Unique ID

Functionality

The Unique ID operation can be used to assign unique identifiers to all elements in a segment, polygon or point map. The output map contains the same geographic information as the input map, but each point, segment or polygon will have a unique ID.

Furthermore, an attribute table is created for the output map. The table contains a column with the original classes, IDs or values of the input map; the areas of individual output polygons; the lengths of individual output segments.

Example:

In this example, the Unique ID operation is applied on segment map Water. The input map uses a class domain Water which contains three classes: River, Stream 1 and Stream 2. The output segment map and its attribute table have a Unique ID domain with IDs named Seg 1 to Seg 5.

Input segment map:

(Class domain water)

Output segment map:

(Unique ID domain)

Output table:

(Unique ID domain)

When no prefix is specified, the output IDs will be:

when an input polygon map is used: Pol 1, Pol 2, Pol 3, etc.
when an input segment map is used: Seg 1, Seg 2, Seg 3, etc.
when an input point map is used: Pnt 1, Pnt 2, Pnt 3, etc.

When a prefix is used, e.g. My Segments, then the output IDs will be My Segments 1, My Segments 2, etc.

Requirements for the input map:

No special requirements for the input point, segment or polygon map.

Domain of output map and attribute table:

The output map and its attribute table will use an internally defined UniqueID domain. The IDs have names as described above. The domain is stored by the output map (internal domain).

Attribute table for output map:

An attribute table will be automatically created for the output map. The table will obtain the same name as the output map. The table will contain the new IDs, and:

the names or values of the original input polygons, and the areas of individual output polygons;
the names or values of the original input segments, and the lengths of individual output segments;
the names or values of the original input points.

Coordinate system of output map:

The output map uses the same coordinate system and coordinate boundaries as the input map.

Tip:

For more information on internal domains and representations, refer to How to open internal domains/representations.