Giovanni Manghi wrote:
> > I just made a fresh install on my pc, Ubuntu 10.04 and GRASS 6.4 rc6
> > from the Ubuntugis repository.
> > It seems to me that v.in.ogr is quite slower if compared with my old
> > installation (6.4 rc5 on Ubuntu 9.04)
> >
> > for example this
> > http://thematicmapping.org/downloads/TM_WORLD_BORDERS-0.3.zip
> > takes nearly 5 minutes and before it took much less.
Markus Metz wrote:
> Here it takes nearly 30 minutes with grass64, all versions, RC5 is not
> faster than RC6 or current svn. This vector is extremely dirty,
> boundaries of adjacent polygons don't match, resulting in about 2300
> overlapping areas and about 2400 spurious areas (gaps between adjacent
> polygons) equaling about 4700 erroneous areas for only 3775 input
> polygons. Import time was reduced to 4 minutes when snapping
> boundaries during import. With snapping during import and grass7, it's
> down to 1 min 46 sec and the result is topologically clean.
> I would rather use another world boundary layer, e.g. UN FGGD from FAO
> geonetwork.
Nikos Alexandris wrote:
in grass64 (without snapping):
time v.in.ogr dsn=TM_WORLD_BORDERS-0.3.shp out=tm_world_borders_03
--%<---
3775 input polygons
Total area: 1.473113e+14 (8484 areas)
Overlapping area: 3.402229e+09 (2294 areas)
Area without category: 3.994093e+11 (2292 areas)
real 55m10.964s
user 54m50.060s
sys 0m8.040s
-->%---
in grass64 with snapping=0.1:
time v.in.ogr dsn=TM_WORLD_BORDERS-0.3.shp out=tm_world_borders_03_snapped_01
snap=0.1
--%<---
3775 input polygons
Total area: 1.480245e+14 (4647 areas)
Overlapping area: 0.000000e+00 (0 areas)
Area without category: 1.139301e+12 (1628 areas)
real 0m52.400s
user 0m49.730s
sys 0m1.250s
-->%---
in grass70 with snapping=0.1:
time v.in.ogr dsn=TM_WORLD_BORDERS-0.3.shp
out=tm_world_borders_03_grass70_snapped_01 snap=0.1
--%<---
3775 input polygons
Total area: 1.37653E+14 (4375 areas)
Overlapping area: 0 (0 areas)
Area without category: 1.11988E+12 (1475 areas)
real 0m53.130s
user 0m51.160s
sys 0m1.240s
-->%---
Nikos