LuminousFlux.java
package org.djunits.quantity;
import org.djunits.quantity.def.Quantity;
import org.djunits.unit.AbstractUnit;
import org.djunits.unit.UnitInterface;
import org.djunits.unit.UnitRuntimeException;
import org.djunits.unit.Unitless;
import org.djunits.unit.scale.LinearScale;
import org.djunits.unit.scale.Scale;
import org.djunits.unit.si.SIPrefix;
import org.djunits.unit.si.SIUnit;
import org.djunits.unit.system.UnitSystem;
/**
* Luminous flux is the total perceived power of light emitted by a source, measured in lumens (lm).
* <p>
* Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
* for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
* distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
* @author Alexander Verbraeck
*/
public class LuminousFlux extends Quantity<LuminousFlux>
{
/** Constant with value zero. */
public static final LuminousFlux ZERO = ofSi(0.0);
/** Constant with value one. */
public static final LuminousFlux ONE = ofSi(1.0);
/** Constant with value NaN. */
@SuppressWarnings("checkstyle:constantname")
public static final LuminousFlux NaN = ofSi(Double.NaN);
/** Constant with value POSITIVE_INFINITY. */
public static final LuminousFlux POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
/** Constant with value NEGATIVE_INFINITY. */
public static final LuminousFlux NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
/** Constant with value MAX_VALUE. */
public static final LuminousFlux POS_MAXVALUE = ofSi(Double.MAX_VALUE);
/** Constant with value -MAX_VALUE. */
public static final LuminousFlux NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
/** */
private static final long serialVersionUID = 600L;
/**
* Instantiate a LuminousFlux quantity with an SI or base value and a display unit.
* @param value the quantity value expressed in the SI or base unit
* @param displayUnit the display unit to use
* @param useSi use SI value when true, use value in unit when false
*/
public LuminousFlux(final double value, final LuminousFlux.Unit displayUnit, final boolean useSi)
{
super(value, displayUnit, useSi);
}
/**
* Instantiate a LuminousFlux quantity expressed in the given unit.
* @param valueInUnit the quantity value expressed in the given unit
* @param unit the unit of the value, also acts as the display unit
*/
public LuminousFlux(final double valueInUnit, final LuminousFlux.Unit unit)
{
this(valueInUnit, unit, false);
}
/**
* Return a LuminousFlux instance based on an SI value.
* @param si the si value
* @return the LuminousFlux instance based on an SI value
*/
public static LuminousFlux ofSi(final double si)
{
return new LuminousFlux(si, LuminousFlux.Unit.SI, true);
}
/**
* Instantiate a LuminousFlux quantity with an SI or base value and a display unit.
* @param siValue the quantity value expressed in the SI or base unit
* @param displayUnit the display unit to use
* @return the LuminousFlux instance based on an SI value with the given display unit
*/
public static LuminousFlux ofSi(final double siValue, final LuminousFlux.Unit displayUnit)
{
return new LuminousFlux(siValue, displayUnit, true);
}
@Override
public LuminousFlux instantiateSi(final double siValue, final UnitInterface<LuminousFlux> displayUnit)
{
return new LuminousFlux(siValue, (LuminousFlux.Unit) displayUnit, true);
}
/**
* Returns a LuminousFlux 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.
* @param text the textual representation to parse into a LuminousFlux
* @return the Scalar representation of the value in its unit
* @throws IllegalArgumentException when the text cannot be parsed
* @throws NullPointerException when the text argument is null
*/
public static LuminousFlux valueOf(final String text)
{
return Quantity.valueOf(text, ZERO);
}
/**
* Returns a LuminousFlux based on a value expressed in the unit.
* @param valueInUnit the value, expressed in the given unit
* @param unit the unit of the value, also acts as the display unit
* @return ab LuminousFlux representation of the value in its unit
*/
public static LuminousFlux of(final double valueInUnit, final LuminousFlux.Unit unit)
{
return new LuminousFlux(valueInUnit, unit);
}
/**
* Returns a LuminousFlux based on a value and the textual representation of the unit, which can be localized.
