IfcPropertyTableValue

Semantic definitions at the entity

Entity definition

IfcPropertyTableValue is a property with a value range defined by a property object which has two lists of (numeric or descriptive) values assigned. The values specify a table with two columns. The defining values provide the first column and establish the scope for the defined values (the second column). An optional Expression attribute may give the equation used for deriving the range value, which is for information purposes only.

The IfcPropertyTableValue defines a defining/defined property value combination for which the property name, the table with defining and defined values with measure type (and optional the units for defining and defined values) are given.

NOTE The IfcPropertyTableValue only captures properties that can be expressed by a table with two columns. Use IfcPropertyReferenceValue with the PropertyReference being an IfcTable to express all those properties that require a table with tree or more columns.

The units are handled by the DefiningUnit and DefinedUnit attributes, see Table 694 for an example of a table value property:

If the DefiningUnit or DefinedUnit attribute is not given, then the unit is already implied by the type of IfcMeasureValue or IfcDerivedMeasureValue. The associated unit can be found at the IfcUnitAssignment globally defined at the project level (IfcProject.UnitsInContext).
If the DefiningUnit or DefinedUnit attribute is given, then the unit assigned by the unit attribute overrides the globally assigned unit.

The IfcPropertyTableValue allows for the specification of a table of defining/defined value pairs of the property description. The optional attribute CurveInterpolation allows to determine the interval between two given values.

Name	DefiningValues	DefiningValue Type (through IfcValue)	DefinedValues	DefinedValue Type (through IfcValue)	DefingUnit	DefinedUnit
SoundTransmissionLoss	100	IfcFrequencyMeasure	20	IfcNumericMeasure	-	dB
	200	IfcFrequencyMeasure	42	IfcNumericMeasure
	400	IfcFrequencyMeasure	46	IfcNumericMeasure
	800	IfcFrequencyMeasure	56	IfcNumericMeasure
	1600	IfcFrequencyMeasure	60	IfcNumericMeasure
	3200	IfcFrequencyMeasure	65	IfcNumericMeasure

Table 694 — Table value property with values, measure types and units

HISTORY New entity in IFC2x.

IFC4 CHANGE Attributes DefiningValues and DefinedValues have been made OPTIONAL with upward compatibility for file based exchange. The attribute CurveInterpolation has been added.

Informal Propositions:

The list of DefinedValues and the list of DefiningValues are corresponding lists.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
3	DefiningValues	IfcValue	~L[1:?]	List of defining values, which determine the defined values. This list shall have unique values only.	X
4	DefinedValues	IfcValue	L[1:?]	Defined values which are applicable for the scope as defined by the defining values.	X
5	Expression	IfcText	[0:1]	Expression for the derivation of defined values from the defining values, the expression is given for information only, i.e. no automatic processing can be expected from the expression.	X
6	DefiningUnit	IfcUnit	[0:1]	Unit for the defining values, if not given, the default value for the measure type (given by the TYPE of the defining values) is used as defined by the global unit assignment at IfcProject.	X
7	DefinedUnit	IfcUnit	[0:1]	Unit for the defined values, if not given, the default value for the measure type (given by the TYPE of the defined values) is used as defined by the global unit assignment at IfcProject.	X
8	CurveInterpolation	IfcCurveInterpolationEnum	[0:1]	Interpolation of the curve between two defining and defined values that are provided. if not provided a linear interpolation is assumed.	X

