IFC 4.3.x development

8.11.3.1 IfcContextDependentUnit

Change log

IFC4

additionsinversesHasExternalReference

8.11.3.1.1 Semantic definitions at the entity

NOTE  Definition according to ISO/CD 10303-41:1992
A context dependent unit is a unit which is not related to the SI system.

NOTE  The number of parts in an assembly is a physical quantity measured in units that may be called "parts" but which cannot be related to an SI unit.

NOTE  Corresponding ISO 10303 name: context_dependent_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY  New entity in IFC1.5.1.

8.11.3.1.1 Attributes

# Attribute Type Description
IfcNamedUnit
1 Dimensions IfcDimensionalExponents The dimensional exponents of the SI base units by which the named unit is defined.
2 UnitType IfcUnitEnum The type of the unit.
IfcContextDependentUnit
3 Name IfcLabel The word, or group of words, by which the context dependent unit is referred to.
HasExternalReferenceSET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjectsReference to external information, e.g. library, classification, or document information, which is associated with the context dependent unit.

> IFC4 CHANGE New inverse attribute

8.11.3.1.2 Entity inheritance

dot_inheritance IfcContextDependentUnit IfcContextDependentUnit IfcNamedUnit IfcNamedUnit IfcContextDependentUnit->IfcNamedUnit IfcConversionBasedUnit IfcConversionBasedUnit IfcConversionBasedUnit->IfcNamedUnit IfcSIUnit IfcSIUnit IfcSIUnit->IfcNamedUnit

8.11.3.1.3 Formal representations

ENTITY IfcContextDependentUnit
 SUBTYPE OF (IfcNamedUnit);
	Name : IfcLabel;
 INVERSE
	HasExternalReference : SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects;
END_ENTITY;