[R-sig-Geo] GIS Tasks in R

[Roger Bivand]

On Tue, 6 Feb 2007, Tim Keitt wrote:

> In addition to Rogers advise, you might take a peek at the functions
> available in postgis. Once you have polys in the postgis database, you
> can do quite a lot of geometry ops by eg "select intersection(poly1,
> poly2) from tabname" and so on. There's some grunt work involved. Its
> certainly not pointy-clicky (although QGIS and GRASS have some ability
> to work with postgis). I have found some useful functions there.
> Documentation is pretty good too.

And as Edzer tried out recently, you can get data to PostGIS from rgdal 
if your GDAL/OGR is built with PostGIS (PostgreSQL anyway) support - 
writeOGR(). We didn't try readOGR(), but it ought to work if the driver is 
present. Reports welcome.

Roger

> 
> THK
> 
> On 2/6/07, CJ Jackson <cwjacksonjr at hotmail.com> wrote:
> > Hi everyone,
> >
> > I'm currently working on my PhD (geology) and would like to explore the
> > possible GIS capabilities of R.  I currently use ESRI's ArcView (3.x),
> > ArcGIS (9.1), and ArcInfo (9) software for all of my GIS work.  I have
> > written an "extension" for the old ArcView that performs various
> > analyses of points/polylines/polygons and have been wanting to update
> > the extension for the latest version of ArcGIS to help me solve various
> > research problems.  With that being said, I discovered 'R' last year and
> > fell in love with it and have been using it for data analysis of
> > attribute tables from GIS Shapefiles.  Ultimately, as part of my
> > research, I would like to make a package for R that would handle various
> > GIS tasks of shapefiles themselves, not just their data tables.  It
> > would be great to have a analysis package for my research that is not
> > solely dependent on ESRI's software.  Furthermore, I dread programming
> > in Visual Basic for the new ArcGIS because I have limited programming
> > skills.  Here are some of the tasks I would like to perform:
> >
> > - produce a new point shapefile that contains points where two or more
> > shapefiles with polylines intersect
> > - intersect two or more shapefiles with polygons and store the results
> > in a new shapefile
> > - calculate area of polygons
> > - calculate the distance from a point shapefile to another point shapefile
> >
> > Is this possible in R, or, am I barking up the wrong tree?  Thanks!
> >
> > cj
> >
> > _______________________________________________
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> > R-sig-Geo at stat.math.ethz.ch
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
> 
> 
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no