listw2sn {spdep}R Documentation

Spatial neighbour sparse representation

Description

The function makes a "spatial neighbour" object representation (similar to the S-PLUS spatial statististics module representation of a "listw" spatial weights object. sn2listw() is the inverse function to listw2sn(), creating a "listw" object from a "spatial neighbour" object

Usage

listw2sn(listw)
sn2listw(sn)

Arguments

listw a listw object from for example nb2listw
sn a spatial.neighbour object

Value

A data frame with three columns, and with class spatial.neighbour:

from region number id for the start of the link (S-PLUS row.id)
to region number id for the end of the link (S-PLUS col.id)
weights weight for this link

logSpwdet returns log det(I - rho * W).

Author(s)

Roger Bivand Roger.Bivand@nhh.no

See Also

nb2listw, errorsarlm, lagsarlm

Examples

data(columbus)
col.listw <- nb2listw(col.gal.nb)
col.listw$neighbours[[1]]
col.listw$weights[[1]]
col.sn <- listw2sn(col.listw)
str(col.sn)
W <- asMatrixCsrListw(similar.listw(col.listw))
str(W)
rho <- seq(-0.8, 0.9, 0.1)
for (i in rho) print(paste("rho:", i, "log(det(I - rho*W))",
  log(det(asMatrixCsrIrW(W, i)))), quote=TRUE)

[Package spdep version 0.3-12 Index]