[GRASS5] v.patch -a

[Kirk R. Wythers]

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 at umn.edu
tel: 612.625.2261
fax: 612.625.5212