[GRASS-dev] v.split: what is 'vertices' for?

Hamish hamish_nospam at yahoo.com
Thu Oct 5 02:53:54 EDT 2006

Maciej Sieczka wrote:
> I haven't found anything relevant in the manual, lists archives, the
> BT or the source code, so I'm asking here.
> There are 2 vertices (nodes) currently. Trying to add a vertex between
> them:
> $ v.split input=line output=line_split vertices=3
> Checking line_split in v.digit proves there are still only 2 vertices
> - the nodes themselves; the 3rd vertex in not added.
> No matter what is the 'vertices' set to, the outcome is the same. Is
> that OK? What am I missing to understand what is the 'vertices' option
> for?

v.split is acting correctly. As usual, more documentation needed.

The module breaks lines at verticies, it doesn't add verticies.

In Radim's vector TODO there is a bit about v.in.ogr needing v.split
built into it for huge polygons.

e.g., I have a long, high-resolution single boundary line of the
coastline. Some tools take a very long time to process (build) this. By
using v.split to break the same polygon into several connected boundary
lines (green "X" in v.digit) you can speed up processing 1000%.


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