The composition type indicates how a sequence of coordinates need to be interpreted.
The GeoDMS supports two composition types:
- arc: an arc consists of at least a start and end point and 0 or more intermediates per entry.
- poly or polygon: a polygon consist of at least three points per entry, the last and first point need to be the same to create a closed polygon. The composition type poly is also used to indicate multiple elements in sequence-functions.
The composition type is configured for feature-attribute of arcs and polygons with the keyword arc or polygon in the same brackets as the domain-unit. A comma separates domain units and the composition type, the order is irrelevant.
For point feature attributes no composition type has to be configured.