


Multi-taper spectrum - point process times
Usage:
[S,f,R,Serr]=mtspectrumpt(data,tapers,pad,Fs,fpass,err,trialave,fscorr,t)
Input:
data (structure array of spike times with dimension channels/trials; 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 for fft grid used to calculate fft of prolates. 1/Fs is the time between consecutive
points on the grid used for evaluation of the prolates) - 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:
S (spectrum in form frequency x channels/trials)
f (frequencies)
R (rate)
Serr (error bars)

0001 function [S,f,R,Serr]=mtspectrumpt(data,tapers,pad,Fs,fpass,err,trialave,fscorr,t) 0002 % Multi-taper spectrum - point process times 0003 % 0004 % Usage: 0005 % 0006 % [S,f,R,Serr]=mtspectrumpt(data,tapers,pad,Fs,fpass,err,trialave,fscorr,t) 0007 % Input: 0008 % data (structure array of spike times with dimension channels/trials; 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 for fft grid used to calculate fft of prolates. 1/Fs is the time between consecutive 0016 % points on the grid used for evaluation of the prolates) - optional. Default 1. 0017 % fpass (frequency band to be used in the calculation in the form 0018 % [fmin fmax])- optional. 0019 % Default all frequencies between 0 and Fs/2 0020 % err (error calculation [1 p] - Theoretical error bars; [2 p] Jackknife error bars 0021 % [0 p] or 0 - no error bars) - optional. Default 0. 0022 % trialave (average over trials when 1, don't average when 0) - optional. Default 0 0023 % fscorr (finite size corrections, 0 (don't use finite size corrections) or 1 (use finite size corrections) - optional 0024 % (available only for spikes). Defaults 0. 0025 % t (time grid over which the tapers are to be calculated: 0026 % this argument is useful when calling the spectrum 0027 % calculation routine from a moving window spectrogram 0028 % calculation routine). If left empty, the spike times 0029 % are used to define the grid. 0030 % Output: 0031 % S (spectrum in form frequency x channels/trials) 0032 % f (frequencies) 0033 % R (rate) 0034 % Serr (error bars) 0035 if nargin < 1; error('Need data'); end; 0036 if nargin < 2; tapers=[3 5];end; 0037 if nargin < 3; pad=0;end; 0038 if nargin < 4; Fs=1; end; 0039 if nargin < 5; fpass=[0 Fs/2]; end; 0040 if nargin < 6; err=0; end; 0041 if nargin < 7; trialave=0; end; 0042 if nargin < 8; fscorr=0;end; 0043 if nargin < 9; 0044 [mintime,maxtime]=minmaxsptimes(data); 0045 dt=1/Fs; % sampling time 0046 t=mintime-dt:dt:maxtime+dt; % time grid for prolates 0047 end; 0048 N=length(t); % number of points in grid for dpss 0049 if isempty(tapers); tapers=[3 5]; end; 0050 if isempty(pad);pad=0;end; 0051 if isempty(Fs); Fs=1; end; 0052 if isempty(fpass); fpass=[0 Fs/2]; end; 0053 if isempty(err); err=0; end; 0054 if isempty(trialave); trialave=0;end; 0055 if isempty(fscorr);fscorr=0;end 0056 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 S=squeeze(mean(conj(J).*J,2)); 0062 if trialave; S=squeeze(mean(S,2));Msp=mean(Msp);end; 0063 R=Msp*Fs; 0064 if nargout==4; 0065 if fscorr==1; 0066 Serr=specerr(S,J,err,trialave,Nsp); 0067 else; 0068 Serr=specerr(S,J,err,trialave); 0069 end; 0070 end;