IfcNamedUnit

Semantic definitions at the entity

Entity definition

Definition from ISO/CD 10303-41:1992: A named unit is a unit quantity associated with the word, or group of words, by which the unit is identified.

NOTE Corresponding STEP name: named_unit, please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

Attribute definitions

#	Attribute	Type	Cardinality	Description	A
1	Dimensions	IfcDimensionalExponents	[1:1]	The dimensional exponents of the SI base units by which the named unit is defined.	X
2	UnitType	IfcUnitEnum	[1:1]	The type of the unit.	X

Formal Propositions

Rule	Description
WR1	Correct dimensions of the unit are established through the function IfcCorrectDimensions.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	A
IfcNamedUnit
1	Dimensions	IfcDimensionalExponents	[1:1]	The dimensional exponents of the SI base units by which the named unit is defined.	X
2	UnitType	IfcUnitEnum	[1:1]	The type of the unit.	X

Formal representations

XSD Specification

 <xs:element name="IfcNamedUnit" type="ifc:IfcNamedUnit" abstract="true" substitutionGroup="ifc:Entity" nillable="true"/>

 <xs:complexType name="IfcNamedUnit" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:Entity">

    <xs:sequence>

     <xs:element name="Dimensions" type="ifc:IfcDimensionalExponents" nillable="true" minOccurs="0"/>

    </xs:sequence>

    <xs:attribute name="UnitType" type="ifc:IfcUnitEnum" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcNamedUnit

 ABSTRACT SUPERTYPE OF(ONEOF(IfcConversionBasedUnit, IfcSIUnit));

  Dimensions : IfcDimensionalExponents;

  UnitType : IfcUnitEnum;

 WHERE

  WR1 : IfcCorrectDimensions (SELF.UnitType, SELF.Dimensions);
END_ENTITY;

 EXPRESS-G diagram