The SEDRIS Data Representation Model
APPENDIX A - Classes
Union Of Feature Topology

Class Name: Union Of Feature Topology

Superclass - <Feature Topology Hierarchy>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is a collection of all of the <Feature Topology> instances that form a complete topological surface.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

  1. A thematic layer representing a transportation network might be broken up into four rectangular tiles. While the <Linear Feature> instances representing roads are allowed to extend across the tile boundaries, the <Feature Topology> instances that are located within each tile are organized into separate <Union Of Feature Topology> instances to support access by spatial location.

FAQs

What is the purpose of this class?

This class allows <Feature Topology> instances to be grouped in an arbitrary manner. It is used to ensure that all <Feature Topology> instances, particularly those that are not directly associated with any <Feature Representation>, have at least one aggregate.

Constraints

Composed of (two-way)

Component of (two-way) (inherited)

Component of (two-way)

Inherited Field Elements

SE_Feature_Topology_Level feature_topology_level; 1

Notes

Fields Notes

feature_topology_level

The feature_topology_level field specifies the level of feature topology that is present within the hierarchy represented by the <Feature Topology Hierarchy> instance.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS