IfcPhysicalComplexQuantity

BACnet MVD

#### IfcPhysicalComplexQuantity

Natural language names

| Komplexe physikalische Größe
| Physical Complex Quantity
| Quantité physique complexe

##### Semantic definitions at the entity

Entity definition

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.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
3 | HasQuantities | IfcPhysicalQuantity | S[1:?] | Set of physical quantities that are grouped by this complex physical quantity according to a given discrimination. |  | X
4 | Discrimination | IfcLabel |  | Identification of the discrimination by which this physical complex property is distinguished. Examples of discriminations are 'layer', 'steel bar diameter', etc. |  | X
5 | Quality | IfcLabel | ? | Additional indication of a quality of the quantities that are grouped under this physical complex quantity. |  | X
6 | Usage | IfcLabel | ? | Additional indication of a usage type of the quantities that are grouped under this physical complex quantity. |  | X

Formal Propositions

Rule | Description
--- | ---
NoSelfReference | The IfcPhysicalComplexQuantity should not reference itself within the list of HasQuantities.

UniqueQuantityNames

Every individual IfcPhysicalQuantity within the set HasQuantities shall have a unique Name attribute value.

> HISTORY New rule in IFC4

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
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
IfcPhysicalComplexQuantity
3 | HasQuantities | IfcPhysicalQuantity | S[1:?] | Set of physical quantities that are grouped by this complex physical quantity according to a given discrimination. |  | X
4 | Discrimination | IfcLabel |  | Identification of the discrimination by which this physical complex property is distinguished. Examples of discriminations are 'layer', 'steel bar diameter', etc. |  | X
5 | Quality | IfcLabel | ? | Additional indication of a quality of the quantities that are grouped under this physical complex quantity. |  | X
6 | Usage | IfcLabel | ? | Additional indication of a usage type of the quantities that are grouped under this physical complex quantity. |  | X

##### Formal representations

XML Specification
`<xs:element name="IfcPhysicalComplexQuantity" type="ifc:IfcPhysicalComplexQuantity" substitutionGroup="ifc:IfcPhysicalQuantity" nillable="true"/>
<xs:complexType name="IfcPhysicalComplexQuantity">
<xs:complexContent>
<xs:extension base="ifc:IfcPhysicalQuantity">
<xs:sequence>
<xs:element name="HasQuantities">
<xs:complexType>
<xs:sequence>
<xs:element ref="ifc:IfcPhysicalQuantity" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute ref="ifc:itemType" fixed="ifc:IfcPhysicalQuantity"/>
<xs:attribute ref="ifc:cType" fixed="set"/>
<xs:attribute ref="ifc:arraySize" use="optional"/>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="Discrimination" type="ifc:IfcLabel" use="optional"/>
<xs:attribute name="Quality" type="ifc:IfcLabel" use="optional"/>
<xs:attribute name="Usage" type="ifc:IfcLabel" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`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;

EXPRESS-G diagram

`

References: IfcPhysicalQuantity

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