IfcQuantityLength

Definition from IAI: A physical quantity, IfcQuantityLength, 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 IFC Release 2.x . It replaces the calcXxx attributes used in previous IFC Releases.

EXPRESS specification:

ENTITY IfcQuantityLength

SUBTYPE OF (

IfcPhysicalSimpleQuantity);

LengthValue

IfcLengthMeasure;

WHERE

WR21	:	NOT(EXISTS(SELF\IfcPhysicalSimpleQuantity.Unit)) OR (SELF\IfcPhysicalSimpleQuantity.Unit.UnitType = IfcUnitEnum.LENGTHUNIT);
WR22	:	LengthValue >= 0.;

END_ENTITY;

Attribute definitions:

LengthValue

Length measure value of this quantity.

Formal Propositions:

WR21	:	If a unit is given, the unit type shall be a lenght unit.
WR22	:	A valid length quantity shall be greater than or equal to zero.

Inheritance graph

ENTITY IfcQuantityLength;

ENTITY IfcPhysicalQuantity;

Name

IfcLabel;

Description

OPTIONAL IfcText;

INVERSE

PartOfComplex

SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities;

ENTITY IfcPhysicalSimpleQuantity;

Unit

OPTIONAL IfcNamedUnit;

ENTITY IfcQuantityLength;

LengthValue

IfcLengthMeasure;

END_ENTITY;