Iterative Spatial Regrouping of Administrative Units by Attributive Affinity R package spatialRegroup version 0.1.0 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. Software Depends: R (>= 4.1.0) Imports: dplyr, sf, spdep, igraph, rlang Nicolas Ausello <nicolasausello@yahoo.fr> Comprehensive R Archive Network (CRAN) Nicolas Ausello [aut, cre] (ORCID: <https://orcid.org/0000-0003-3843-0463>) GPL-3 2026-05-11 application/tgz https://CRAN.R-project.org/package=spatialRegroup doi:10.32614/CRAN.package.spatialRegroup