==0; 0074 [C,phi,S12,confC,phierr,Cerr]=cohmathelper(J,err); 0075 else 0076 [C,phi,S12,confC,phierr,Cerr]=cohmathelper(J,err,Nsp); 0077 end; 0078 end