[GRASS-user] v.in.ascii with undefined columns?

[Markus Neteler]

On Thu, Aug 6, 2015 at 10:04 AM, patrick s. <patrick_gis at gmx.net> wrote:
> Dear all
>
> I want to import multiple csv-files with coordinates (points) that come from
> Excel/SPSS, having first row as header. These have undefined labels of
> columns

Can you please explain a bit more "undefined labels of columns"?
Is it that you don't know the column type? Or the name of them?

If the former, you can use a .csvt file in case you import from CSV.
For an example, see
https://grass.osgeo.org/grass70/manuals/db.in.ogr.html#import-csv-file

> that need to be available in grass and that might change in future.
> Running grass on dbf-backend,

As mentioned earlier: when it comes to real attribute data processing,
better use the SQLite backend:
faster, long column names etc.

> I used to create shapefiles in R and import
> these with v.in.ogr. However, this does not seem to be appropriate, when
> running grass on sqlite (abbreviation of columnnames).

Note that the SHAPE format already abbreviated it!

You may consider the Spatialite format for exchange. I just proposed
it as best option for the Rgrass7 interface (in the grass-stats
mailing list).

> There seem to be
> different solutions, but I am what is the recommended approach. Hopefully
> you can give me a hint.
>
> Thanks,
> Patrick
>
> ##Current ideas:
> #Version 0
> create shapefile in R
> (http://gis.stackexchange.com/questions/30785/how-to-stop-writeogr-from-abbreviating-field-names-when-using-esri-shapefile-d)
> import shapefile with v.in.ogr

--> since this goes "through" DBF then, the column name cutting has happened.

> #Version1
> query csv and create file "coldef" with Column definition in SQL style (in
> shell or R?)

...even in shell, see the db.in.ogr manual page for an example or the
CSV driver page of OGR.

> import in grass with v.in.ascii format=point skip=1 columns=coldef

Yes.

> #Version2
> create sqlite-file in R/OGR with SPATIALITE-extension (see
> https://stat.ethz.ch/pipermail/r-sig-geo/2014-July/021313.html)
> import in grass with v.in.ogr

Yes, best solution I think.

> (this post mentions problems
> http://gis.stackexchange.com/questions/1733/how-to-import-spatialite-data-into-grass)

... that posting is from 2010 - a lot has happened since then :-)

Markus