The function includes the region itself in its own list of neighbours, and sets attribute "self.included" to TRUE.

include.self(nb)

Arguments

nb

input neighbours list of class nb

Value

The function returns an object of class nb with a list of integer vectors containing neighbour region number ids; attribute "self.included" is set to TRUE.

Author

Roger Bivand Roger.Bivand@nhh.no

See also

Examples

columbus <- st_read(system.file("shapes/columbus.shp", package="spData")[1], quiet=TRUE)
col.gal.nb <- read.gal(system.file("weights/columbus.gal", package="spData")[1])
coords <- coordinates(as(columbus, "Spatial"))
summary(col.gal.nb, coords)
#> Neighbour list object:
#> Number of regions: 49 
#> Number of nonzero links: 230 
#> Percentage nonzero weights: 9.579342 
#> Average number of links: 4.693878 
#> Link number distribution:
#> 
#>  2  3  4  5  6  7  8  9 10 
#>  7  7 13  4  9  6  1  1  1 
#> 7 least connected regions:
#> 1 6 31 39 42 46 47 with 2 links
#> 1 most connected region:
#> 20 with 10 links
#> Summary of link distances:
#>    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
#>  0.1276  0.3613  0.4566  0.4694  0.5536  0.8924 
#> 
#>   The decimal point is 1 digit(s) to the left of the |
#> 
#>   1 | 3344
#>   1 | 99
#>   2 | 000011333344
#>   2 | 556677779999
#>   3 | 000011222222223344444444
#>   3 | 556666777777888888889999999999
#>   4 | 00001111112233333333334444
#>   4 | 55666666666666777777777788888899
#>   5 | 0011112222222222222233334444
#>   5 | 556666667788
#>   6 | 000000112244
#>   6 | 5577889999
#>   7 | 11112244
#>   7 | 557777
#>   8 | 1144
#>   8 | 55999999
#> 
summary(include.self(col.gal.nb), coords)
#> Neighbour list object:
#> Number of regions: 49 
#> Number of nonzero links: 279 
#> Percentage nonzero weights: 11.62016 
#> Average number of links: 5.693878 
#> Link number distribution:
#> 
#>  3  4  5  6  7  8  9 10 11 
#>  7  7 13  4  9  6  1  1  1 
#> 7 least connected regions:
#> 1 6 31 39 42 46 47 with 3 links
#> 1 most connected region:
#> 20 with 11 links
#> Summary of link distances:
#>    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
#>  0.0000  0.2576  0.4073  0.3870  0.5232  0.8924 
#> 
#>   The decimal point is 1 digit(s) to the left of the |
#> 
#>   0 | 0000000000000000000000000000000000000000000000000
#>   0 | 
#>   1 | 3344
#>   1 | 99
#>   2 | 000011333344
#>   2 | 556677779999
#>   3 | 000011222222223344444444
#>   3 | 556666777777888888889999999999
#>   4 | 00001111112233333333334444
#>   4 | 55666666666666777777777788888899
#>   5 | 0011112222222222222233334444
#>   5 | 556666667788
#>   6 | 000000112244
#>   6 | 5577889999
#>   7 | 11112244
#>   7 | 557777
#>   8 | 1144
#>   8 | 55999999
#>