listw2sn: Spatial neighbour sparse representation
In spdep: Spatial Dependence: Weighting Schemes, Statistics and Models

Description Usage Arguments Value Author(s) See Also Examples

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. The as.spam.listw method converts a "listw" object to a sparse matrix as defined in the spam package, using listw2sn().

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listw2sn(listw)
sn2listw(sn)
as.spam.listw(listw)

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

listw2sn()returns 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

Roger Bivand Roger.Bivand@nhh.no

nb2listw

example(columbus)
col.listw <- nb2listw(col.gal.nb)
col.listw$neighbours[[1]]
col.listw$weights[[1]]
col.sn <- listw2sn(col.listw)
str(col.sn)
## Not run: 
col.sp <- as.spam.listw(col.listw)
str(col.sp)

## End(Not run)