RE : Adjacency matrix of higher order (from winbugs to R)
Thank you Roger, problem resolved. Julien ________________________________________ De : Roger Bivand [Roger.Bivand at nhh.no] Date d'envoi : 5 mars 2010 09:06 ? : Julien Beguin Cc : r-sig-geo at stat.math.ethz.ch Objet : Re: [R-sig-Geo] Adjacency matrix of higher order (from winbugs to R)
On Thu, 4 Mar 2010, Julien Beguin wrote:
Hi everyone, I am trying to find a way to calculate an adjacency matrix from a polygon shapefile to make a CAR model in winbugs, but I would like to vary the order of neihborhood. I checked previous messages on the list but did not find this specific topic. I used the the spdep package to create an adjacency matrix (in list format) of order 2 and it works pretty fine:
Did you look at ?nblag - is that what you need? Roger
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shape <- readShapePoly("path_to_my_shapefile", IDvar="Id")
shape_nb<-poly2nb(shape)
data<-list(
N = length(shape_nb),
num=sapply(shape_nb, length),
adj=unlist(shape_nb),
lst = attr(shape_nb, "region.id"),
adj2 = lst[unlist(shape_nb)],
sumNumNeigh=length(unlist(shape_nb)
)
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is everyone know how to calculate an adjacency matrix in R for polygon
shapefile but for higher orders of neihborhood (ex: 3,4,5, etc...)? I did
not see any option with the function poly2nb() in spdep package but I
imagine that other tools have to exist. Your help would be greatly
appreciated.
Best regards,
Julien
-- 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: Roger.Bivand at nhh.no