Formal Propositions

Rule	Description
WR21	Either both DefiningValues and DefinedValues are not provided, or the number of members in the list of DefiningValues shall be the same as the number of members in the list of DefinedValues.
WR22	If DefiningValues are provided, then all values within the list of DefiningValues shall have the same measure type.
WR23	If DefinedValues are provided, then all values within the list of DefinedValues shall have the same measure type.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcPropertyAbstraction
	HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.	X
IfcProperty
1	Name	IfcIdentifier	[1:1]	Name for this property. This label is the significant name string that defines the semantic meaning for the property.	X
2	Description	IfcText	[0:1]	Informative text to explain the property.	X
	PartOfPset	IfcPropertySet @HasProperties	S[0:?]	Reference to the IfcPropertySet by which the IfcProperty is referenced.	X
	PropertyForDependance	IfcPropertyDependencyRelationship @DependingProperty	S[0:?]	The property on whose value that of another property depends.	X
	PropertyDependsOn	IfcPropertyDependencyRelationship @DependantProperty	S[0:?]	The relating property on which the value of the property depends.	X
	PartOfComplex	IfcComplexProperty @HasProperties	S[0:?]	Reference to the IfcComplexProperty in which the IfcProperty is contained.	X
	HasConstraints	IfcResourceConstraintRelationship @RelatedResourceObjects	S[0:?]	User-defined constraints for the property.	X
	HasApprovals	IfcResourceApprovalRelationship @RelatedResourceObjects	S[0:?]	User-defined approvals for the property.	X
IfcSimpleProperty
IfcPropertyTableValue
3	DefiningValues	IfcValue	~L[1:?]	List of defining values, which determine the defined values. This list shall have unique values only.	X
4	DefinedValues	IfcValue	L[1:?]	Defined values which are applicable for the scope as defined by the defining values.	X
5	Expression	IfcText	[0:1]	Expression for the derivation of defined values from the defining values, the expression is given for information only, i.e. no automatic processing can be expected from the expression.	X
6	DefiningUnit	IfcUnit	[0:1]	Unit for the defining values, if not given, the default value for the measure type (given by the TYPE of the defining values) is used as defined by the global unit assignment at IfcProject.	X
7	DefinedUnit	IfcUnit	[0:1]	Unit for the defined values, if not given, the default value for the measure type (given by the TYPE of the defined values) is used as defined by the global unit assignment at IfcProject.	X
8	CurveInterpolation	IfcCurveInterpolationEnum	[0:1]	Interpolation of the curve between two defining and defined values that are provided. if not provided a linear interpolation is assumed.	X

Formal representations

XSD Specification

 <xs:element name="IfcPropertyTableValue" type="ifc:IfcPropertyTableValue" substitutionGroup="ifc:IfcSimpleProperty" nillable="true"/>

 <xs:complexType name="IfcPropertyTableValue">

  <xs:complexContent>

   <xs:extension base="ifc:IfcSimpleProperty">

    <xs:sequence>

     <xs:element name="DefiningValues" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:group ref="ifc:IfcValue" maxOccurs="unbounded"/>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcValue"/>

       <xs:attribute ref="ifc:cType" fixed="list-unique"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="DefinedValues" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:group ref="ifc:IfcValue" maxOccurs="unbounded"/>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcValue"/>

       <xs:attribute ref="ifc:cType" fixed="list"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="DefiningUnit" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:group ref="ifc:IfcUnit"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="DefinedUnit" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:group ref="ifc:IfcUnit"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

    <xs:attribute name="Expression" type="ifc:IfcText" use="optional"/>

    <xs:attribute name="CurveInterpolation" type="ifc:IfcCurveInterpolationEnum" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcPropertyTableValue

 SUBTYPE OF (IfcSimpleProperty);

  DefiningValues : OPTIONAL LIST [1:?] OF UNIQUE IfcValue;

  DefinedValues : OPTIONAL LIST [1:?] OF IfcValue;

  Expression : OPTIONAL IfcText;

  DefiningUnit : OPTIONAL IfcUnit;

  DefinedUnit : OPTIONAL IfcUnit;

  CurveInterpolation : OPTIONAL IfcCurveInterpolationEnum;

 WHERE

  WR21 : (NOT(EXISTS(DefiningValues)) AND NOT(EXISTS(DefinedValues)))
OR (SIZEOF(DefiningValues) = SIZEOF(DefinedValues));
  WR22 : NOT(EXISTS(DefiningValues)) OR 
(SIZEOF(QUERY(temp <* SELF.DefiningValues | TYPEOF(temp) <> TYPEOF(SELF.DefiningValues[1])
)) = 0);
  WR23 : NOT(EXISTS(DefinedValues)) OR 
(SIZEOF(QUERY(temp <* SELF.DefinedValues | TYPEOF(temp) <> TYPEOF(SELF.DefinedValues[1])
)) = 0);
END_ENTITY;

 EXPRESS-G diagram

Item	Change	Description
IFC2x3 to IFC4
IfcPropertyTableValue
DefiningValues	MODIFIED	Instantiation changed to OPTIONAL.
DefinedValues	MODIFIED	Instantiation changed to OPTIONAL.
CurveInterpolation	ADDED
IFC4 Addendum 1
IfcPropertyTableValue
HasConstraints	ADDED
HasApprovals	ADDED

	Merkmal mit Tabellenwert
	Property Table Value
	Propriété à valeurs tabulaires