Identify lines that are pointsSource:
OD matrices often contain 'intrazonal' flows, where the origin is the same point as the destination. This function can help identify such intrazonal OD pairs, using 2 criteria: the total number of vertices (2 or fewer) and whether the origin and destination are the same.
Returns a boolean vector. TRUE means that the associated line is in fact a point (has no distance). This can be useful for removing data that will not be plotted.