Home > chronux > spectral_analysis > pointbinned > mtspecgrampb.m

# mtspecgrampb

## PURPOSE Multi-taper time-frequency spectrum - binned point process

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

## DESCRIPTION ``` Multi-taper time-frequency spectrum - binned point process

Usage:

[S,t,f,R,Serr]=mtspecgrampb(data,movingwin,params,fscorr)
Input:
data        (in form samples x channels/trials or single vector) -- 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 one of the following
forms:
(1) A numeric vector [TW K] where TW is the
time-bandwidth product and K is the number of
tapers to be used (less than or equal to
2TW-1).
(2) A numeric vector [W T p] where W is the
bandwidth, T is the duration of the data and p
is an integer such that 2TW-p tapers are used. In
this form there is no default i.e. to specify
the bandwidth, you have to specify T and p as
well. Note that the units of W and T have to be
consistent: if W is in Hz, T must be in seconds
and vice versa. Note that these units must also
be consistent with the units of params.Fs: W can
be in Hz if and only if params.Fs is in Hz.
The default is to use form 1 with TW=3 and K=5
Note that T has to be equal to movingwin(1).

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
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/channnels 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       (spectrum in form time x frequency x channels/trials for trialave=0;
or as a function of frequency if trialave=1)
t       (times)
f       (frequencies)
R       (rate)
Serr    (error bars) - only for err(1)>=1```

## CROSS-REFERENCE INFORMATION This function calls:
This function is called by:
• mtspecgramtrigpb Multi-taper event triggered time-frequency spectrum - binned point process

## SOURCE CODE ```0001 function [S,t,f,R,Serr]=mtspecgrampb(data,movingwin,params,fscorr)
0002 % Multi-taper time-frequency spectrum - binned point process
0003 %
0004 % Usage:
0005 %
0006 % [S,t,f,R,Serr]=mtspecgrampb(data,movingwin,params,fscorr)
0007 % Input:
0008 %       data        (in form samples x channels/trials or single vector) -- 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 one of the following
0015 %                    forms:
0016 %                   (1) A numeric vector [TW K] where TW is the
0017 %                       time-bandwidth product and K is the number of
0018 %                       tapers to be used (less than or equal to
0019 %                       2TW-1).
0020 %                   (2) A numeric vector [W T p] where W is the
0021 %                       bandwidth, T is the duration of the data and p
0022 %                       is an integer such that 2TW-p tapers are used. In
0023 %                       this form there is no default i.e. to specify
0024 %                       the bandwidth, you have to specify T and p as
0025 %                       well. Note that the units of W and T have to be
0026 %                       consistent: if W is in Hz, T must be in seconds
0027 %                       and vice versa. Note that these units must also
0028 %                       be consistent with the units of params.Fs: W can
0029 %                       be in Hz if and only if params.Fs is in Hz.
0030 %                       The default is to use form 1 with TW=3 and K=5
0031 %                   Note that T has to be equal to movingwin(1).
0032 %
0033 %            pad            (padding factor for the FFT) - optional (can take values -1,0,1,2...).
0034 %                    -1 corresponds to no padding, 0 corresponds to padding
0035 %                    to the next highest power of 2 etc.
0036 %                       e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
0037 %                       to 512 points, if pad=1, we pad to 1024 points etc.
0038 %                       Defaults to 0.
0039 %           Fs   (sampling frequency) - optional. Default 1.
0040 %           fpass    (frequency band to be used in the calculation in the form
0041 %                                   [fmin fmax])- optional.
0042 %                                   Default all frequencies between 0 and Fs/2
0043 %           err  (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars
0044 %                                   [0 p] or 0 - no error bars) - optional. Default 0.
0045 %           trialave (average over trials/channnels when 1, don't average when 0) - optional. Default 0
0046 %       fscorr   (finite size corrections, 0 (don't use finite size corrections) or
0047 %                1 (use finite size corrections) - optional
0048 %                (available only for spikes). Defaults 0.
0049 % Output:
0050 %       S       (spectrum in form time x frequency x channels/trials for trialave=0;
0051 %               or as a function of frequency if trialave=1)
0052 %       t       (times)
0053 %       f       (frequencies)
0054 %       R       (rate)
0055 %       Serr    (error bars) - only for err(1)>=1
0056
0057 if nargin < 2; error('Need data and window parameters'); end;
0058 if nargin < 3; params=[]; end;
0059
0061 if length(params.tapers)==3 & movingwin(1)~=params.tapers(2);
0062     error('Duration of data in params.tapers is inconsistent with movingwin(1), modify params.tapers(2) to proceed')
0063 end
0064
0065 if nargin < 4 || isempty(fscorr); fscorr=0; end;
0066 if nargout > 4 && err(1)==0;
0067 %    error('Cannot compute errors with err(1)=0');
0068      error('When Serr is desired, err(1) has to be non-zero.');
0069 end;
0070 data=change_row_to_column(data);
0071 [N,Ch]=size(data);
0072 Nwin=round(Fs*movingwin(1)); % number of samples in window
0073 Nstep=round(movingwin(2)*Fs); % number of samples to step through
0075 f=getfgrid(Fs,nfft,fpass); Nf=length(f);
0076 params.tapers=dpsschk(tapers,Nwin,Fs); % check tapers
0077 winstart=1:Nstep:N-Nwin+1;
0078 nw=length(winstart);
0079 if trialave
0080     S = zeros(nw,Nf);
0081     R = zeros(nw,Nwin);
0082     if nargout==4; Serr=zeros(2,nw,Nf); end;
0083 else
0084     S = zeros(nw,Nf,Ch);
0085     R = zeros(nw,Nwin,Ch);
0086     if nargout==4; Serr=zeros(2,nw,Nf,Ch); end;
0087 end
0088
0089 for n=1:nw;
0090    indx=winstart(n):winstart(n)+Nwin-1;
0091    datawin=data(indx,:);
0092    if nargout==5;
0093      [s,f,r,serr]=mtspectrumpb(datawin,params,fscorr);
0094      Serr(1,n,:,:)=squeeze(serr(1,:,:));
0095      Serr(2,n,:,:)=squeeze(serr(2,:,:));
0096    else
0097      [s,f,r]=mtspectrumpb(datawin,params,fscorr);
0098    end;
0099    S(n,:,:)=s;
0100    R(n,:)=r';
0101 end;
0102 winmid=winstart+round(Nwin/2);
0103 t=winmid/Fs;
0104 S=squeeze(S); R=squeeze(R); if nargout==5; Serr=squeeze(Serr);end```

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