The SEDRIS Data Representation Model
APPENDIX A - Classes
Quadrant Related Features
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Class Name: Quadrant Related Features
Subclasses
This DRM class is concrete and has no subclasses.
Definition
An instance of this DRM class specifies an aggregation of
<Feature Hierarchy> objects in
which each component <Feature Hierarchy>
represents a branch of a Quadrant. The quadrant represented by a branch is
specified by the <Quadrant Data> associated
with that branch. The bounding region that the
<Feature Hierarchy> components occupy is
defined by the <Spatial Extent> of the
<Quadrant Related Features>.
Primary Page in DRM Diagram:
Secondary Pages in DRM Diagram:
This class appears on only one page of the DRM class diagram.
Example
Consider a region of terrain that is organized into quadrants, where the
upper-right quadrant consists of ocean, and the other three quadrants
consist of the terrain bordering the ocean. The ocean quadrant is not
represented in the producer's system. The region is represented in SEDRIS
by a <Quadrant Related Features>
with 3 component <Union Of Features>.
(Since the remaining quadrant had no
<Feature Representation> instances,
it was not represented.)
Consider a
<Quadrant Related Features> instance
linked to a <Union Of Features> instance
representing its upper-right quadrant, via a
<Quadrant Data> instance. The
<Quadrant Data> instance's
quadrant value is
SE_QUADRANT_RIGHT_FRONT.
FAQs
- If a <Quadrant Related
Features> has less than 4 components, why is the data being organized
under a <Quadrant Related Features>
at all?
A
<Quadrant Related Features> is
used when an object in the hierarchy contains spatial components that
occupy a certain quadrant. These quadrants might not contain
<Primitive Feature> objects, which is why
instances of this class can have less than four components.
- Where is the <Spatial Extent> component?
<Quadrant Related Features>
automatically has a <Spatial Extent> component,
because it is a <Feature Representation>.
Unlike <Feature Representations>
in general, however,
<Quadrant Related Features> has a
constraint stating that the <Spatial Extent>
component is mandatory.
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)
Notes
Associated to Notes
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> instance on the association
relationship.
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>
instance on the association relationship.
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> instance on the association relationship.
Each associated <Property Grid> instance will indicate whether the
entire <Property Grid> instance or only some specific cell data
within it is participating in the relationship in question.
Associated from Notes
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> instance on the association
relationship.
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>
instance on the association relationship.
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> instance on the association relationship.
Each associated <Property Grid> instance will indicate whether the
entire <Property Grid> instance or only some specific cell data
within it is participating in the relationship in question.
Composed of Notes
This relationship exists to support *attributes for derived objects.*
That is, these components are used only to specify texture mapping
information for geometry that is to be derived from the
<Aggregate Feature> by the consumer. These <Image Mapping Function>
instances shall use <Image Anchor> components to specify the mapping.
A <Presentation Domain> component is needed for instances of
<Aggregate Feature> that are significant only for a particular domain,
such as radar.
Fields Notes
If the value of the unique_descendants field is SE_TRUE, each
descendant, that is, each <Feature Representation> instance that
exists in the component tree rooted at the given <Aggregate Feature>,
shall be unique, in the
sense that it shall appear in only one branch of this aggregation.
If unique_descendants is SE_FALSE, at least one
<Feature Representation> instance
appears in more than one branch of the aggregation.
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.
Prev: Quadrant Data.
Next: Quadrant Related Geometry.
Up:Index.
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Last updated: July 16, 2004
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Copyright © 2004 SEDRIS™
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