Package org.djunits.quantity

Class ArealObjectDensity

java.lang.Object

java.lang.Number

org.djunits.quantity.def.Quantity<ArealObjectDensity>

org.djunits.quantity.ArealObjectDensity

All Implemented Interfaces:

Serializable, Comparable<ArealObjectDensity>, Additive<ArealObjectDensity>, Scalable<ArealObjectDensity>, Value<ArealObjectDensity>

public class ArealObjectDensity
extends Quantity<ArealObjectDensity>

Areal object density counts the number of objects per unit of area, measured in number per square meter (/m2).

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:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ArealObjectDensity.Unit	ArealObjectDensity.Unit encodes the unit for number of objects per unit of area.

Field Summary

Fields

Modifier and Type	Field	Description
static final ArealObjectDensity	NaN	Constant with value NaN.
static final ArealObjectDensity	NEG_MAXVALUE	Constant with value -MAX_VALUE.
static final ArealObjectDensity	NEGATIVE_INFINITY	Constant with value NEGATIVE_INFINITY.
static final ArealObjectDensity	ONE	Constant with value one.
static final ArealObjectDensity	POS_MAXVALUE	Constant with value MAX_VALUE.
static final ArealObjectDensity	POSITIVE_INFINITY	Constant with value POSITIVE_INFINITY.
static final ArealObjectDensity	ZERO	Constant with value zero.

Fields inherited from class org.djunits.quantity.def.Quantity

si

Constructor Summary

Constructors

Constructor	Description
ArealObjectDensity(double valueInUnit, ArealObjectDensity.Unit unit)	Instantiate a ArealObjectDensity quantity expressed in the given unit.
ArealObjectDensity(double value, ArealObjectDensity.Unit displayUnit, boolean useSi)	Instantiate a ArealObjectDensity quantity with an SI or base value and a display unit.

Method Summary

Modifier and Type	Method	Description
Dimensionless	divide(ArealObjectDensity other)	Divides this areal object density by another areal object density to yield a dimensionless ratio.
VolumetricObjectDensity	divide(Length length)	Divides this areal object density by a length to yield a volumetric object density.
Length	divide(VolumetricObjectDensity vod)	Divides this areal object density by a volumetric object density to yield a length.
ArealObjectDensity.Unit	getDisplayUnit()	Retrieve the unit of this Value.
ArealObjectDensity	instantiateSi(double siValue, UnitInterface<ArealObjectDensity> displayUnit)	Instantiate a quantity with an SI or base value, and a display unit.
Dimensionless	multiply(Area area)	Multiplies this areal object density by an area to yield a dimensionless count.
LinearObjectDensity	multiply(Length length)	Multiplies this areal object density by a length to yield a linear object density.
static ArealObjectDensity	of(double valueInUnit, String unitString)	Returns a ArealObjectDensity based on a value and the textual representation of the unit, which can be localized.
static ArealObjectDensity	of(double valueInUnit, ArealObjectDensity.Unit unit)	Returns a ArealObjectDensity based on a value expressed in the unit.
static ArealObjectDensity	ofSi(double si)	Return a ArealObjectDensity instance based on an SI value.
static ArealObjectDensity	ofSi(double siValue, ArealObjectDensity.Unit displayUnit)	Instantiate a ArealObjectDensity quantity with an SI or base value and a display unit.
Area	reciprocal()	Return the reciprocal of this quantity (1/q).
static ArealObjectDensity	valueOf(String text)	Returns a ArealObjectDensity representation of a textual representation of a value with a unit.

Methods inherited from class org.djunits.quantity.def.Quantity

abs, add, as, compareTo, divide, doubleValue, eq, eq0, equals, floatValue, format, format, format, ge, ge0, getInUnit, getInUnit, getName, gt, gt0, hashCode, instantiate, instantiateSi, interpolate, intValue, isRelative, le, le0, longValue, lt, lt0, max, mean, min, multiply, ne, ne0, negate, of, product, scaleBy, si, siUnit, subtract, sum, toString, valueOf

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.djunits.value.Scalable

divideBy

Methods inherited from interface org.djunits.value.Value

isAbsolute

Field Details

ZERO

public static final ArealObjectDensity ZERO

Constant with value zero.

