On Wed, 6 Dec 2006, Xu Yuan wrote: > 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?
But do you know where the areas are in relation to each other? Does the spatialCovariance package help? Roger > > 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]] > > > > ______________________________________________ > > R-help@stat.math.ethz.ch 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]] > > > > ______________________________________________ > > R-help@stat.math.ethz.ch 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! > > > > > > ______________________________________________ > R-help@stat.math.ethz.ch 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] ______________________________________________ R-help@stat.math.ethz.ch 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.