Mary, You might also want to look at the nncross function in the spatstat package.
-Don At 8:58 AM -0700 3/18/08, Rick Reeves wrote: >Mary: > >Have a look at this tutorial: > >http://nceas.ucsb.edu/scicomp/GISSeminar/UseCases/AssignClosestPointsR/AssignClosestPointsR.html > >Uses R, which has a good set of geospatial analysis functions. This >web site has several other examples! > >Hope this helps, >Rick Reeves > >[EMAIL PROTECTED] wrote: >>Hi all, >>I recently joined, and have a rather basic question. I'd appreciate any >>help to find some R routines to find the closest match to GIS >>coordinates. I suspect simply using the Euclidean distance. I could >>write some code but I suspect there is some already. I describe three >>classes of difficulties below. 1. Sometimes there are simple >>measurement error differences in GIS from >>vine coordinates measurement at different times. This may also relate to >>ability to get close to trunk in addition to equipment measurement >>error. >>2. Sometimes we encounter the problem of matching aerial spatial records >>with vines. Aerial and satellite imagery is on a different scales >>(pixels) to vine spacing. But we would like to be able to match these as >>best we can. >>3. Sometimes we want to match kriged clusters to target vine GPS >>coordinates. >> >>Typically I have 100 target vines at each of 5 vineyards. >> >>Euclidean distance approx. = square root of ( differences between >>Eastings squared plus the differences between Northings squared) >> >>Any help will be appreciated Mary Barnes >> >> [[alternative HTML version deleted]] >> >>_______________________________________________ >>R-sig-Geo mailing list >>R-sig-Geo@stat.math.ethz.ch >>https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> >> > > >Attachment converted: MacQMac:reeves.vcf (TEXT/R*ch) (01FDEEA0) >_______________________________________________ >R-sig-Geo mailing list >R-sig-Geo@stat.math.ethz.ch >https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- -------------------------------------- Don MacQueen Environmental Protection Department Lawrence Livermore National Laboratory Livermore, CA, USA 925-423-1062 _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
