Package org.djunits.quantity

Class Frequency

java.lang.Object

java.lang.Number

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

org.djunits.quantity.Frequency

All Implemented Interfaces:

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

public class Frequency
extends Quantity<Frequency>

Frequency encodes the number of events per unit of duration.

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	Frequency.Unit	Frequency.Unit encodes the units of frequency.

Field Summary

Fields

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

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

si

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
Dimensionless	divide(Frequency v)	Calculate the division of Frequency and Frequency, which results in a Dimensionless quantity.
Frequency.Unit	getDisplayUnit()	Retrieve the unit of this Value.
Frequency	instantiateSi(double siValue, UnitInterface<Frequency> displayUnit)	Instantiate a quantity with an SI or base value, and a display unit.
AngularVelocity	multiply(Angle v)	Calculate the multiplication of Frequency and Angle, which results in a AngularVelocity scalar.
AngularAcceleration	multiply(AngularVelocity v)	Calculate the multiplication of Frequency and AngularVelocity, which results in a AngularAcceleration scalar.
Dimensionless	multiply(Duration v)	Calculate the multiplication of Frequency and Duration, which results in a Dimensionless scalar.
Power	multiply(Energy v)	Calculate the multiplication of Frequency and Energy, which results in a Power scalar.
Speed	multiply(Length v)	Calculate the multiplication of Frequency and Length, which results in a Speed scalar.
Acceleration	multiply(Speed v)	Calculate the multiplication of Frequency and Speed, which results in a Acceleration scalar.
static Frequency	of(double valueInUnit, String unitString)	Returns a Frequency based on a value and the textual representation of the unit, which can be localized.
static Frequency	of(double valueInUnit, Frequency.Unit unit)	Returns a Frequency based on a value expressed in the unit.
static Frequency	ofSi(double si)	Return a Frequency instance based on an SI value.
static Frequency	ofSi(double siValue, Frequency.Unit displayUnit)	Instantiate a Frequency quantity with an SI or base value and a display unit.
Duration	reciprocal()	Return the reciprocal of this quantity (1/q).
static Frequency	valueOf(String text)	Returns a Frequency 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 Frequency ZERO

Constant with value zero.

ONE

public static final Frequency ONE

Constant with value one.

NaN

public static final Frequency NaN

Constant with value NaN.

POSITIVE_INFINITY

public static final Frequency POSITIVE_INFINITY

Constant with value POSITIVE_INFINITY.

NEGATIVE_INFINITY

public static final Frequency NEGATIVE_INFINITY

Constant with value NEGATIVE_INFINITY.

POS_MAXVALUE

public static final Frequency POS_MAXVALUE

Constant with value MAX_VALUE.

NEG_MAXVALUE

public static final Frequency NEG_MAXVALUE

Constant with value -MAX_VALUE.

Constructor Details

Frequency

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

Instantiate a Frequency 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

Frequency

public Frequency(double valueInUnit,
 Frequency.Unit unit)

Instantiate a Frequency 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 Frequency ofSi(double si)

Return a Frequency instance based on an SI value.

Parameters:

si - the si value

Returns:

the Frequency instance based on an SI value

ofSi

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

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

instantiateSi

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

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 Frequency valueOf(String text)

Returns a Frequency 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 Frequency

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 Frequency of(double valueInUnit,
 Frequency.Unit unit)

Returns a Frequency 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 Frequency representation of the value in its unit

of

public static Frequency of(double valueInUnit,
 String unitString)

Returns a Frequency 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 Frequency.Unit getDisplayUnit()

Description copied from interface: Value

Retrieve the unit of this Value.

Specified by:

getDisplayUnit in interface Value<Frequency>

Overrides:

getDisplayUnit in class Quantity<Frequency>

Returns:

the unit of this Value

divide

public Dimensionless divide(Frequency v)

Calculate the division of Frequency and Frequency, which results in a Dimensionless quantity.

Parameters:

v - quantity

Returns:

quantity as a division of Frequency and Frequency

multiply

public Dimensionless multiply(Duration v)

Calculate the multiplication of Frequency and Duration, which results in a Dimensionless scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Frequency and Duration

multiply

public Speed multiply(Length v)

Calculate the multiplication of Frequency and Length, which results in a Speed scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Frequency and Length

multiply

public Acceleration multiply(Speed v)

Calculate the multiplication of Frequency and Speed, which results in a Acceleration scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Frequency and Speed

multiply

public Power multiply(Energy v)

Calculate the multiplication of Frequency and Energy, which results in a Power scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Frequency and Energy

multiply

public AngularVelocity multiply(Angle v)

Calculate the multiplication of Frequency and Angle, which results in a AngularVelocity scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Frequency and Angle

multiply

public AngularAcceleration multiply(AngularVelocity v)

Calculate the multiplication of Frequency and AngularVelocity, which results in a AngularAcceleration scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Frequency and AngularVelocity

reciprocal

public Duration reciprocal()

Description copied from class: Quantity

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

Overrides:

reciprocal in class Quantity<Frequency>

Returns:

the reciprocal of this quantity, with the correct SI units