ifcopenshell.api.unit.add_si_unit

Module Contents

ifcopenshell.api.unit.add_si_unit.add_si_unit(file: ifcopenshell.file, unit_type: str = 'LENGTHUNIT', prefix: str | None = None) → ifcopenshell.entity_instance

Add a new SI unit

The supported types are ABSORBEDDOSEUNIT, AMOUNTOFSUBSTANCEUNIT, AREAUNIT, DOSEEQUIVALENTUNIT, ELECTRICCAPACITANCEUNIT, ELECTRICCHARGEUNIT, ELECTRICCONDUCTANCEUNIT, ELECTRICCURRENTUNIT, ELECTRICRESISTANCEUNIT, ELECTRICVOLTAGEUNIT, ENERGYUNIT, FORCEUNIT, FREQUENCYUNIT, ILLUMINANCEUNIT, INDUCTANCEUNIT, LENGTHUNIT, LUMINOUSFLUXUNIT, LUMINOUSINTENSITYUNIT, MAGNETICFLUXDENSITYUNIT, MAGNETICFLUXUNIT, MASSUNIT, PLANEANGLEUNIT, POWERUNIT, PRESSUREUNIT, RADIOACTIVITYUNIT, SOLIDANGLEUNIT, THERMODYNAMICTEMPERATUREUNIT, TIMEUNIT, VOLUMEUNIT.

Prefixes supported are ATTO, CENTI, DECA, DECI, EXA, FEMTO, GIGA, HECTO, KILO, MEGA, MICRO, MILLI, NANO, PETA, PICO, TERA.

Parameters:

  • unit_type (str) – A type of unit chosen from the list above. For example, choosing LENGTHUNIT will give you a metre.

  • prefix (str,optional) – A prefix chosen from the list above, or None for no prefix.

Returns:

The newly created IfcSIUnit

Return type:

ifcopenshell.entity_instance

Example:

# Millimeters and square meters
length = ifcopenshell.api.unit.add_si_unit(model, unit_type="LENGTHUNIT", prefix="MILLI")
area = ifcopenshell.api.unit.add_si_unit(model, unit_type="AREAUNIT")

# Make it our default units, if we are doing a metric building
ifcopenshell.api.unit.assign_unit(model, units=[length, area])