Finds the time and position of a data element.
frames.time(dataset, datanum)A dataset returned by track or frames.
An integer, an index into the data component of
dataset.
The segment number which contains the element datanum of
dataset$data.
The dataset returned from track or frames consists of a
matrix of data (the data component) and two index components
(index and ftime). The data for all segments is concatenated
together in $data. This function can be used to find out which
segment a particular row of $data corresponds to.
track, frames