On Mon, 12 Mar 2007 [EMAIL PROTECTED] wrote: > I am trying to determine how to evaluate homogeneity of points in > three-dimensional space. > > In two-dimensional data, I have used functions available in the Spatial > package > and I've have looked into the spatstat package > but, as far as I can tell, neither appears to handle 3-dimensional > data. > > Is there another version, package, or software that does the same type > (G-function, etc.) of evaluation for 3-D data?
I believe that you are correct with regard to spatial, spatstat, and splancs. For G, it would be possible to get most of the way there using an off-CRAN package interfacing David Mount's Approximate Nearest Neighbours code that I can make available (depending on your platform), substantially improved thanks to Christian Sangiorgio. > set.seed(1) > library(ann) > D3 <- matrix(runif(3000), ncol=3) > res <- ann(D3)$dnn > quantile(res, seq(0,1,1/10)) > plot(ecdf(res)) The real difficulties would start with edge adjustment, sampling within a volume for simulation ought to be OK, at least for a cube. Roger > > Thanks sincerely, > Tom Filloon [Procter & Gamble, Cincinnati, Ohio USA] > > > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. > -- 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] ______________________________________________ [email protected] 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.
