Greetings I'm using R 2.8 with recent (last month) versions of the packages I need to use at present.
I'm interested in examining hierarchical spatio-temporal patterns in a data set. The data consist of 94 points (X, Y, UTM coordinates) at which catch rates for a fish were recorded and there are also estimates of prey available for these fish at the same locations. I have reason to believe that the relationships between predators and prey varies with spatial scale (nested processes). To test this hypothesis, I'd like to generate subsets of the points that are separated by distance ranges (1-50 km, 51-100 km, etc) so I can run Sncf (package ncf) on the subsets. I cannot find a way to do this with R code. Getting a distance matrix is easy. Using that to help generate a series of distance-based subsets is something I cannot figure out (without manually entering a list of all the point pairs). Any suggestions would be appreciated. For what it's worth, I did post this question to R-sig-geo as well. Dave Warner David Warner Research Fishery Biologist USGS Great Lakes Science Center 1451 Green Road Ann Arbor MI 48105 734.214.9392 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
