how to get the values for corresponding neighbors
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