Seb wrote:
So IIUC, it's not possible to keep attributes for each point along a
lines vector, so that one can select points along a line that meet
certain criteria.
no, vertices can not have cats, only one cat (DB key index) per line.
you need two maps: one with the line, another with the vertices as points.
see the v.in.garmin, v.in.gpsbabel scripts for importing tracks or
"tracks as points".
For example, to be able to show (or do calculations) a line joining
points that are have values "A" in column 3 and values "Z" in column 4.
v.extract where='col3 = 'A' AND col4 = 'Z'
v.out.ascii | v.in.mapgen
?
but do worry about the order of points; try to sort by cat (if sequentially
added) or by timestamp. otherwise you will have lines going everywhere in
a big mess.
Hamish