8.17.3.2 IfcPhysicalQuantity

RV ⓘ

AbV ⓘ

ABSTRACT This definition may not be instantiated

8.17.3.2.1 Semantic definition

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.

8.17.3.2.2 Entity inheritance

8.17.3.2.3 Attributes

#	Attribute	Type	Description
IfcPhysicalQuantity (4)
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.
	HasExternalReferences	SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects	Reference 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.

Table 8.17.3.2.A

8.17.3.2.4 Formal representation

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;