8.17.3.1 IfcPhysicalComplexQuantity
8.17.3.1.1 Semantic 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.
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 IfcBuiltElement gives guidance to the usage of the Name and Discrimination attribute to characterize the complex quantities.
New entity in IFC2x2 Addendum 1. 1 CHANGE The entity IfcPhysicalComplexQuantity has been added. Upward compatibility for file based exchange is guaranteed.8.17.3.1.2 Entity inheritance
8.17.3.1.3 Attributes
| # | Attribute | Type | Description |
|---|---|---|---|
| IfcPhysicalQuantity (4) | |||
| 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. |
| HasExternalReferences | SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects |
Reference to an external reference, e.g. library, classification, or document information, that is associated to the quantity. New inverse attribute. |
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| PartOfComplex | SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities |
Reference to a physical complex quantity in which the physical quantity may be contained. |
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| Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
| IfcPhysicalComplexQuantity (4) | |||
| 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. |
8.17.3.1.4 Formal propositions
| Name | Description |
|---|---|
| NoSelfReference |
The IfcPhysicalComplexQuantity should not reference itself within the list of HasQuantities. |
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| UniqueQuantityNames |
Every individual IfcPhysicalQuantity within the set HasQuantities shall have a unique Name attribute value. New rule in IFC4 |
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8.17.3.1.5 Formal representation
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;