CinePlex v3 Manual - Plexon Inc

5
marker, but the tool displays information that helps to determine the extent to
which the periodicity assumption is valid.
When a marker is selected, the algorithm analyses the times of the occurrences
for that marker, and displays the results in the two list boxes. The algorithm can
use or ignore the results of this analysis, depending on the following Timestamp
Determination selections. The analysis proceeds as follows:
1 Consider each pair of adjacent times for the marker occurrences, and calculate
the time difference between each pair. The number of pairs appears in the
left list box.
2 Find the min, max, average, and standard deviation on the set of calculated
time differences. Display this information in the Periodicity list box as avg =
for the average time difference, stddev = for the standard deviation around
the average time difference, min = and max = for the smallest and largest
time differences encountered.
3 Assume that any difference between adjacent occurrences that is larger than
1.1 times the average time difference constitutes a gap, or a skipped occurrence.
Using this definition of a gap, compute and display a histogram of the
sizes of the gaps in the Gap Sizes list box. The 0: line in this list box is to be
interpreted as the number of timestamp pairs for which there were no gaps or
missing timestamps between them. The next 1: line is the number of timestamp
pairs for which there was a gap of 1 missing timestamp between the
pair, and so on.
4 By ignoring the gaps, compute a new average time difference between adjacent,
gap = 0 timestamp pairs. Display this as non-gap avg = in the Periodicity
list box. Whereas the avg = value has factored in the gaps and thus
produced a larger average time difference, the non-gap avg = has taken out
the gaps, and so produces a smaller and in many cases more accurate estimate
of the true periodicity. In effect, this is the periodicity that would be seen if it
weren't for missing samples (gaps) in the occurrences.
5.3.7.7 Mark All Waveforms As Valid
This item re-validates any waveforms that were invalidated with the Interval
Operations tool; see “Interval Operations” on page 258.
5.3.7.8 Options
This item opens the Options dialog box with several tabs as described in the following
sections.
264 CinePlex