I am trying to build a function to return the value(s) of a neighboring state(s) FIPS for any given state FIPS. So far I've been able to create a spatial weights matrix using the spdep::poly2nb() function, but this only returns an integer for the number of neighbors whereas I was hoping to get a vector/list. For example, f(08) for Florida would return c(09,01) for Mississippi and Alabama.
Is anyone familiar of a way to do this using queen contiguity?
> head(florida)
Simple feature collection with 6 features and 7 fields
geometry type: MULTIPOLYGON
dimension: XY
bbox: xmin: -82.77634 ymin: 28.30456 xmax: -80.73282 ymax: 29.42705
epsg (SRID): 4326
proj4string: +proj=longlat +datum=WGS84 +no_defs
STFIPS CTFIPS STATE COUNTY VERSION Shape_Leng Shape_Area geometry
1 12 12069 Florida Lake 05 3.580470 0.27591000 MULTIPOLYGON (((-81.6419 29...
2 12 12119 Florida Sumter 05 2.157470 0.13878814 MULTIPOLYGON (((-81.95419 2...
3 12 12117 Florida Seminole 05 1.542572 0.08248891 MULTIPOLYGON (((-80.98725 2...
4 12 12127 Florida Volusia 05 11.160615 0.27614808 MULTIPOLYGON (((-81.10706 2...
5 12 12095 Florida Orange 05 2.709400 0.23973772 MULTIPOLYGON (((-80.88002 2...
6 12 12017 Florida Citrus 05 11.969303 0.14907229 MULTIPOLYGON (((-82.6456 28...
> nb.FOQ = poly2nb(florida, queen = TRUE, row.names = florida$CTFIPS)
> nb.FOQ
Neighbour list object:
Number of regions: 67
Number of nonzero links: 312
Percentage nonzero weights: 6.950323
Average number of links: 4.656716
1 region with no links:
31