Home > chronux_1_0 > pointtimes > mtspecgrampt.m

mtspecgrampt

PURPOSE ^

Multi-taper time-frequency spectrum - point process times

SYNOPSIS ^

function [S,t,f,R,Serr]=mtspecgrampt(data,movingwin,params,fscorr)

DESCRIPTION ^

 Multi-taper time-frequency spectrum - point process times

 Usage:

 [S,t,f,R,Serr]=mtspecgrampt(data,movingwin,params,fscorr)
 Input: 
       data        (structure array of spike times with dimension channels/trials; also accepts 1d array of spike times) -- required
       movingwin         (in the form [window,winstep] i.e length of moving
                                                 window and step size.
                                                 
       params: structure with fields tapers, pad, Fs, fpass, err, trialave
       - 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.
           trialave (average over trials/channels 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.

 Output:
       S       (spectrogram with dimensions time x frequency x channels/trials if trialave=0; dimensions time x frequency if trialave=1)
       t       (times)
       f       (frequencies)

       Serr    (error bars) - only if err(1)>=1

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [S,t,f,R,Serr]=mtspecgrampt(data,movingwin,params,fscorr)
0002 % Multi-taper time-frequency spectrum - point process times
0003 %
0004 % Usage:
0005 %
0006 % [S,t,f,R,Serr]=mtspecgrampt(data,movingwin,params,fscorr)
0007 % Input:
0008 %       data        (structure array of spike times with dimension channels/trials; also accepts 1d array of spike times) -- required
0009 %       movingwin         (in the form [window,winstep] i.e length of moving
0010 %                                                 window and step size.
0011 %
0012 %       params: structure with fields tapers, pad, Fs, fpass, err, trialave
0013 %       - optional
0014 %           tapers (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not
0015 %                                                 specified, use [NW K]=[3 5]
0016 %            pad            (padding factor for the FFT) - optional. Defaults to 0.
0017 %                       e.g. For N = 500, if PAD = 0, we pad the FFT
0018 %                       to 512 points; if PAD = 2, we pad the FFT
0019 %                       to 2048 points, etc.
0020 %           Fs   (sampling frequency) - optional. Default 1.
0021 %           fpass    (frequency band to be used in the calculation in the form
0022 %                                   [fmin fmax])- optional.
0023 %                                   Default all frequencies between 0 and Fs/2
0024 %           err  (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars
0025 %                                   [0 p] or 0 - no error bars) - optional. Default 0.
0026 %           trialave (average over trials/channels when 1, don't average when 0) - optional. Default 0
0027 %       fscorr   (finite size corrections, 0 (don't use finite size corrections) or 1 (use finite size corrections) - optional
0028 %                (available only for spikes). Defaults 0.
0029 %
0030 % Output:
0031 %       S       (spectrogram with dimensions time x frequency x channels/trials if trialave=0; dimensions time x frequency if trialave=1)
0032 %       t       (times)
0033 %       f       (frequencies)
0034 %
0035 %       Serr    (error bars) - only if err(1)>=1
0036 
0037 if nargin < 2; error('Need data and window parameters'); end;
0038 if nargin < 3; params=[]; end;
0039 [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params);
0040 if isstruct(data); Ch=length(data); end;
0041 if nargin < 4 || isempty(fscorr); fscorr=0; end;
0042 if nargout > 4 && err(1)==0; error('Cannot compute errors with err(1)=0'); end;
0043 
0044 [mintime,maxtime]=minmaxsptimes(data);
0045 tn=(mintime+movingwin(1)/2:movingwin(2):maxtime-movingwin(1)/2);
0046 Nwin=round(Fs*movingwin(1)); % number of samples in window
0047 nfft=2^(nextpow2(Nwin)+pad);
0048 f=getfgrid(Fs,nfft,fpass); Nf=length(f);
0049 params.tapers=dpsschk(tapers,Nwin,Fs); % check tapers
0050 nw=length(tn);
0051 
0052 if trialave
0053     S = zeros(nw,Nf);
0054     R = zeros(nw,Nwin);
0055     if nargout==4; Serr=zeros(2,nw,Nf); end;
0056 else
0057     S = zeros(nw,Nf,Ch);
0058     R = zeros(nw,Nwin,Ch);
0059     if nargout==4; Serr=zeros(2,nw,Nf,Ch); end;
0060 end
0061 
0062 for n=1:nw;
0063    t=linspace(tn(n)-movingwin(1)/2,tn(n)+movingwin(1)/2,Nwin);
0064    datawin=extractdatapt(data,[t(1) t(end)]);
0065    if nargout==5;
0066      [s,f,r,serr]=mtspectrumpt(datawin,params,fscorr,t);
0067      Serr(1,n,:,:)=squeeze(serr(1,:,:));
0068      Serr(2,n,:,:)=squeeze(serr(2,:,:));
0069    else
0070      [s,f,r]=mtspectrumpt(datawin,params,fscorr,t);
0071    end;
0072    S(n,:,:)=s;
0073    R(n,:)=r;
0074 end;
0075 t=tn;
0076 S=squeeze(S); R=squeeze(R); if nargout==5; Serr=squeeze(Serr);end

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