IfcPhysicalComplexQuantity

复杂物理量IfcPhysicalComplexQuantity是一个实体，它包含一组单个数量度量值（如IfcPhysicalSimpleQuantity的子类型所定义的），这些值都适用于元素的给定组件或方面。

示例：分层图元（如墙）可能有多个材质层，每个层都有单独的数量，如迹线面积、侧面积和体积。IfcPhysicalComplexQuantity的实例将对这些单独的量（由IfcPhysicalSimpleQuantity的子类型给定）进行分组，并使用“名称”属性根据材质图层名称对它们进行命名。然后，Discrimination属性将是“layer”。

作为IfcBuildingElement子类型的单个实体的“数量使用定义”一节为使用Name和Discrimination属性来描述复杂数量提供了指导。

IFC2x2附录1中增加的新实体。

如果已添加实体IfcPhysicalComplexQuantity，则更改实体IFC2x2附录1。保证了基于文件的交换的向上兼容性。

Formal Propositions

Rule	Description
NoSelfReference	IfcPhysicalComplexQuantity不应在HasQuantity列表中引用自身。
UniqueQuantityNames	集合hasQuantilities中的每个单独IfcPhysicalQuantity都应具有唯一的Name属性值。 IFC4历史新规则

 

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcPhysicalQuantity
1	Name	IfcLabel	[1:1]	Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.	X
2	Description	IfcText	[0:1]	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.	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	[1:1]	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	[0:1]	Additional indication of a quality of the quantities that are grouped under this physical complex quantity.	X
6	Usage	IfcLabel	[0:1]	Additional indication of a usage type of the quantities that are grouped under this physical complex quantity.	X

 

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;