point polygon operators - ObjectVision/GeoDMS GitHub Wiki

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Point-polygon operators relate point geometries to polygon geometries, and convert between points and vertex sequences. These are among the most commonly used operators in spatial analysis, enabling joins between point datasets and area datasets.

• point_in_polygon - for each point, return the index of the polygon that contains it (or null if none)
• point_in_ranked_polygon - for each point, return the index of the polygon that contains it according to a ranking attribute; used when polygons may overlap
• point_in_all_polygons - return all point-polygon containment pairs as a relation; used when a single point may lie in multiple polygons
• sequence2points - decompose each arc or polygon into its individual vertex points, one row per vertex
• points2sequence - construct arcs or polygons from an ordered sequence of vertices