[GRASS-user] Having problems with v.in.ogr

[Hamish]

Edward Tomlinson wrote:
> I am having issues importing a shapefile using v.in.ogr
> 
> Using basic command v.in.ogr dsn=shapefile layer=shapefile name
> output=elev
> 
> getting the following areas for every entry
> 
> GRASS_INFO_WARNING(29..,50..): Area size 6.5e-11, area not imported.
> ...
> [warning sign] area size 6.5e-11, area not imported
> ...

Reduce v.in.ogr's min_area option.

  min_area   Minimum size of area to be imported (square units).
             Smaller areas and islands are ignored. Should be
             greater than snap^2
             default: 0.0001

 
> THe shapefile was generated by a Greenstar 2 GPS receiver (John
> Deere).

could you make a small sample available somewhere?


> There are many columns in the shapefile (30).
> 
> How can i limit the number of columns i read in,

you can't during import, but you can later with v.db.dropcol

> and how to set which column is the elevation column (or is ELEVATION
> okay)?

I am not sure if there is a vector tool to change a 2D vector + numeric
column into a 3D vector directly.
v.out.ascii + "v.in.ascii z=" would probably do it.

but most GRASS DEM creation tools will let you specify a 2D vector + elev
column name instead of needing a 3D vector as the input.


> I am assuming it has something to do with the way the shapefile was
> genereated and the precision/length of the numeric fields in the
> database???

As long as the datafile is not corrupt you /should/ be able to work with
whatever is in it.


> Also what is a good .dbf viewer for KDE?

Don't know about KDE, but "dbview -bt" is nice from the command line, and
OpenOffice is probably ok if there are less than a few tens of thousands of
entries.


Hamish