 | Mengenangabe - Länge |
 | Quantity Length |
 | Quantité de longueur |
| Item | SPF | XML | Change | Description | IFC2x3 to IFC4 4.0.0.0 |
|---|---|---|---|---|
| IfcQuantityLength | ||||
| Formula | ADDED |
IfcQuantityLength is a physical quantity that defines a derived length measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.
EXAMPLE A rafter within a roof construction may be measured according to its length (taking a common cross section into account). The actual size of the length depends on the method of measurement used.
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| 4 | LengthValue | IfcLengthMeasure | Length measure value of this quantity. | X | |
| 5 | Formula | IfcLabel | ? |
A formula by which the quantity has been calculated. It can be assigned in addition to the actual value of the quantity. Formulas could be mathematic calculations (like width x height), database links, or a combination. The formula is for informational purposes only.
IFC4 CHANGE Attribute added to the end of the attribute list. | X |
| Rule | Description |
|---|---|
| WR21 | If a unit is given, the unit type shall be a length unit. |
| WR22 | A valid length quantity shall be greater than or equal to zero. |
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| IfcPhysicalQuantity | |||||
| 1 | Name | IfcLabel | Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements. | X | |
| 2 | Description | IfcText | ? | Further explanation that might be given to the quantity. | X |
| HasExternalReferences | IfcExternalReferenceRelationship @RelatedResourceObjects | S[0:?] | Reference to an external reference, e.g. library, classification, or document information, that is associated to the quantity.
IFC4 CHANGE New inverse attribute. | X | |
| PartOfComplex | IfcPhysicalComplexQuantity @HasQuantities | S[0:1] | Reference to a physical complex quantity in which the physical quantity may be contained. | X | |
| IfcPhysicalSimpleQuantity | |||||
| 3 | Unit | IfcNamedUnit | ? | Optional assignment of a unit. If no unit is given, then the global unit assignment, as established at the IfcProject, applies to the quantity measures. | X |
| IfcQuantityLength | |||||
| 4 | LengthValue | IfcLengthMeasure | Length measure value of this quantity. | X | |
| 5 | Formula | IfcLabel | ? |
A formula by which the quantity has been calculated. It can be assigned in addition to the actual value of the quantity. Formulas could be mathematic calculations (like width x height), database links, or a combination. The formula is for informational purposes only.
IFC4 CHANGE Attribute added to the end of the attribute list. | X |
<xs:element name="IfcQuantityLength" type="ifc:IfcQuantityLength" substitutionGroup="ifc:IfcPhysicalSimpleQuantity" nillable="true"/>
<xs:complexType name="IfcQuantityLength">
<xs:complexContent>
<xs:extension base="ifc:IfcPhysicalSimpleQuantity">
<xs:attribute name="LengthValue" type="ifc:IfcLengthMeasure" use="optional"/>
<xs:attribute name="Formula" type="ifc:IfcLabel" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcQuantityLength
SUBTYPE OF (IfcPhysicalSimpleQuantity);
LengthValue : IfcLengthMeasure;
Formula : OPTIONAL IfcLabel;
WHERE
WR21 : NOT(EXISTS(SELF\IfcPhysicalSimpleQuantity.Unit)) OR
(SELF\IfcPhysicalSimpleQuantity.Unit.UnitType = IfcUnitEnum.LENGTHUNIT);
WR22 : LengthValue >= 0.;
END_ENTITY;
EXPRESS-G diagram
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