Package org.djunits.quantity

Class Frequency

java.lang.Object

java.lang.Number

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

org.djunits.quantity.Frequency

All Implemented Interfaces:

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

public class Frequency
extends Quantity<Frequency,Frequency.Unit>

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.

Constructor Summary

Constructors

Constructor	Description
Frequency(double value, String abbreviation)	Instantiate a Frequency quantity with a unit, expressed as a String.
Frequency(double value, Frequency.Unit unit)	Instantiate a Frequency quantity with a unit.
Frequency(Frequency value)	Construct Frequency quantity.

Method Summary

Modifier and Type	Method	Description
final Dimensionless	divide(Frequency v)	Calculate the division of Frequency and Frequency, which results in a Dimensionless quantity.
Frequency	instantiate(double si)	Instantiate a quantity with an SI or base value.
final AngularVelocity	multiply(Angle v)	Calculate the multiplication of Frequency and Angle, which results in a AngularVelocity scalar.
final AngularAcceleration	multiply(AngularVelocity v)	Calculate the multiplication of Frequency and AngularVelocity, which results in a AngularAcceleration scalar.
final Dimensionless	multiply(Duration v)	Calculate the multiplication of Frequency and Duration, which results in a Dimensionless scalar.
final Power	multiply(Energy v)	Calculate the multiplication of Frequency and Energy, which results in a Power scalar.
final Speed	multiply(Length v)	Calculate the multiplication of Frequency and Length, which results in a Speed scalar.
final Acceleration	multiply(Speed v)	Calculate the multiplication of Frequency and Speed, which results in a Acceleration scalar.
static Frequency	of(double value, String unitString)	Returns a Frequency based on a value and the textual representation of the unit, which can be localized.
static Frequency	ofSi(double si)	Return a Frequency instance based on an SI value.
Duration	reciprocal()	Return the reciprocal of this quantity (1/q).
SIUnit	siUnit()	Return the SI unit of this quantity.
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, ge, ge0, getDisplayUnit, getInUnit, getInUnit, getName, gt, gt0, hashCode, instantiate, interpolate, intValue, isRelative, le, le0, longValue, lt, lt0, max, mean, min, multiply, ne, ne0, negate, of, product, scaleBy, setDisplayUnit, si, subtract, sum, toDisplayString, toDisplayString, toString, toString, toString, toString, toStringSIPrefixed, toStringSIPrefixed, toTextualString, toTextualString, 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, setDisplayUnit

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 unit)

Instantiate a Frequency quantity with a unit.

Parameters:

value - the value, expressed in the unit

unit - the unit in which the value is expressed

Frequency

public Frequency(double value,
 String abbreviation)

Instantiate a Frequency quantity with a unit, expressed as a String.

Parameters:

value - the value, expressed in the unit

abbreviation - the String abbreviation of the unit in which the value is expressed

Frequency

public Frequency(Frequency value)

Construct Frequency quantity.

Parameters:

value - Scalar from which to construct this instance

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

instantiate

public Frequency instantiate(double si)

Description copied from class: Quantity

Instantiate a quantity with an SI or base value.

Specified by:

instantiate in class Quantity<Frequency,Frequency.Unit>

Parameters:

si - the value expressed in the base (SI) unit

Returns:

a quantity with the given SI-value and base (SI) unit

siUnit

public SIUnit siUnit()

Description copied from class: Quantity

Return the SI unit of this quantity.

Overrides:

siUnit in class Quantity<Frequency,Frequency.Unit>

Returns:

the SI unit of this quantity

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 value,
 String unitString)

Returns a Frequency based on a value and the textual representation of the unit, which can be localized.

Parameters:

value - the value to use

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

divide

public final 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 final 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 final 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 final 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 final 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 final 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 final 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,Frequency.Unit>

Returns:

the reciprocal of this quantity, with the correct SI units