IFC 4.3.0.1 (IFC4X3) development

8.16.3.13 IfcPropertyTableValue

8.16.3.13.1 Semantic 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.

The units are handled by the DefiningUnit and DefinedUnit attributes, see Table 8.16.3.13.A 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) DefiningUnit 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 8.16.3.13.A — Table value property with values, measure types and units

Informal Propositions:

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

8.16.3.13.2 Entity inheritance

8.16.3.13.3 Attributes

# Attribute Type Description
IfcPropertyAbstraction (1)
HasExternalReferences SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects

Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.

IfcProperty (8)
1 Name IfcIdentifier

Name for this property. This label is the significant name string that defines the semantic meaning for the property.

2 Specification OPTIONAL IfcText

URI reference to a location with semantic definition or informative text to explain the property.

PartOfPset SET [0:?] OF IfcPropertySet FOR HasProperties

Reference to the IfcPropertySet by which the IfcProperty is referenced.

PropertyForDependance SET [0:?] OF IfcPropertyDependencyRelationship FOR DependingProperty

The property on whose value that of another property depends.

PropertyDependsOn SET [0:?] OF IfcPropertyDependencyRelationship FOR DependantProperty

The relating property on which the value of the property depends.

PartOfComplex SET [0:?] OF IfcComplexProperty FOR HasProperties

Reference to the IfcComplexProperty in which the IfcProperty is contained.

HasConstraints SET [0:?] OF IfcResourceConstraintRelationship FOR RelatedResourceObjects

User-defined constraints for the property.

HasApprovals SET [0:?] OF IfcResourceApprovalRelationship FOR RelatedResourceObjects

User-defined approvals for the property.

Click to show 9 hidden inherited attributes Click to hide 9 inherited attributes
IfcPropertyTableValue (6)
3 DefiningValues OPTIONAL LIST [1:?] OF UNIQUE IfcValue

List of defining values, which determine the defined values. This list shall have unique values only.

4 DefinedValues OPTIONAL LIST [1:?] OF IfcValue

Defined values which are applicable for the scope as defined by the defining values.

5 Expression OPTIONAL IfcText

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.

6 DefiningUnit OPTIONAL IfcUnit

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.

7 DefinedUnit OPTIONAL IfcUnit

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.

8 CurveInterpolation OPTIONAL IfcCurveInterpolationEnum

Interpolation of the curve between two defining and defined values that are provided. if not provided a linear interpolation is assumed.

Table 8.16.3.13.B

8.16.3.13.4 Formal propositions

Name 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.

(NOT(EXISTS(DefiningValues)) AND NOT(EXISTS(DefinedValues)))
OR (SIZEOF(DefiningValues) = SIZEOF(DefinedValues))
WR22

If DefiningValues are provided, then all values within the list of DefiningValues shall have the same measure type.

NOT(EXISTS(DefiningValues)) OR 
(SIZEOF(QUERY(temp <* SELF.DefiningValues | TYPEOF(temp) <> TYPEOF(SELF.DefiningValues[1])
)) = 0)
WR23

If DefinedValues are provided, then all values within the list of DefinedValues shall have the same measure type.

NOT(EXISTS(DefinedValues)) OR 
(SIZEOF(QUERY(temp <* SELF.DefinedValues | TYPEOF(temp) <> TYPEOF(SELF.DefinedValues[1])
)) = 0)
Table 8.16.3.13.C

8.16.3.13.5 Formal representation

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;

8.16.3.13.6 References

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8.16.3.13.7 Changelog

  • attribute, CurveInterpolation
  • where rule, WR21
  • where rule, WR22
  • where rule, WR23
  • where rule, WR1
  • where rule, WR2
  • where rule, WR3
  • attribute DefinedValues optional, Is now optional
  • attribute DefiningValues optional, Is now optional
  • attribute DefiningValues type, Changed from "list[1:?] of unique IfcValue" to "list[1:?] of IfcValue"
  • attribute DefiningValues type, Changed from "list[1:?] of IfcValue" to "list[1:?] of unique IfcValue"