IfcQuantitySet

5.1.3.13 IfcQuantitySet

	Ensemble de quantités
	frei definierbare Mengenliste

IfcQuantitySet is the the abstract supertype for all quantity sets attached to objects. The quantity set is a container class that holds the individual quantities within a quantity tree. These quantities are interpreted according to their name attribute and classified according to theie measure type.

The same IfcQuantitySet can be assignd to multiple object occurrences, it should then be assigned by a single instance of IfcRelDefinedByProperties to a set of related objects. Those quantity sets are referred to as shared shared sets. It can also be assigned to an object type.

An IfcPropertySetTemplate may define the underlying structure, i.e. the required name, the applicable object or object types to which the quantity set can be attached, and the individual quantities that maybe included.

HISTORY New entity in IFC4.

Relationship use definition

Quantity sets are related to other objects by using the relationship object that refers to the corresponding object:

Occurrence Object: IfcRelDefinesByProperties using the inverse attribute DefinesOccurrence.
Type Object: using a direct link by inverse attribute DefinesType.
Underlying template: IfcRelDefinesByTemplate using the inverse attribute IsDefinedBy.
External reference: subtypes of IfcRelAssociates are used to provide a link to a classification system, or external library providing further reference to the quantity set. Accessible by inverse attribute HasAssociations.

Attribute use definition

Instances of IfcQuantitySet are used to assign named sets of individual quantities (complex or single quantities). Each individual quantity has a significant name string. Some quantity sets are included in the IFC specification and have a predefined set of quantities indicated by assigning a significant name. These quantity sets are listed under "quantity sets" main menu item within this specification and in the object documentation sheet for those object to which they are applicable.

XSD Specification:

<xs:element name="IfcQuantitySet" type="ifc:IfcQuantitySet" abstract="true" substitutionGroup="ifc:IfcPropertySetDefinition" nillable="true"/>
<xs:complexType name="IfcQuantitySet" abstract="true">
  <xs:complexContent>
   <xs:extension base="ifc:IfcPropertySetDefinition"/>
  </xs:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcQuantitySet

ABSTRACT SUPERTYPE OF(IfcElementQuantity)

SUBTYPE OF (IfcPropertySetDefinition);

END_ENTITY;

Inheritance Graph:

ENTITY IfcQuantitySet

ENTITY IfcRoot

GlobalId	:	IfcGloballyUniqueId;
OwnerHistory	:	OPTIONAL IfcOwnerHistory;
Name	:	OPTIONAL IfcLabel;
Description	:	OPTIONAL IfcText;

ENTITY IfcPropertyDefinition

INVERSE

HasContext	:	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
HasAssociations	:	SET OF IfcRelAssociates FOR RelatedObjects;

ENTITY IfcPropertySetDefinition

INVERSE

DefinesType	:	SET OF IfcTypeObject FOR HasPropertySets;
DefinesOccurrence	:	SET [0:1] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition;

ENTITY IfcQuantitySet

END_ENTITY;

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