This matrix represents the contiguities of 3111 US counties using the Queen criterion of at least a single shared boundary point. The representation is as a row standardised spatial weights matrix transformed to a symmetric matrix (see Ord (1975), p. 125).
data(USCounties)A \(3111 ^2\) symmetric sparse matrix of class
dsCMatrix with 9101 non-zero entries.
The data were read into R using read.gal, and
row-standardised and transformed to symmetry using
nb2listw and similar.listw.
This spatial weights object was converted to class
dsCMatrix using
as_dsTMatrix_listw and coercion.
Ord, J. K. (1975) Estimation methods for models of spatial interaction; Journal of the American Statistical Association 70, 120--126.