spdep (version 0.3-8)

read.gwt2nb: Read and write spatial neighbour files

Description

The "gwt" functions read and write GeoDa GWT files (the example file baltk4.GWT was downloaded from the site given in the reference), and the "dat" functions read and write Matlab sparse matrix files as used by James LeSage's Spatial Econometrics Toolbox (the example file wmat.dat was downloaded from the site given in the reference).

Usage

read.gwt2nb(file, region.id=NULL)
write.sn2gwt(sn, file, shpfile=NULL, ind=NULL)
read.dat2listw(file)
write.sn2dat(sn, file)

Arguments

file

name of file with weights data

region.id

region IDs

sn

a spatial.neighbour object

shpfile

Shapefile name taken from GWT file for this dataset

ind

region id indicator variable name

Value

• read.gwt2nb returns a neighbour "nb" object with the generalised weights stored as a list element called "dlist" of the "GeoDa" attribute.

Details

Now attempts to honour the region.id argument given when reading GWT files.

References

Luc Anselin (2003) GeoDa 0.9 User's Guide, pp. 80--81, Spatial Analysis Laboratory, Department of Agricultural and Consumer Economics, University of Illinois, Urbana-Champaign, http://agec221.agecon.uiuc.edu/csiss/pdf/geoda093.pdf; also http://spatial-econometrics.com/data/contents.html

See Also

read.gal

Examples

data(baltimore)
STATION <- baltimore$STATION
gwt1 <- read.gwt2nb(system.file("etc/weights/baltk4.GWT", package="spdep")[1],
 STATION)
cat(paste("Neighbours list symmetry;", is.symmetric.nb(gwt1, FALSE, TRUE),
 ""))
listw1 <- nb2listw(gwt1, style="B", glist=attr(gwt1, "GeoDa")$dist)
tmpGWT <- tempfile()
write.sn2gwt(listw2sn(listw1), tmpGWT)
gwt2 <- read.gwt2nb(tmpGWT, STATION)
cat(paste("Neighbours list symmetry;", is.symmetric.nb(gwt2, FALSE, TRUE),
 ""))
data(oldcol)
diffnb(gwt1, gwt2)
tmpMAT <- tempfile()
COL.W <- nb2listw(COL.nb)
write.sn2dat(listw2sn(COL.W), tmpMAT)
listwmat1 <- read.dat2listw(tmpMAT)
diffnb(listwmat1$neighbours, COL.nb, verbose=TRUE)
listwmat2 <- read.dat2listw(system.file("etc/weights/wmat.dat", 
 package="spdep")[1])
diffnb(listwmat1$neighbours, listwmat2$neighbours, verbose=TRUE)