[GRASS-dev] change in vector area format?

[Michael Barton]

Thanks for the explanation. I won't worry about running v.build in  
GRASS 7 then. Somewhere along the line, we could probably use a script  
that automatically runs v.build on all vectors in a mapset to build  
the file based spatial index.

BTW, I'm glad to see interest in my v.what suggestions. These were an  
important component of a set of suggestions to standardize and enhance  
vector processing.

Best
Michael


On Dec 15, 2009, at 6:06 AM, Markus Metz wrote:

>
> Michael Barton wrote:
>> Maybe I just missed the announcement. But I was surprised to find  
>> that
>> areas no longer displayed as areas in GRASS 7, but only as  
>> boundaries.
>> After trying multiple vector area files and considerable futzing with
>> various settings I got an error that said that the topology was bad.
>> When I rebuilt topology I could again display areas.
>>
>> Does this rebuilding of vector areas under GRASS 7 have any negative
>> repercussions for displaying the same files in GRASS 6?
> Up to now, grass7 vectors are fully compatible with grass6 vectors:
> grass6 can work with grass7 vectors. Not the other way around, because
> in grass7, the spatial index is again file-based, not built on the  
> fly.
> Consequently, grass7 can open a grass6 vector only on level 1 (no  
> topo)
> and areas are not available until topo has been rebuilt.
>
> This change was submitted to trunk on July 13 2009 as r38385, see also
> [1]. The announcement is here [2].
>
> We could change grass7 behaviour to built sidx on the fly if it is not
> available, but that defeats the purpose of the file-based spatial  
> index.
> Just run v.what on a larger vector map once in grass6 and once in  
> grass7
> after rebuilding topo, elev_lid792_bepts in nc_spm_08 is a good  
> example.
> Your suggestions about additional functionality in v.what would also
> heavily profit from it (is on my todo list...).
>
> Markus M
>
> [1] https://trac.osgeo.org/grass/wiki/Grass7/VectorLib
> [2] http://lists.osgeo.org/pipermail/grass-dev/2009-July/045098.html
>
>