Interpolation within user-defined hydrogeologic regions

ps_split_domain() detects invalid geometry, overlaps, gaps, ambiguous boundary points, and unassigned points without repairing or inferring regions. ps_interpolate_regions() uses only observations assigned to each explicit polygon, preserves underpopulated failures, and does not smooth or average across boundaries. These independent interpolations do not implement groundwater-flow boundary conditions.

split <- ps_split_domain(domain, regions, "unit_id", points)
regional <- ps_interpolate_regions(points, regions, "unit_id", "TPS")