geos_polygon_connectivity - ObjectVision/GeoDMS GitHub Wiki
Geometric functions > geos_polygon_connectivity
- geos_polygon_connectivity(polygon_data_item)
geos_polygon_connectivity(polygon_data_item) finds all pairs of adjacent (touching or overlapping) polygons in the polygon_data_item and returns them as a new domain.
The result is a new domain unit (uint32) where each entry represents one adjacency relationship between two polygons. Two sub-attributes relate each entry back to the first and second polygon in the pair.
The geos_ prefix of the function name indicates that the implementation of the operator uses geos.
- attribute polygon_data_item with a polygon value type
- The composition type of the polygon_data_item needs to be polygon.
The result is a container (new domain unit of type uint32) with:
-
F1: relation to the domain of polygon_data_item for the first polygon in each adjacent pair -
F2: relation to the domain of polygon_data_item for the second polygon in each adjacent pair
14.0
unit<uint32> adjacency := geos_polygon_connectivity(district/geometry)
{
attribute<district> F1;
attribute<district> F2;
}