bg_union_polygon - ObjectVision/GeoDMS GitHub Wiki
Geometric functions bg_union_polygon
- bg_union_polygon(polygon_data_item)
- bg_union_polygon(polygon_data_item, relation)
bg_union_polygon(polygon_data_item, partitioning) results in an attribute with all polygons from polygon_data_item, grouped by the argument relation.
Lines between adjacent polygons within each group are removed.
The domain unit of the resulting attribute is the values unit of the relation.
In other GIS software, the term dissolve is often used for this operation.
- The composition type of the polygon_data_item item needs to be a polygon with an ipoint, spoint, fpoint, or dpoint value type.
- The domain unit of the polygon_data_item item must be of value type uint32.
- The domain unit of arguments polygon_data_item and relation must match.
- The order of points in the polygon_data_item needs to be clockwise for exterior bounds and counterclockwise for holes in polygons (right-hand rule).
- bg_union_polygon(D->*P) -> void->*P
- bg_union_polygon(D->*P, part_rel: D->R) -> R->*P
where P is a GeoDms point type with signed integer coordinates, i.e. 16, 32, or 64-bit signed integers, D is the domain of the argument, and R is the values unit of the partitioning part_rel.
15.6.0
parameter<fpoint> geometry (polygon) := bg_union_polygon(district/geometry);
attribute<fpoint> geometry (polygon, region) := bg_union_polygon(district/geometry, district/region_rel);