Extract a subset of data from a trackdata object according to the label in the parallel label vector.
dextract.lab(dataset, labs, labtype = unique(labs))A trackdata object which is a subset of trackdata containing
only the data for those labels in labtype. The result has the same
components as the input trackdata:
A vector or matrix of numerical data.
A two column matrix giving the start and end indices into the data vector for each segment.
A two column matrix giving the start and end times for each segment.
A trackdata object returned from track.
A vector of labels parallel to trackdata$index, i.e. one
for each segment in the trackdata.
A vector of labels for which data is to be extracted.
track, dextract, get.time.element, frames.time