card: Cardinalities for neighbours lists
In spdep: Spatial Dependence: Weighting Schemes, Statistics and Models

Description Usage Arguments Details Value Author(s) References See Also Examples

The function tallies the numbers of neighbours of regions in the neighbours list.

card(nb)

`nb`	a neighbours list object of class `nb`

“nb” objects are stored as lists of integer vectors, where the vectors contain either the indices in the range 1:n for n as length(nb) of the neighbours of region i, or as.integer(0) to signal no neighbours. The function card(nb) is used to extract the numbers of neighbours from the “nb” object.

An integer vector of the numbers of neighbours of regions in the neighbours list.

Roger Bivand Roger.Bivand@nhh.no

Bivand R, Pebesma EJ, Gomez-Rubio V, (2008) Applied Spatial Data Analysis with R, Springer, New York, pp. 239-251; Bivand R, Portnov B, (2004) Exploring spatial data analysis techniques using R: the case of observations with no neighbours. In: Anselin L, Florax R, Rey S, (eds.), Advances in Spatial Econometrics, Methodology, Tools and Applications. Berlin: Springer-Verlag, pp. 121-142.

summary.nb

1 2	example(columbus) table(card(col.gal.nb))

Loading required package: sp
Loading required package: spData
To access larger datasets in this package, install the spDataLarge
package with: `install.packages('spDataLarge',
repos='https://nowosad.github.io/drat/', type='source')`
Loading required package: sf
Linking to GEOS 3.8.0, GDAL 3.0.4, PROJ 6.3.1

colmbs> columbus <- st_read(system.file("shapes/columbus.shp", package="spData")[1], quiet=TRUE)

colmbs> col.gal.nb <- read.gal(system.file("weights/columbus.gal", package="spData")[1])

 2  3  4  5  6  7  8  9 10 
 7  7 13  4  9  6  1  1  1