IFC 4.3.x development

8.17.3.1 IfcPhysicalComplexQuantity

Change log

IFC4

additionswhere_rulesNoSelfReference
additionswhere_rulesUniqueQuantityNames
deletionswhere_rulesWR21

8.17.3.1.1 Semantic definitions at the entity

The complex physical quantity, IfcPhysicalComplexQuantity, is an entity that holds a set of single quantity measure value (as defined at the subtypes of IfcPhysicalSimpleQuantity), that all apply to a given component or aspect of the element.

EXAMPLE: A layered element, like a wall, may have several material layers, each having individual quantities, like footprint area, side area and volume. An instance of IfcPhysicalComplexQuantity would group these individual quantities (given by a subtype of IfcPhysicalSimpleQuantity) and name them according to the material layer name by using the Name attribute. The Discrimination attribute would then be 'layer'.

A section "Quantity Use Definition" at individual entities as subtypes of IfcBuildingElement gives guidance to the usage of the Name and Discrimination attribute to characterize the complex quantities.

HISTORY  New entity in IFC2x2 Addendum 1.

IFC2x2 ADDENDUM 1 CHANGE  The entity IfcPhysicalComplexQuantity has been added. Upward compatibility for file based exchange is guaranteed.

8.17.3.1.1 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.
IfcPhysicalComplexQuantity
3 HasQuantities SET [1:?] OF IfcPhysicalQuantity Set of physical quantities that are grouped by this complex physical quantity according to a given discrimination.
4 Discrimination IfcLabel Identification of the discrimination by which this physical complex property is distinguished. Examples of discriminations are 'layer', 'steel bar diameter', etc.
5 Quality OPTIONAL IfcLabel Additional indication of a quality of the quantities that are grouped under this physical complex quantity.
6 Usage OPTIONAL IfcLabel Additional indication of a usage type of the quantities that are grouped under this physical complex quantity.

8.17.3.1.2 Entity inheritance

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

8.17.3.1.3 Formal representations

ENTITY IfcPhysicalComplexQuantity
 SUBTYPE OF (IfcPhysicalQuantity);
	HasQuantities : SET [1:?] OF IfcPhysicalQuantity;
	Discrimination : IfcLabel;
	Quality : OPTIONAL IfcLabel;
	Usage : OPTIONAL IfcLabel;
 WHERE
	NoSelfReference : SIZEOF(QUERY(temp <* HasQuantities | SELF :=: temp)) = 0;
	UniqueQuantityNames : IfcUniqueQuantityNames(HasQuantities);
END_ENTITY;