[Qgis-user] Re: [GRASS-user] Problem importing/viewing a ~160MB shapefile

[Nikos Alexandris]

On Sat, 2008-11-29 at 15:12 +0100, Nikos Alexandris wrote:
> On Mon, 2008-10-13 at 17:07 -0700, Hamish wrote:
> > Nikos Alexandris wrote:
> > > Dear All, apologies for the cross-posting but I have trouble to work
> > > with a BIG shapefil (~160MB). I already used that shapefile in the past
> > > without problems. But now I can't use it.
> > 
> > ? what changed?  did you install a new version of GDAL/OGR?
> > I use 400mb shapefiles without problem..
> > 
> >  
> > > In GRASS: I (almost) managed to import in GRASS this BIG shapefile but
> > > the process *stucks* somewhere at "breaking intersections" point (...it
> > > was running for 10 hours). I broke the process and the file was in
> > > GRASS' database. I run v.build but it still is problematic. I can't get
> > > anything on-display.
> > 
> > It just takes a long time when lines are very long and unbroken. It
> > eventually gets there.
> > 
> > See Radim's vector TODO:
> >   http://trac.osgeo.org/grass/browser/grass/trunk/doc/vector/TODO#L242
> > 
> > and search the archives for the "Florida Coastline" problem.
> > 
> > 
> > the v.in.ogr spatial= option might help.
> > 
> > 
> > > In QGIS: when I try to load directly the shapefile (not the GRASS
> > > vector) my system freezes!! I haven't seen my linuxbox frozen since I
> > > don't remember when. What could cause such behaviour?
> > > Is there anyway to get the shapefile fixed out of GRASS?
> > 
> > once loaded into GRASS you can run the v.split command to split the long
> > lines, then it is much faster (at least for other grass commands).
> > 
> > 
> > Hamish
> 
> Hamish and all,
> back to this "old" post.
> 
> ********
> Attemp 1
> ********
> # using gdal 1.5.3, grass6_devel
> # import shapefile
> v.in.ogr dsn=... out=...
> # buffer overflow error (or segfault --- I can't recall).
> 
> 
> ********
> Attemp 2
> ********
> # using gdal-1.6.0beta2, grass6_devel
> # importing the usual way
> v.in.ogr dsn=coastlines.shp out=coastlines_longtime -ew --o
> 
> Projection of input dataset and current location appear to match
> Layer: coastlines
> WARNING: Column name changed: 'AREA' -> 'area'
> WARNING: Column name changed: 'PERIMETER' -> 'perimeter'
> [...]
> Importing map 181148 features...
> -----------------------------------------------------
> Building topology for vector map <global_coastlines_longtime>...
> Registering primitives...
> 181386 primitives registered
> 9764427 vertices registered
> Building areas...
>  100%
> 181386 areas built
> 181386 isles built
> Attaching islands...
>  100%
> Attaching centroids...
>  100%
> Number of nodes: 181386
> Number of primitives: 181386
> Number of points: 0
> Number of lines: 0
> Number of boundaries: 181386
> Number of centroids: 0
> Number of areas: 181386
> Number of isles: 181386
> Number of areas without centroid: 181386
> -----------------------------------------------------
> WARNING: Cleaning polygons, result is not guaranteed!
>  100%
> Building topology for vector map <global_coastlines_longtime>...
> Number of nodes: 181386
> Number of primitives: 181386
> Number of points: 0
> Number of lines: 0
> Number of boundaries: 181386
> Number of centroids: 0
> Number of areas: -
> Number of isles: -
> -----------------------------------------------------
> Break polygons:
> ^[^[-----------------------------------------------------
> Remove duplicates:
> -----------------------------------------------------
> Break boundaries:
> 
> # file get's imported and, as it can be seen from the output "breaking
> polygons" and "removing duplicates" is successful
> # the "^[^[" characters was me pressing something to check whether the
> system is still running or not
> # breaking boundaries is still there even after more than 30 hours!
> 
> 
> ********
> Attemp 3
> ********
> # v.in.ogr -c ## takes some time but is successful
> 
> # v.split (vertices=3) ## I have really no idea which number is
> appropriated depending on what. ### it works
> 
> # v.clean tool=break ## never ends or it might need more than 2-3 days!?
> 
> 
> I can open the file with QGIS preview (unstable) but not with QGIS
> 0.11.0. The latter freezes the whole system, as I have reported in my
> first post about this.
> 
> Regards, Nikos

Once again apologies for cross-posting. I face this strange behaviour:

While QGIS (unstable, revision 9711) can open and report GRASS' region
setting for a lat-long location and load/view the above mentioned
"coastline" dataset (both the shapefile and the GRASS vector, the one
after v.in.ogr -c and NOT after v.clean!!), GRASS reports the error:

g.region -p
ERROR: default region is invalid
       line 4: <south: 90:22:00.17015S>

No matter what I do (even "g.region help") GRASS gives this error. From
within QGIS, the "Edit current regions settings" dialog seems to just
work. However, I cannot use any g.region.* tool from QGIS'
GRASS-Toolbox.

Shrug!!