Create Aggregation

Feature Description

Collection Object is a type of feature used to describe relationships between objects in nautical charts. It expresses interrelationships by referencing other feature objects without possessing its own spatial info. Therefore, collection objects only contain attributes. In SuperMap iDesktopX, collection objects are stored in attribute tables, where each collection object corresponds to a record, and its associations with referenced features are also stored through attribute tables.

Aggregation refers to an association or grouping relationship established between features. This relationship helps visually express logical and functional connections between different feature objects. According to S-57 electronic chart specifications, collection objects mainly include Aggregated Feature Objects and Associated Feature Objects. Aggregated features represent clustered relationships, while associated features describe connections between objects. Note that collection objects can only express peer relationships and cannot create "Parent-Child Feature Objects" (C_STAC).

The purpose of building collection objects is to organize and manage feature data more effectively, facilitating the expression of complex inter-feature relationships:

  • Aggregated Feature Object (C_AGGR): Combines multiple features into a higher-level feature. For example, grouping multiple traffic lanes and boundaries into a traffic zone, or combining multiple piers with the same name into an integrated pier.
  • Associated Feature Object (C_ASSO): Describes associative relationships between features. For example, marking the relationship between a buoy and a shipwreck.

Steps

Below are the detailed steps for creating aggregation with practical examples:

  1. Data preparation：
    • Open workspace Chart.swmu from SuperMap sample data folder SampleData\ApplicationMap\Chart. Convert the non-editable group GB4X0000_52000 in the Chart datasource to an editable group, obtaining GB4X0000 group.
    • Double-click to load the editable chart group GB4X0000 into the map. Set display type to Standard and Chart Symbology.
  2. Create aggregation：
    • Chart Tab -> Relationship Management group -> Click Aggregation button to open the Aggregation panel. The panel contains two sections: upper for collection objects and lower for reference objects.

       

    • Click Add combination relationship button's dropdown menu and select Related objects to create an association (C_ASSO) attribute table for storing associated object info.

    • Select Collection object mark from the dropdown menu to create an aggregation (C_AGGR) tabular dataset for storing collection object records.

  3. Add reference objects：
    • Add the selected objects from map: Select the newly created association (C_ASSO) table. Choose the harbor area (DOCARE) and gate (GATCON) objects at the lower-left of the chart to build associations. After selection, click Add Reference Objects from Map on the reference object toolbar. In the Add the selected objects from map dialog, add selected objects to the Select Result list. Click Apply to complete.

       

    • Add from dataset: Select the aggregation (C_AGGR) table. Click Add reference objects from dataset toolbar button. In the Add from dataset dialog, add all Traffic Separation Scheme Lane (TSSLPT) and Traffic Separation Scheme Boundary (TSSBND) objects to the select result list. Click Apply to complete.
  4. Result verification：
    • The aggregation panel displays two newly created relationships (harbor area-gate association; traffic lane-boundary aggregation), as shown:

       

    • In Workspace Manager, right-click and select Browse Attribute Table to view the Collection and Link attribute tables under this chart group.

Related Topics

Create Master-slave

Build Master-slave Relationships in Batches

Modify Relationships