Package org.djunits.quantity

Class Illuminance

java.lang.Object
java.lang.Number
org.djunits.quantity.def.Quantity<Illuminance>
org.djunits.quantity.Illuminance
All Implemented Interfaces:
Serializable, Comparable<Illuminance>, Additive<Illuminance>, Scalable<Illuminance>, Value<Illuminance>
public class Illuminance extends Quantity<Illuminance>
Illuminance is the luminous flux incident on a surface per unit area, measured in lux (lx).

Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See for project information https://djunits.org. The DJUNITS project is distributed under a three-clause BSD-style license.

Author:
Alexander Verbraeck
See Also:

  • Field Details

    • ZERO

      public static final Illuminance ZERO
      Constant with value zero.

    • ONE

      public static final Illuminance ONE
      Constant with value one.

    • NaN

      public static final Illuminance NaN
      Constant with value NaN.

    • POSITIVE_INFINITY

      public static final Illuminance POSITIVE_INFINITY
      Constant with value POSITIVE_INFINITY.

    • NEGATIVE_INFINITY

      public static final Illuminance NEGATIVE_INFINITY
      Constant with value NEGATIVE_INFINITY.

    • POS_MAXVALUE

      public static final Illuminance POS_MAXVALUE
      Constant with value MAX_VALUE.

    • NEG_MAXVALUE

      public static final Illuminance NEG_MAXVALUE
      Constant with value -MAX_VALUE.

  • Constructor Details

    • Illuminance

      public Illuminance(double value, Illuminance.Unit displayUnit, boolean useSi)
      Instantiate a Illuminance quantity with an SI or base value and a display unit.
      Parameters:
      value - the quantity value expressed in the SI or base unit
      displayUnit - the display unit to use
      useSi - use SI value when true, use value in unit when false

    • Illuminance

      public Illuminance(double valueInUnit, Illuminance.Unit unit)
      Instantiate a Illuminance quantity expressed in the given unit.
      Parameters:
      valueInUnit - the quantity value expressed in the given unit
      unit - the unit of the value, also acts as the display unit

  • Method Details

    • ofSi

      public static Illuminance ofSi(double si)
      Return a Illuminance instance based on an SI value.
      Parameters:
      si - the si value
      Returns:
      the Illuminance instance based on an SI value

    • ofSi

      public static Illuminance ofSi(double siValue, Illuminance.Unit displayUnit)
      Instantiate a Illuminance quantity with an SI or base value and a display unit.
      Parameters:
      siValue - the quantity value expressed in the SI or base unit
      displayUnit - the display unit to use
      Returns:
      the Illuminance instance based on an SI value with the given display unit

    • instantiateSi

      public Illuminance instantiateSi(double siValue, UnitInterface<Illuminance> displayUnit)
      Description copied from class: Quantity
      Instantiate a quantity with an SI or base value, and a display unit.
      Specified by:
      instantiateSi in class Quantity<Illuminance>
      Parameters:
      siValue - the value expressed in the base (SI) unit
      displayUnit - the display unit to use for the quantity
      Returns:
      a quantity with the given SI or base value, and the given display unit

    • valueOf

      public static Illuminance valueOf(String text)
      Returns a Illuminance representation of a textual representation of a value with a unit. The String representation that can be parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed, but not required, between the value and the unit.
      Parameters:
      text - the textual representation to parse into a Illuminance
      Returns:
      the Scalar representation of the value in its unit
      Throws:
      IllegalArgumentException - when the text cannot be parsed
      NullPointerException - when the text argument is null

    • of

      public static Illuminance of(double valueInUnit, Illuminance.Unit unit)
      Returns a Illuminance based on a value expressed in the unit.
      Parameters:
      valueInUnit - the value, expressed in the given unit
      unit - the unit of the value, also acts as the display unit
      Returns:
      ab Illuminance representation of the value in its unit

    • of

      public static Illuminance of(double valueInUnit, String unitString)
      Returns a Illuminance based on a value and the textual representation of the unit, which can be localized.
      Parameters:
      valueInUnit - the value, expressed in the unit as given by unitString
      unitString - the textual representation of the unit
      Returns:
      the Scalar representation of the value in its unit
      Throws:
      IllegalArgumentException - when the unit cannot be parsed or is incorrect
      NullPointerException - when the unitString argument is null

    • getDisplayUnit

      public Illuminance.Unit getDisplayUnit()
      Description copied from interface: Value
      Retrieve the unit of this Value.
      Specified by:
      getDisplayUnit in interface Value<Illuminance>
      Overrides:
      getDisplayUnit in class Quantity<Illuminance>
      Returns:
      the unit of this Value

    • divide

      public Dimensionless divide(Illuminance v)
      Calculate the division of Illuminance and Illuminance, which results in a Dimensionless quantity.
      Parameters:
      v - quantity
      Returns:
      quantity as a division of Illuminance and Illuminance

    • multiply

      public LuminousFlux multiply(Area v)
      Calculate the multiplication of Illuminance and Area, which results in a LuminousFlux scalar.
      Parameters:
      v - scalar
      Returns:
      scalar as a multiplication of Illuminance and Area