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 length 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;