IfcPhysicalQuantity

Semantic definitions at the entity

Entity 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.

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

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
1	Name	IfcLabel		Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.	X
2	Description	IfcText	?	Further explanation that might be given to the quantity.	X
	HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to an external reference, e.g. library, classification, or document information, that is associated to the quantity. IFC4 CHANGE New inverse attribute.	X
	PartOfComplex	IfcPhysicalComplexQuantity @HasQuantities	S[0:1]	Reference to a physical complex quantity in which the physical quantity may be contained.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcPhysicalQuantity
1	Name	IfcLabel		Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.	X
2	Description	IfcText	?	Further explanation that might be given to the quantity.	X
	HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to an external reference, e.g. library, classification, or document information, that is associated to the quantity. IFC4 CHANGE New inverse attribute.	X
	PartOfComplex	IfcPhysicalComplexQuantity @HasQuantities	S[0:1]	Reference to a physical complex quantity in which the physical quantity may be contained.	X

Formal representations

XML Specification

 <xs:element name="IfcPhysicalQuantity" type="ifc:IfcPhysicalQuantity" abstract="true" substitutionGroup="ifc:Entity" nillable="true"/>

 <xs:complexType name="IfcPhysicalQuantity" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:Entity">

    <xs:attribute name="Name" type="ifc:IfcLabel" use="optional"/>

    <xs:attribute name="Description" type="ifc:IfcText" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


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;

 EXPRESS-G diagram

	Physikalische Größe
	Physical Quantity
	Quantité physique