Spatial link distance measures

Given a list of spatial neighbour links (a neighbours list of object type nb), the function returns the Euclidean distances along the links in a list of the same form as the neighbours list. If longlat = TRUE, Great Circle distances are used.

nbdists(nb, coords, longlat = NULL)

Arguments

nb

an object of class nb

coords

matrix of point coordinates, an object inheriting from SpatialPoints or an "sf" or "sfc" object; if the "sf" or "sfc" object geometries are in geographical coordinates (sf::st_is_longlat(x) == TRUE and sf::sf_use_s2() == TRUE), s2 will be used to find distances https://github.com/r-spatial/s2/issues/125

longlat

TRUE if point coordinates are longitude-latitude decimal degrees, in which case distances are measured in kilometers; if coords is a SpatialPoints object, the value is taken from the object itself

Value

A list with class nbdist

Author

Roger Bivand Roger.Bivand@nhh.no

See also

summary.nb, nb2listw

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 <- st_coordinates(st_centroid(columbus))
#> Warning: st_centroid assumes attributes are constant over geometries
dlist <- nbdists(col.gal.nb, coords)
dlist <- lapply(dlist, function(x) 1/x)
stem(unlist(dlist))
#> 
#>   The decimal point is at the |
#> 
#>   1 | 1111112222223333334444444444
#>   1 | 555555556666667777777777888888888899999999999999999999
#>   2 | 00000000111111111111111122222222222222333333333333334444
#>   2 | 55555555556666666666666677777777888888999999
#>   3 | 0000111111222233334444
#>   3 | 77779999
#>   4 | 223344
#>   4 | 77
#>   5 | 001144
#>   5 | 
#>   6 | 
#>   6 | 99
#>   7 | 
#>   7 | 88
#>