spatialRegroup - Iterative Spatial Regrouping of Administrative Units by
Attributive Affinity
Evaluates the statistical coherence of existing
administrative partitions (e.g. inter-municipal groupings,
districts) by identifying spatial units whose attributive
profile is more similar to a neighbouring group than to their
own. Border units are iteratively reassigned to the group they
are most affine with, based on Euclidean or Mahalanobis
distance computed on user-supplied numeric variables, with
optional per-variable weighting and standardisation. Spatial
contiguity is enforced throughout: isolated candidates are
reintegrated into their original group, disconnected fragments
are resolved, and empty groups are restored. Convergence is
monitored via an eta-squared cohesion criterion. The resulting
partition can be compared to the original administrative
delineation using multilevel models, providing a quantitative
measure of boundary inefficiency.
