The SEDRIS Data Representation Model
APPENDIX A - Classes
Classification Related Features

Class Name: Classification Related Features

Superclass - <Aggregate Feature>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies an aggregation of <Feature Hierarchy> instances organized according to their ECCs such that each <Feature Hierarchy> component represents:

  1. a different thematic layer, or
  2. a different classification of <Feature Representation> instances within a single thematic layer.

Each branch of a <Classification Related Features> instance therefore has a <Classification Data> instance associated with it as a link object, specifying its (possibly elaborated) classification.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

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

Example

  1. Several thematic layers of features might be grouped using a <Classification Related Features> instance, with each of its components representing a separate thematic layer (such as culture or vegetation). In such a case, the unique_descendants and strict_organizing_principle flags of the <Classification Related Features> instance should be set to SE_TRUE. The <Classification Data> link object associated with each of its components identifies the contents of each thematic layer, and each of the components is an independent topological complex and has a <Feature Topology Hierarchy> component.

    A region consisting of forest and water is represented as a <Classification Related Features> instance with strict_organizing_principle set to SE_TRUE, containing two <Union Of Features> components. The first <Union Of Features> component, containing the forest features, is specified through a <Classification Data> link object with tag = ECC_FOREST, while the second <Union Of Features> component, containing the water features, is specified through a <Classification Data> link object with tag = ECC_WATER.

  2. Considering the first example, suppose that roads run through the forest. The forest <Union Of Features> instance can then be replaced with another <Classification Related Features> instance having two branches, one representing environmental objects classified as ECC_ROAD and the other environmental objects classified as ECC_FOREST, and the strict_organizing_principle flag in the <Classification Related Features> instance from the previous example is set to SE_FALSE, because the forest branch at the coarse level contains non-forest (in this case, road) features.

  3. A large collection of features might be organized using a <Classification Related Features> instance with multiple <Union Of Features> components, containing cultural, vegetation, and surface drainage features, respectively.

FAQs

What is the purpose of this class?

The <Classification Related Features> class exists to provide a mechanism for hierarchically organizing <Feature Representation> instances according to their (possibly elaborated) classification.

Constraints

Associated to (one-way) (inherited)

Associated by (one-way) (inherited)

Composed of (two-way) (inherited)

Composed of (two-way)

Composed of (two-way metadata) (inherited)

Component of (two-way) (inherited)

Inherited Field Elements

SE_Boolean unique_descendants; 9
SE_Boolean strict_organizing_principle; 10

Notes

Associated to Notes


Feature_Representation

An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Hierarchy

An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Property_Grid

An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> link object on the association relationship. Each associated <Property Grid> instance indicates whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.

Associated from Notes


Feature_Representation

An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Geometry_Hierarchy

An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.


Property_Grid

An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> link object on the association relationship. Each associated <Property Grid> instance indicates whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.

Composed of Notes


Image_Mapping_Function

The <Image Mapping Function> components support texture mapping information for geometry that is to be derived from the <Aggregate Feature> instance by the consumer. These <Image Mapping Function> instances shall use <Image Anchor> components to specify the mapping.


Presentation_Domain

A <Presentation Domain> component is needed for <Aggregate Feature> instances that are significant only for a particular domain, such as radar.

Fields Notes

unique_descendants

If the value of the unique_descendants field is SE_TRUE, each descendant shall be unique in the sense that it shall appear in only one branch of this aggregation. Each descendant is a <Feature Representation> instance within the component tree rooted at the <Aggregate Feature> instance. If unique_descendants is SE_FALSE, at least one <Feature Representation> instance appears in more than one branch of the aggregation.

strict_organizing_principle

If the value of the strict_organizing_principle field is SE_TRUE, each branch of this aggregation strictly complies with the organizing principle for its particular subclass. If this value is SE_FALSE, at least one branch does not strictly comply with the given organizing principle. See the organizing principle constraint for each specific subclass for details.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS