R: Cardinalities for neighbours lists

card {spdep} | R Documentation

## Cardinalities for neighbours lists

### Description

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

### Usage

    card(nb)

### Arguments

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

### Details

“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.

### Value

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

### Author(s)

Roger Bivand Roger.Bivand@nhh.no

### References

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.

### See Also

`summary.nb`

### Examples

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

[Package spdep version 1.2-2 Index]