Home > chronux > spectral_analysis > pointtimes > mtspectrumtrigpt.m

# mtspectrumtrigpt

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

## SYNOPSIS function [S,f,R,Serr]=mtspectrumtrigpt(data,E,win,params,fscorr)

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

Usage:

[S,f,R,Serr]=mtspectrumtrigpt(data,E,win,params,fscorr)
Input:
data        (structure array of one channel of spike times;
also accepts 1d column vector of spike times) -- required
E           (event times) - required
win         (in the form [winl winr] i.e window around each event)--
required
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

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 events when 1, don't average when 0) -
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       (triggered spectrum in form frequency x events if trialave=0;
function of frequency if trialave=1)
f       (frequencies)
R       (spike rate)
Serr    (error bars) - only for err(1)>=1```

## CROSS-REFERENCE INFORMATION This function calls:
• createdatamatpt Helper function to create an event triggered matrix from a single
• mtspectrumpt Multi-taper spectrum - point process times
This function is called by:

## SOURCE CODE ```0001 function [S,f,R,Serr]=mtspectrumtrigpt(data,E,win,params,fscorr)
0002 % Multi-taper time-frequency spectrum - point process times
0003 %
0004 % Usage:
0005 %
0006 % [S,f,R,Serr]=mtspectrumtrigpt(data,E,win,params,fscorr)
0007 % Input:
0008 %       data        (structure array of one channel of spike times;
0009 %                   also accepts 1d column vector of spike times) -- required
0010 %       E           (event times) - required
0011 %       win         (in the form [winl winr] i.e window around each event)--
0012 %                                                 required
0013 %       params: structure with fields tapers, pad, Fs, fpass, err, trialave
0014 %       - optional
0015 %           tapers : precalculated tapers from dpss or in the one of the following
0016 %                    forms:
0017 %                   (1) A numeric vector [TW K] where TW is the
0018 %                       time-bandwidth product and K is the number of
0019 %                       tapers to be used (less than or equal to
0020 %                       2TW-1).
0021 %                   (2) A numeric vector [W T p] where W is the
0022 %                       bandwidth, T is the duration of the data and p
0023 %                       is an integer such that 2TW-p tapers are used. In
0024 %                       this form there is no default i.e. to specify
0025 %                       the bandwidth, you have to specify T and p as
0026 %                       well. Note that the units of W and T have to be
0027 %                       consistent: if W is in Hz, T must be in seconds
0028 %                       and vice versa. Note that these units must also
0029 %                       be consistent with the units of params.Fs: W can
0030 %                       be in Hz if and only if params.Fs is in Hz.
0031 %                       The default is to use form 1 with TW=3 and K=5
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 events when 1, don't average when 0) -
0046 %           default 0
0047 %       fscorr   (finite size corrections, 0 (don't use finite size corrections) or
0048 %                1 (use finite size corrections) - optional
0049 %                (available only for spikes). Defaults 0.
0050 %
0051 % Output:
0052 %       S       (triggered spectrum in form frequency x events if trialave=0;
0053 %               function of frequency if trialave=1)
0054 %       f       (frequencies)
0055 %       R       (spike rate)
0056 %       Serr    (error bars) - only for err(1)>=1
0057
0058 if nargin < 3; error('Need data, events and window parameters'); end;
0059 if nargin < 2; params=[]; end;