Fig. 4
From: A revised digital edition of Wurm & Hattori’s Language Atlas of the Pacific Area
This figure shows the effect of (i) aggregating polygons with matching metadata into MultiPolygon shapes and (ii) fixing invalid geometries. The shape on the left (from the shapefile) was drawn as single, self-intersecting ring and was turned into a proper polygon (on the right) by replacing it with its hull, removing the not explicitly marked hole. The highlighted polygon on the top right side was added to the shape due to identical metadata.
