## Post event scan

Purpose
Description
Tips
Macro Synopsis
Modules
Related Functions
References

### Purpose

Peak-triggered post event scan.

### Description

"Post event scan" is the time-resolving Post Event Time Histogram of the probe signal x with respect to the peaks of a trigger signal trig. The columns of the 2-dimensional Post event scan, consist of the values of x, starting at one of the trigger times , respectively:

The trigger time is defined as the i-th peak of the trigger signal trig.
The Parameters are:
• window size (time interval) in x-axis units ws
For a detailed description of this parameter, refer to Peak-to-peak intervals.
• peakt, the type of peaks, which is either
• "Maxima" (0) or
• "Minima" (1),
• cross, determining whether a threshold crossing between peaks is
• "not checked" (0) or
• "checked" (1)
If this is turned on (1), the function only detects a peak if the threshold line has been crossed by the signal after the previous peak,
• threshold thresh for the detection of peaks,
• time delay tau for the scan offset ( in the formula above),
• time resolution tres (number of columns of the output),
• scan resolution scres (number of lines of the output)

The result is a 2D output signal, exhibiting rhythms in the probe signal as well as the degree of synchronisation (phase relation) between trigger and probe.

### Tips

To examine the synchronisation of two rhythms take the signal with the slower rhythmic activity as the trigger signal to let the oscillations of the "faster'' signal produce distinct structures along the ordinate. If these patterns are stable along the time axis the rhythms exhibit a phase synchronisation.

### Macro Synopsis

y = PostEventScan([trig,x],ws,peakt,cross,thresh,tau,tres,scres);
signal trig,x,y;
float ws;
option peakt, cross;
float thresh;
int tres, scres;

Note that y is a 2D signal.

Nonlinear

### Related Functions

Conditional coupling divergence (PCCD), Delta test, Mutual cross information, Pointwise transinformation, Synchronicity histogram, Transinformation, Post event time histogram, Peak-to-peak intervals.

### References

Vandenhouten [21]