[GRASS-user] Filling holes in polygons

[Hamish]

Jaros³aw Jasiewicz wrote:
> The problem is simple:
> If I want to remove small single areas I use v.to.db to upload areas to 
> database and next extract poligons with area grater than thereeshols
> 
> But how to perform opposite operation:
> I have polygnos with some holes. I would like remove the smalllest (not 
> all)


the task is to remove small holes, correct?

the vector engine can certainly do it, but I don't know what module frontend to
them could do it. some ideas:

'v.clean tool=rmarea' may help to remove small areas 

if you could give the holes centroids you could v.clean remove small areas +
create a error= map, then use v.overlay to wipe out from the original?
v.dissolve to get rid of left over boundaries (v.distance to set hole's cat
from nearest area first?)

The SQL approach is interesting.

run v.buffer then see which features disappear?

note GRASS sometimes calls holes in areas "islands".


Hamish



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