Would someone explain the append (-a) flag in v.patch? How does the append flag alter the output of v.patch?
Does it still combine vector features in a single map (by that I mean draw a small area on top of a larger area i.e. island)? or does it add a feature to a geographic region as long as there is no feature already there (by that I mean, combine area1 from map1 next to area2 from map2 on map3 as long as there is no overlap)? or would that be a job for v.overlay?
Perhaps this question is really, how do v.patch and v.overlay differ?
Thanks,
Kirk R. Wythers
Dept. of Forest Resources
University of Minnesota
email: kwythers@umn.edu
tel: 612.625.2261
fax: 612.625.5212