network-functions connect_ne


  • connect_ne(arc_polygon_dataitem, arc_polygon_match_dataitem, point_dataitem, point_match_dataitem)


The connect_ne functions works in a similar way as the second variant of the connect function, with the extra condition that the values of the arc_polygon_match_dataitem may not match with the values of the point_match_dataitem.

The figure shows an example of how this connect_ne function can be used.

With the connect function the blue star location would be connected to the orange road. Assume this orange road is a highway, then a connection should not be made to this road. The connect_ne can be used to connect the blue star to the nearest road not being a highway.


The value-type of matching arguments: arc_polygon_match_dataitem and point_match_dataitem need to be uint32. This means street names (as in the example) first need to be converted to street index-numbers, see the example.

Points with null values for the point_match_dataitem will always be connected to the nearest road (even if the road has a null value in the arc_polygon_match_dataitem).

To arcs/polygons with null values for the arc_polygon_match_dataitem, no points will be connected (except for points that are nearest to these roads and have a null value as point_match_dataitem).

applies to

  • data-item arc_polygon_dataitem with composition type arc or polygon. Be aware, if you connect points to polygons, always use a split_polygon first of the polygon geometry to get rid of the connection lines in polygons between islands and lakes.
  • data item point_dataitem with fpoint or dpoint value-type
  • data items arc_polygon_match_dataitem and point_match_dataitem with uint32 value type.


  1. The value type of the arc_polygon_dataitem and point_dataitem arguments must match.
  2. The arc_polygon_dataitem and arc_polygon_match_dataitem arguments need to have the same domain-unit.
  3. The point_dataitem and point_match_dataitem arguments need to have the same domain unit.

since version



unit<uint32> location : nrofrows = 5
   attribute<point_rd> point      := src/location/point;
   attribute<string>   streetname : ['Astreet','CRoad','BStreet','DSquare','BStreet'];
   attribute<street>   street_rel := rlookup(streetname, street/values);
unit<uint32> road : nrofrows = 4
   attribute<point_rd> line (arc) := src/road/line;
   attribute<string>   streetname : ['Astreet','BStreet','CRoad','DSquare'];
   attribute<street>   street_rel := rlookup(streetname, street/values);
unit<uint32> street := unique(roadarcs/street);

unit<uint32> connect_ne := connect_ne(road/line, road/street_rel, location/point, location/street_rel);

see also