Home > chronux_code > exploratory > correlations > continuous > mtdspecgramc.m

mtdspecgramc

PURPOSE ^

Multi-taper derivative of the time-frequency spectrum - continuous process

SYNOPSIS ^

function [dS,t,f]=mtdspecgramc(data,movingwin,tapers,phi,pad,Fs,fpass,trialave)

DESCRIPTION ^

 Multi-taper derivative of the time-frequency spectrum - continuous process

 Usage:

 [dS,t,f]=mtdspecgramc(data,movingwin,tapers,phi,pad,Fs,fpass,trialave)
 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.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [dS,t,f]=mtdspecgramc(data,movingwin,tapers,phi,pad,Fs,fpass,trialave)
0002 % Multi-taper derivative of the time-frequency spectrum - continuous process
0003 %
0004 % Usage:
0005 %
0006 % [dS,t,f]=mtdspecgramc(data,movingwin,tapers,phi,pad,Fs,fpass,trialave)
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 
0013 %       data        (in form samples x channels/trials) -- required
0014 %       movingwin         (in the form [window winstep] i.e length of moving
0015 %                                                 window and step size.
0016 %                                                 Note that units here have
0017 %                                                 to be consistent with
0018 %                                                 units of Fs
0019 %       tapers      (precalculated tapers from dpss, or in the form [NW K] e.g [3 5]) -- optional. If not
0020 %                                                 specified, use [NW K]=[3 5]
0021 %       phi         (angle for evaluation of derivative) -- optional.
0022 %                       Default phi=[0,pi/2] giving the time and frequency
0023 %                       derivatives
0024 %        pad            (padding factor for the FFT) - optional. Defaults to 0.
0025 %                         e.g. For N = 500, if PAD = 0, we pad the FFT
0026 %                         to 512 points; if PAD = 2, we pad the FFT
0027 %                         to 2048 points, etc.
0028 %       Fs          (sampling frequency) - optional. Default 1.
0029 %       fpass       (frequency band to be used in the calculation in the form
0030 %                                   [fmin fmax])- optional.
0031 %                                   Default all frequencies between 0 and Fs/2
0032 %       trialave    (average over trials when 1, don't average when 0) - optional. Default 0
0033 % Output:
0034 %       dS       (spectrum in form angle x time x frequency x channels/trials)
0035 %       t       (times)
0036 %       f       (frequencies)
0037 
0038 if nargin < 2; error('Need data and window parameters'); end;
0039 if nargin < 3; tapers=[3 5]; end;
0040 if nargin < 4; phi=[0 pi/2];end;
0041 if nargin < 5;pad=0;end;
0042 if nargin < 6; Fs=1; end;
0043 if nargin < 7; fpass=[0 Fs/2]; end;
0044 if nargin < 8; trialave=0; end;
0045 
0046 N=size(data,1);
0047 Nwin=round(Fs*movingwin(1)); % number of samples in window
0048 Nstep=round(movingwin(2)*Fs); % number of samples to step through
0049 nfft=2^(nextpow2(Nwin)+pad);
0050 f=getfgrid(Fs,nfft,fpass); 
0051 tapers=dpsschk(tapers,Nwin,Fs); % check tapers
0052 
0053 winstart=1:Nstep:N-Nwin+1;
0054 nw=length(winstart);
0055 for n=1:nw;
0056    indx=winstart(n):winstart(n)+Nwin-1;
0057    datawin=data(indx,:);
0058    [ds,f]=mtdspectrumc(datawin,tapers,phi,pad,Fs,fpass,trialave);
0059    dS(n,:,:,:)=ds;
0060 end;
0061 sz=size(ds);
0062 if length(sz)==3;
0063    dS=permute(dS,[2 1 3 4]);
0064 else
0065    dS=permute(dS,[2 1 3]);
0066 end;
0067 winmid=winstart+round(Nwin/2);
0068 t=winmid/Fs;

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