Thanks David and Milton for replies. No, I don't have the coordiates. In other words, my data are not point data. But I think there is a way to test of spatial dependence for areal data or lattice data. In this case, the variable of interest is typically the average value of an area instead of a point. Do you how to do this?
Thank you. Xu On 12/6/06, Milton Cezar Ribeiro <[EMAIL PROTECTED]> wrote: > > I never used it, but I beleave that it is a job for "mantel.rtest()" > available on "ade4" package. > > In fact Farrar are right, you will neet the XY coordinates. Give a look at > "Legendre & Legendre" text book. > > HTH, > > Miltinho > Brazil > > David Farrar <[EMAIL PROTECTED]> escreveu: > > > In addition to the 25 numbers, I assume you have coordinates of each field. > Otherwise, I don't understand what you are trying to do. I think ecologists > like to use a test due to Mantel in this situation. > > The prefix "auto" means "self," of course, the idea being that measurements > of the same variable under different conditions are correlated. I guess this > would be a case of "autodependence." For correlation versus dependence, check > your intro stats book. > > de nada, > X'X > > Farrar > > > Xu Yuan wrote: > hello R-friends, > > I am a R beginner and try to ask a basic question: > > How to test the spatial dependence of a column of data? for example, I have > 25 agricultural fields, and I measure the average slope (%) or pH for each > field. All I have is 25 numbers. > > PS, could someone confirm that "spatial dependence" is equivalent to > "spatial correlation" or "spatial autocorrelation" or not. > > Thank you very much. > XY > > [[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. > > > [[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. > > > > ________________________________ O Yahoo! está de cara nova. Venha conferir! > > ______________________________________________ [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.
