IFC 4.3.x development

8.17.3.2 IfcPhysicalQuantity

Change log

IFC4

modificationsinverses PartOfComplex definitionChanged from SET OF [0:1] IfcPhysicalComplexQuantity FOR HasQuantities to SET OF [0:?] IfcExternalReferenceRelationship FOR RelatedResourceObjects
modificationsinverses PartOfComplex name Changed from PartOfComplex to HasExternalReferences

8.17.3.2.1 Semantic definitions at the entity

The physical quantity, IfcPhysicalQuantity, is an abstract entity that holds a complex or simple quantity measure together with a semantic definition of the usage for the single or several measure value.

The Name attribute defines the actual usage or kind of measure. The interpretation of the name label has to be established within the actual exchange context. In addition an informative text may be associated to each quantity by the Description attribute.

HISTORY  New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.

8.17.3.2.1 Attributes

# Attribute Type Description
IfcPhysicalQuantity
1 Name IfcLabel Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.
2 Description OPTIONAL IfcText Further explanation that might be given to the quantity.
HasExternalReferencesSET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjectsReference to an external reference, e.g. library, classification, or document information, that is associated to the quantity.

> IFC4 CHANGE New inverse attribute.
PartOfComplex SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities Reference to a physical complex quantity in which the physical quantity may be contained.

8.17.3.2.2 Entity inheritance

dot_inheritance IfcPhysicalComplexQuantity IfcPhysicalComplexQuantity IfcPhysicalQuantity IfcPhysicalQuantity IfcPhysicalComplexQuantity->IfcPhysicalQuantity IfcPhysicalSimpleQuantity IfcPhysicalSimpleQuantity IfcPhysicalSimpleQuantity->IfcPhysicalQuantity

8.17.3.2.3 Formal representations

ENTITY IfcPhysicalQuantity
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcPhysicalComplexQuantity
	,IfcPhysicalSimpleQuantity));
	Name : IfcLabel;
	Description : OPTIONAL IfcText;
 INVERSE
	HasExternalReferences : SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects;
	PartOfComplex : SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities;
END_ENTITY;