Home > chronux_1_50 > pointtimes > mtdspecgrampt.m

mtdspecgrampt

PURPOSE ^

Multi-taper derivative time-frequency spectrum - point process times

SYNOPSIS ^

function [dS,t,f]=mtdspecgrampt(data,movingwin,phi,params)

DESCRIPTION ^

 Multi-taper derivative time-frequency spectrum - point process times

 Usage:

 [dS,t,f]=mtdspecgrampt(data,movingwin,phi,params)
 Input: 
   Note that all times can be in arbitrary units. But the units have to be
   consistent. So, if E is in secs, win, t have to be in secs, and Fs has to
   be Hz. If E is in samples, so are win and t, and Fs=1. In case of spike
   times, the units have to be consistent with the units of data as well.
       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.
                                                 Note that units here have
                                                 to be consistent with
                                                 units of Fs
       phi         (angle for evaluation of derivative) -- required.
                       e.g. phi=[0,pi/2] giving the time and frequency
                       derivatives
       params: structure with fields tapers, pad, Fs, fpass, 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 (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
           trialave (average over trials when 1, don't average when 0) -
           optional. Default 0
 Output:
       dS      (spectral derivative in form phi x time x frequency x channels/trials if trialave=0; in form phi x time x frequency if trialave=1)
       t       (times)
       f       (frequencies)

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [dS,t,f]=mtdspecgrampt(data,movingwin,phi,params)
0002 % Multi-taper derivative time-frequency spectrum - point process times
0003 %
0004 % Usage:
0005 %
0006 % [dS,t,f]=mtdspecgrampt(data,movingwin,phi,params)
0007 % Input:
0008 %   Note that all times can be in arbitrary units. But the units have to be
0009 %   consistent. So, if E is in secs, win, t have to be in secs, and Fs has to
0010 %   be Hz. If E is in samples, so are win and t, and Fs=1. In case of spike
0011 %   times, the units have to be consistent with the units of data as well.
0012 %       data        (structure array of spike times with dimension channels/trials; also accepts 1d array of spike times) -- required
0013 %       movingwin         (in the form [window winstep] i.e length of moving
0014 %                                                 window and step size.
0015 %                                                 Note that units here have
0016 %                                                 to be consistent with
0017 %                                                 units of Fs
0018 %       phi         (angle for evaluation of derivative) -- required.
0019 %                       e.g. phi=[0,pi/2] giving the time and frequency
0020 %                       derivatives
0021 %       params: structure with fields tapers, pad, Fs, fpass, trialave
0022 %       -optional
0023 %           tapers (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not
0024 %                                                 specified, use [NW K]=[3 5]
0025 %            pad            (padding factor for the FFT) - optional (can take values -1,0,1,2...).
0026 %                    -1 corresponds to no padding, 0 corresponds to padding
0027 %                    to the next highest power of 2 etc.
0028 %                       e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
0029 %                       to 512 points, if pad=1, we pad to 1024 points etc.
0030 %                       Defaults to 0.
0031 %           Fs   (sampling frequency) - optional. Default 1.
0032 %           fpass    (frequency band to be used in the calculation in the form
0033 %                                   [fmin fmax])- optional.
0034 %                                   Default all frequencies between 0 and
0035 %                                   Fs/2
0036 %           trialave (average over trials when 1, don't average when 0) -
0037 %           optional. Default 0
0038 % Output:
0039 %       dS      (spectral derivative in form phi x time x frequency x channels/trials if trialave=0; in form phi x time x frequency if trialave=1)
0040 %       t       (times)
0041 %       f       (frequencies)
0042 
0043 if nargin < 3; error('Need data, window parameters and angle'); end;
0044 if nargin < 4; params=[]; end;
0045 [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params);
0046 clear err 
0047 [mintime,maxtime]=minmaxsptimes(data);
0048 tn=(mintime+movingwin(1)/2:movingwin(2):maxtime-movingwin(1)/2);
0049 Nwin=round(Fs*movingwin(1)); % number of samples in window
0050 % Nstep=round(movingwin(2)*Fs); % number of samples to step through
0051 nfft=max(2^(nextpow2(Nwin)+pad),Nwin);
0052 f=getfgrid(Fs,nfft,fpass); Nf=length(f);
0053 params.tapers=dpsschk(tapers,Nwin,Fs); % check tapers
0054 %K=size(params.tapers,2);
0055 nw=length(tn);
0056 if trialave==0; dS=zeros(length(phi),nw,Nf,C); else dS=zeros(length(phi),nw,Nf); end;
0057 for n=1:nw;
0058    t=linspace(tn(n)-movingwin(1)/2,tn(n)+movingwin(1)/2,Nwin);
0059    datawin=extractdatapt(data,[t(1) t(end)]);
0060    [ds,f]=mtdspectrumpt(datawin,phi,params,t);
0061    dS(:,n,:,:)=ds;
0062 end;
0063 sz=size(ds);
0064 dS=squeeze(dS);
0065 % if length(sz)==3;
0066 %    dS=permute(dS,[2 1 3 4]);
0067 % elseif length(phi)>1
0068 %    dS=permute(dS,[2 1 3]);
0069 % end;
0070 t=tn;

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