* @param valueInUnit the value, expressed in the unit as given by unitString
* @param unitString the textual representation of the unit
* @return the Scalar representation of the value in its unit
* @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
* @throws NullPointerException when the unitString argument is null
*/
public static LuminousFlux of(final double valueInUnit, final String unitString)
{
return Quantity.of(valueInUnit, unitString, ZERO);
}
@Override
public LuminousFlux.Unit getDisplayUnit()
{
return (LuminousFlux.Unit) super.getDisplayUnit();
}
/**
* Calculate the division of LuminousFlux and LuminousFlux, which results in a Dimensionless quantity.
* @param v quantity
* @return quantity as a division of LuminousFlux and LuminousFlux
*/
public Dimensionless divide(final LuminousFlux v)
{
return new Dimensionless(this.si() / v.si(), Unitless.BASE);
}
/**
* Calculate the division of LuminousFlux and Area, which results in a Illuminance scalar.
* @param v scalar
* @return scalar as a division of LuminousFlux and Area
*/
public Illuminance divide(final Area v)
{
return new Illuminance(this.si() / v.si(), Illuminance.Unit.SI);
}
/**
* Calculate the division of LuminousFlux and Illuminance, which results in a Area scalar.
* @param v scalar
* @return scalar as a division of LuminousFlux and Illuminance
*/
public Area divide(final Illuminance v)
{
return new Area(this.si() / v.si(), Area.Unit.SI);
}
/**
* Calculate the division of LuminousFlux and LuminousIntensity, which results in a SolidAngle scalar.
* @param v scalar
* @return scalar as a division of LuminousFlux and LuminousIntensity
*/
public SolidAngle divide(final LuminousIntensity v)
{
return new SolidAngle(this.si() / v.si(), SolidAngle.Unit.SI);
}
/**
* Calculate the division of LuminousFlux and SolidAngle, which results in a LuminousIntensity scalar.
* @param v scalar
* @return scalar as a division of LuminousFlux and SolidAngle
*/
public LuminousIntensity divide(final SolidAngle v)
{
return new LuminousIntensity(this.si() / v.si(), LuminousIntensity.Unit.SI);
}
/******************************************************************************************************/
/********************************************** UNIT CLASS ********************************************/
/******************************************************************************************************/
/**
* LuminousFlux.Unit encodes the units of total perceived power of light emitted by a source.
* <p>
* Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
* See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
* distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
* @author Alexander Verbraeck
*/
@SuppressWarnings("checkstyle:constantname")
public static class Unit extends AbstractUnit<LuminousFlux>
{
/** The dimensions of luminous flux: cd.sr. */
public static final SIUnit SI_UNIT = SIUnit.of("cdsr");
/** Lumen. */
public static final LuminousFlux.Unit lm = new LuminousFlux.Unit("lm", "lumen", 1.0, UnitSystem.SI_DERIVED);
/** The SI or BASE unit. */
public static final LuminousFlux.Unit SI = lm;
/**
* Create a new LuminousFlux unit.
* @param id the id or main abbreviation of the unit
* @param name the full name of the unit
* @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
* @param unitSystem the unit system such as SI or IMPERIAL
*/
public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
{
super(id, name, scaleFactorToBaseUnit, unitSystem);
}
/**
* Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
* @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
* @param displayAbbreviation the display abbreviation of the unit
* @param name the full name of the unit
* @param scale the scale to use to convert from this unit to the standard (e.g., SI, BASE) unit
* @param unitSystem unit system, e.g. SI or Imperial
* @param siPrefix the SI Prefix of this unit
*/
public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
final UnitSystem unitSystem, final SIPrefix siPrefix)
{
super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem, siPrefix);
}
@Override
public SIUnit siUnit()
{
return SI_UNIT;
}
@Override
public Unit getBaseUnit()
{
return SI;
}
@Override
public LuminousFlux ofSi(final double si, final UnitInterface<LuminousFlux> displayUnit)
{
return new LuminousFlux(si, (Unit) displayUnit, true);
}
@Override
public LuminousFlux.Unit deriveUnit(final String abbreviation, final String name, final double scaleFactor,
final UnitSystem unitSystem)
{
return (Unit) super.deriveUnit(abbreviation, name, scaleFactor, unitSystem);
}
@Override
public LuminousFlux.Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation,
final String name, final double scaleFactor, final UnitSystem unitSystem, final SIPrefix siPrefix)
{
if (getScale() instanceof LinearScale ls)
{
return new LuminousFlux.Unit(textualAbbreviation, displayAbbreviation, name,
new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem, siPrefix);
}
throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
}
}
}