[GRASS5] Re: [GRASSLIST:7685] 90% of ESRI SHP file lost

[Hamish]

On July 22, 2005:
> history: this is closely related to message [7683], similar warnings
> and errors
> 
> vitals:
> gentoo linux-2.6.11-gentoo-r5
> grass 6.1
> compiled
> 
> some of the output:
> ----------------------------------
> GRASS_INFO_WARNING(10881,12): Area size 1.1e-07, area not imported.
> Area size 4.5e-06, area not imported.
> 
> File info:
> ---------------
> polygon shape file working fine in Arcview 3.2
> used OGR to set wgs84
> imported into GRASS
> warnings and sreaming
> when the file loads only some the polygons appear and the others are
> gone this happened to two or three files in the same project.
> All others (8 to 10 files) were not affected


[sorry for the very late response, but maybe someone searches the
archives for the same answer...]


Simply reduce the min_area threshold in v.in.ogr.

  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


With a lat/lon location as you seem to be using, 0.0001 of a degree 
is about 3m x 3m, and reasonably sized features get lost. I guess the
bug is that the default value is assuming that the unit is meters.
Should probably be filed as a bug report.


Hamish