ONE

public static final ArealObjectDensity ONE

Constant with value one.

NaN

public static final ArealObjectDensity NaN

Constant with value NaN.

POSITIVE_INFINITY

public static final ArealObjectDensity POSITIVE_INFINITY

Constant with value POSITIVE_INFINITY.

NEGATIVE_INFINITY

public static final ArealObjectDensity NEGATIVE_INFINITY

Constant with value NEGATIVE_INFINITY.

POS_MAXVALUE

public static final ArealObjectDensity POS_MAXVALUE

Constant with value MAX_VALUE.

NEG_MAXVALUE

public static final ArealObjectDensity NEG_MAXVALUE

Constant with value -MAX_VALUE.

Constructor Details

ArealObjectDensity

public ArealObjectDensity(double value,
 ArealObjectDensity.Unit displayUnit,
 boolean useSi)

Instantiate a ArealObjectDensity 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

ArealObjectDensity

public ArealObjectDensity(double valueInUnit,
 ArealObjectDensity.Unit unit)

Instantiate a ArealObjectDensity 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 ArealObjectDensity ofSi(double si)

Return a ArealObjectDensity instance based on an SI value.

Parameters:

si - the si value

Returns:

the ArealObjectDensity instance based on an SI value

ofSi

public static ArealObjectDensity ofSi(double siValue,
 ArealObjectDensity.Unit displayUnit)

Instantiate a ArealObjectDensity 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 ArealObjectDensity instance based on an SI value with the given display unit

instantiateSi

public ArealObjectDensity instantiateSi(double siValue,
 UnitInterface<ArealObjectDensity> 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<ArealObjectDensity>

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 ArealObjectDensity valueOf(String text)

Returns a ArealObjectDensity 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 ArealObjectDensity

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 ArealObjectDensity of(double valueInUnit,
 ArealObjectDensity.Unit unit)

Returns a ArealObjectDensity 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 ArealObjectDensity representation of the value in its unit

of

public static ArealObjectDensity of(double valueInUnit,
 String unitString)

Returns a ArealObjectDensity 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 ArealObjectDensity.Unit getDisplayUnit()

Description copied from interface: Value

Retrieve the unit of this Value.

Specified by:

getDisplayUnit in interface Value<ArealObjectDensity>

Overrides:

getDisplayUnit in class Quantity<ArealObjectDensity>

Returns:

the unit of this Value

divide

public Dimensionless divide(ArealObjectDensity other)

Divides this areal object density by another areal object density to yield a dimensionless ratio.

Formula: (1/m²) / (1/m²) = 1.

Parameters:

other - the areal object density divisor; must not be null.

Returns:

the resulting dimensionless ratio in SI (1).

Throws:

NullPointerException - if other is null.

multiply

public Dimensionless multiply(Area area)

Multiplies this areal object density by an area to yield a dimensionless count.

Formula: (1/m²) x m² = 1.

Parameters:

area - the area multiplier; must not be null.

Returns:

the resulting dimensionless count in SI (1).

Throws:

NullPointerException - if area is null.

multiply

public LinearObjectDensity multiply(Length length)

Multiplies this areal object density by a length to yield a linear object density.

Formula: (1/m²) x m = 1/m.

Parameters:

length - the length multiplier; must not be null.

Returns:

the resulting linear object density in SI (1/m).

Throws:

NullPointerException - if length is null.

divide

public VolumetricObjectDensity divide(Length length)

Divides this areal object density by a length to yield a volumetric object density.

Formula: (1/m²) / m = 1/m³.

Parameters:

length - the length divisor; must not be null.

Returns:

the resulting volumetric object density in SI (1/m³).

Throws:

NullPointerException - if length is null.

divide

public Length divide(VolumetricObjectDensity vod)

Divides this areal object density by a volumetric object density to yield a length.

Formula: (1/m²) / (1/m³) = m.

Parameters:

vod - the volumetric object density divisor; must not be null.

Returns:

the resulting length in SI (m).

Throws:

NullPointerException - if vod is null.

reciprocal

public Area reciprocal()

Description copied from class: Quantity

Return the reciprocal of this quantity (1/q).

Overrides:

reciprocal in class Quantity<ArealObjectDensity>

Returns:

the reciprocal of this quantity, with the correct SI units