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IfcPhysicalComplexQuantity

Definition from buildingSMART: 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 IFC Release 2x2 Addendum 1.

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

EXPRESS specification:

ENTITY IfcPhysicalComplexQuantity
SUBTYPE OF ( IfcPhysicalQuantity);
HasQuantities  :  SET [1:?] OF IfcPhysicalQuantity;
Discrimination  :  IfcLabel;
Quality  :  OPTIONAL IfcLabel;
Usage  :  OPTIONAL IfcLabel;
WHERE
WR21  :  SIZEOF(QUERY(temp <* HasQuantities | SELF :=: temp)) = 0;
END_ENTITY;

Attribute definitions:

HasQuantities  :  Set of physical quantities that are grouped by this complex physical quantity according to a given discrimination.
Discrimination  :  Identification of the discrimination by which this physical complex property is distinguished. Examples of discriminations are 'layer', 'steel bar diameter', etc.
Quality  :  Additional indication of a quality of the quantities that are grouped under this physical complex quantity.
Usage  :  Additional indication of a usage type of the quantities that are grouped under this physical complex quantity.

Formal Propositions:

WR21  :  The IfcPhysicalComplexQuantity should not reference itself within the list of HasQuantities.

Inheritance graph

ENTITY IfcPhysicalComplexQuantity;
ENTITY IfcPhysicalQuantity;
Name  :  IfcLabel;
Description  :  OPTIONAL IfcText;
INVERSE
PartOfComplex  :  SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities;
ENTITY IfcPhysicalComplexQuantity;
HasQuantities  :  SET [1:?] OF IfcPhysicalQuantity;
Discrimination  :  IfcLabel;
Quality  :  OPTIONAL IfcLabel;
Usage  :  OPTIONAL IfcLabel;
END_ENTITY;