[R-sig-Geo] how to get the values for corresponding neighbors

[Roger Bivand]

On Tue, 4 May 2010, rusers.sh wrote:

> Hi there,
>  Take the data of columbus(spdep) as an example. Say ?i? is one of the
> polygons, and ?j? represents its neighbours. How to get the vlues of
> ?sum(Wij*Xj)??  ?Wij? means the weights, which can be get by
> ?nb2listw$weights?.
> Say ?Xj? to be ?columbus$PLUMB?. The problem is how to get the right values
> of ?columbus$PLUMB? for the corresponding neighbours, so i can calculate the
> "sum(Wij*Xj)"? See the following example.
> example(columbus);coords <- coordinates(columbus)
> nbs <- dnearneigh(coords,0,4)
> nbslistw<-nb2listw(nbs, style="B")
> #nbslistw$neighbours; nbslistw$weights
> I can not figure it out. Anybody can give me some suggestions?

lag(nbslistw, x)

?lag.listw

HTH

Roger

> Thanks.
>
>

-- 
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