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 <[EMAIL PROTECTED]> 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 > > > > _______________________________________________ > > R-sig-Geo mailing list > > R-sig-Geo@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: [EMAIL PROTECTED] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo