e00 output

[Michel Wurtz - ENGEES/CEREG]

David D Gray wrote:
>
> corresponding to the SDTS TVP. From my reading of e00.txt analysis
> file, it seems that e00 is also one of these - ie. a `topological'
> format, not a `geometric' one like shapefile or MI?

Yes, e00 can include all topological links, even if you can also
export "spagghetti" vector files in e00.  This is the reason why it
was not to complicated to import e00 files (once you know how the
topology is coded), and it's probably not impossible to export
Grass vector file in e00 format.

In fact Grass topology (in dig_plus files) is pretty close from
ESRI idea of topology : lines should be connected by nodes, polygons
are defined by a list of arc and/or a label point inside and share
border lines (no duplication as in shape, etc...).  Each line has
a node at its beginning and at its end, and a left and a right polygon.

The actual version of m.in.e00 didn't get all thoses information,
so you have to run v.support after import.  A futur development
could be the reconstruction of the topology directly from e00
indications (even if you have to verify that it isn't garbled ;-)

-- 
Michel Wurtz    ENGEES - CEREG
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