My advise is to use PostGIS first, then read the summaries into R for
analysis.

THK


On Thu, Oct 17, 2013 at 8:42 AM, philippe massicotte <
pmassicotte@hotmail.com> wrote:

> For information, I'm not a the step of statistical analyses. I'm currently
> working to extract the needed data. I have several hundred points around
> the world for which I want to extract some information from these large
> shapefiles.
>
> > Date: Thu, 17 Oct 2013 14:51:24 +0200
> > From: Roger.Bivand@nhh.no
> > To: pmassicotte@hotmail.com
> > CC: mdsumner@gmail.com; r-sig-geo@r-project.org
> > Subject: Re: [R-sig-Geo] Long time to load shapefiles
> >
> > On Thu, 17 Oct 2013, philippe massicotte wrote:
> >
> > > Thank you everyone for your answers. I think I'll just load it and save
> > > the workspace for further uses. I still wonder why this is taking such
> > > long time to load whereas in QGIS or ArcGIS it is a matter of seconds.
> >
> > Why do you wonder? You could check instead, taking subsets of the fields,
> > and subsets of the features in your object. You could also use
> alternative
> > formats, but I don't think that the choice of driver is important here.
> > Note that few statisticians would consider global analysis of data sets
> > this large sensible unless very specific conditions were met; the
> > additional variability after the first several thousand observations
> > probably doesn't tell you much. Once the data are converted to sp
> classes,
> > things go rather faster, as has been pointed out.
> >
> > Roger
> >
> > > Have a great day,Phil
> > >
> > >> Date: Thu, 17 Oct 2013 17:19:39 +1100
> > >> Subject: Re: [R-sig-Geo] Long time to load shapefiles
> > >> From: mdsumner@gmail.com
> > >> To: pmassicotte@hotmail.com
> > >> CC: r-sig-geo@r-project.org
> > >>
> > >> I have a similar spec to yours, with i7 instead.
> > >>
> > >> I have successfully read it, but first time it crashed (I think
> > >> because memory was exhausted).
> > >>
> > >> It took about 20min.
> > >>
> > >> I would work on subsetting the part you want with an ogr2ogr
> > >> incantation if you want to stay away from GIS:
> > >> http://www.gdal.org/ogr2ogr.html
> > >>
> > >> QGIS or similar would be able to read / crop this no-sweat, but it
> > >> depends on exactly how you want to subset it, and that may be a topic
> > >> for another forum
> > >>
> > >> Cheers, Mike
> > >>
> > >> On Thu, Oct 17, 2013 at 2:18 AM, philippe massicotte
> > >> <pmassicotte@hotmail.com> wrote:
> > >>> Hi everyone.
> > >>> I'm trying to open some shapefiles, but the process is still not
> complete after 25 minutes.  Looking at the shapefiles in ArcGIS, I find
> that these files have roughly 500K entries. I was wondering if this
> processing time to open the shapefiles is normal. Here is my configuration:
> > >>> Intel i5-2500 @ 3.3 GHz16 GB of RAMWindows 7 (64 bits)
> > >>> For information, you can download the shapefiles here:
> > >>> http://www.usna.edu/Users/oceano/pguth/srtm/rivers.zip
> > >>> Here is my code:
> > >>> library(rgdal)shape=readOGR("af_riv_15s.shp", layer="af_riv_15s")
> > >>>
> > >>> Thank you for your help,Phil
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>         [[alternative HTML version deleted]]
> > >>>
> > >>> _______________________________________________
> > >>> R-sig-Geo mailing list
> > >>> R-sig-Geo@r-project.org
> > >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> > >>
> > >>
> > >>
> > >> --
> > >> Michael Sumner
> > >> Hobart, Australia
> > >> e-mail: mdsumner@gmail.com
> > >
> > >     [[alternative HTML version deleted]]
> > >
> > > _______________________________________________
> > > R-sig-Geo mailing list
> > > R-sig-Geo@r-project.org
> > > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> > >
> >
> > --
> > Roger Bivand
> > Department of Economics, NHH Norwegian School of Economics,
> > Helleveien 30, N-5045 Bergen, Norway.
> > voice: +47 55 95 93 55; fax +47 55 95 95 43
> > e-mail: Roger.Bivand@nhh.no
> >
>
>         [[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>



-- 
http://www.keittlab.org/

	[[alternative HTML version deleted]]

