summary.nb.RdThe function prints summary measures for links in a neighbours list. If a
matrix of coordinates is given as well, summary descriptive measures for
the link lengths are also printed. Print and summary functions are also available for "listw" weights list objects, also reporting constants (S0, S1, S2) used in inference for global spatial autocorrelation statistics such as Moran's I, Geary's C, join-count tests and Getis-Ord G.
# S3 method for nb
summary(object, coords=NULL, longlat = NULL, scale = 1, ...)
# S3 method for nb
print(x, ...)
# S3 method for listw
summary(object, coords, longlat, zero.policy = attr(object, "zero.policy"),
scale = 1, adjust.n=TRUE, ...)
# S3 method for listw
print(x, zero.policy = attr(x, "zero.policy"), ...)an object of class nb
matrix of region point coordinates or a SpatialPoints object or an sfc points object
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
additional arguments affecting the output produced
an object of class nb
default attr(listw, "zero.policy") as set when listw was created, if attribute not set, use global option value; if FALSE stop with error for any empty neighbour sets
passed through to stem() for control of plot length
default TRUE, if FALSE the number of observations is not adjusted for no-neighbour observations, if TRUE, the number of observations in spweights.constants is adjusted
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_centroid(st_geometry(columbus), of_largest_polygon=TRUE)
col.gal.nb
#> Neighbour list object:
#> Number of regions: 49
#> Number of nonzero links: 230
#> Percentage nonzero weights: 9.579342
#> Average number of links: 4.693878
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
col.listw <- nb2listw(col.gal.nb, style="W")
col.listw
#> Characteristics of weights list object:
#> Neighbour list object:
#> Number of regions: 49
#> Number of nonzero links: 230
#> Percentage nonzero weights: 9.579342
#> Average number of links: 4.693878
#>
#> Weights style: W
#> Weights constants summary:
#> n nn S0 S1 S2
#> W 49 2401 49 23.48489 204.6687
summary(col.listw)
#> Characteristics of weights list object:
#> 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
#>
#> Weights style: W
#> Weights constants summary:
#> n nn S0 S1 S2
#> W 49 2401 49 23.48489 204.6687
col_geoms <- st_geometry(columbus)
col_geoms[21] <- st_buffer(col_geoms[21], dist=-0.05)
st_geometry(columbus) <- col_geoms
nb <- poly2nb(columbus)
summary(nb)
#> Neighbour list object:
#> Number of regions: 49
#> Number of nonzero links: 230
#> Percentage nonzero weights: 9.579342
#> Average number of links: 4.693878
#> 1 region with no links:
#> 21
#> 3 disjoint connected subgraphs
#> Link number distribution:
#>
#> 0 2 3 4 5 6 7 8 9 10
#> 1 5 9 12 4 10 2 4 1 1
#> 5 least connected regions:
#> 1 6 42 46 47 with 2 links
#> 1 most connected region:
#> 20 with 10 links
try(nb2listw(nb, style="W"))
#> Error in nb2listw(nb, style = "W") : Empty neighbour sets found
summary(nb2listw(nb, style="W", zero.policy=TRUE))
#> Characteristics of weights list object:
#> Neighbour list object:
#> Number of regions: 49
#> Number of nonzero links: 230
#> Percentage nonzero weights: 9.579342
#> Average number of links: 4.693878
#> 1 region with no links:
#> 21
#> 3 disjoint connected subgraphs
#> Link number distribution:
#>
#> 0 2 3 4 5 6 7 8 9 10
#> 1 5 9 12 4 10 2 4 1 1
#> 5 least connected regions:
#> 1 6 42 46 47 with 2 links
#> 1 most connected region:
#> 20 with 10 links
#>
#> Weights style: W
#> Weights constants summary:
#> n nn S0 S1 S2
#> W 48 2304 48 22.46811 199.4398
summary(nb2listw(nb, style="W", zero.policy=TRUE), adjust.n=FALSE)
#> Characteristics of weights list object:
#> Neighbour list object:
#> Number of regions: 49
#> Number of nonzero links: 230
#> Percentage nonzero weights: 9.579342
#> Average number of links: 4.693878
#> 1 region with no links:
#> 21
#> 3 disjoint connected subgraphs
#> Link number distribution:
#>
#> 0 2 3 4 5 6 7 8 9 10
#> 1 5 9 12 4 10 2 4 1 1
#> 5 least connected regions:
#> 1 6 42 46 47 with 2 links
#> 1 most connected region:
#> 20 with 10 links
#>
#> Weights style: W
#> Weights constants summary:
#> n nn S0 S1 S2
#> W 49 2401 48 22.46811 199.4398