Arc feature attributes are attributes with a two-dimensional value-type (PointGroup) and at least two coordinates for each entry in the domain-unit.

Arc attributes are used as feature attribute for vector data.

The points in the correct sequence define an arc, a line between a start point, zero or more intermediates and an end point. Arc attributes are often used for geographic coordinates of roads, railways, rivers etc.

To make the GeoDMS aware that a sequence of coordinates need to be interpreted as an arc, this is done by configuring the composition type to arc.


The following example shows the configuration of a domain-unit road, in which each road is represented by one arc. The data is read from an esri-shapefile with gdal.vect.

unit<uint32> road
:  StorageName = "%SourceDataDir%/OSM/road.shp"
,  StorageType = "gdal.vect"
   attribute<point_rd> geometry (arc);
   attribute<string>   name;

see also