bg_outer_multi_polygon - ObjectVision/GeoDMS GitHub Wiki

Geometric functions bg_outer_multi_polygon

• bg_outer_multi_polygon(polygon_data_item, size, nr_angles)

bg_outer_multi_polygon(polygon_data_item) results in a polygon data item with the outer ring of each polygon in the polygon_data_item. The resulting data item has the same domain unit as the polygon_data_item.

The bg_ prefix of the function name indicates that the implementation of operator uses boost geometry library.

A variant bg_outer_single_polygon with the same signature can be used to buffer single polygons.

The bg_outer_multi_polygon function can be used to get the outer boundary of a polygon. It removes all interior lakes, islands in these lakes etc.

• attribute polygon_data_item with a point value type and a composition type polygon.

14.11.2

attribute<fpoint> outer_polygon (polygon, district) := bg_outer_multi_polygon(polyset/geometry);