Package org.djunits.quantity

Class Speed

java.lang.Object

java.lang.Number

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

org.djunits.quantity.Speed

All Implemented Interfaces:

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

public class Speed
extends Quantity<Speed>

Speed is the rate of change of position over time.

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	Speed.Unit	Speed.Unit encodes the units of the rate of change of a position over time.

Field Summary

Fields

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

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

si

Constructor Summary

Constructors

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

Method Summary

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

Constant with value zero.

ONE

public static final Speed ONE

Constant with value one.

NaN

public static final Speed NaN

Constant with value NaN.

POSITIVE_INFINITY

public static final Speed POSITIVE_INFINITY

Constant with value POSITIVE_INFINITY.

NEGATIVE_INFINITY

public static final Speed NEGATIVE_INFINITY

Constant with value NEGATIVE_INFINITY.

POS_MAXVALUE

public static final Speed POS_MAXVALUE

Constant with value MAX_VALUE.

NEG_MAXVALUE

public static final Speed NEG_MAXVALUE

Constant with value -MAX_VALUE.

Constructor Details

Speed

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

Instantiate a Speed 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

Speed

public Speed(double valueInUnit,
 Speed.Unit unit)

Instantiate a Speed 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 Speed ofSi(double si)

Return a Speed instance based on an SI value.

Parameters:

si - the si value

Returns:

the Speed instance based on an SI value

ofSi

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

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

instantiateSi

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

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 Speed valueOf(String text)

Returns a Speed 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 Speed

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 Speed of(double valueInUnit,
 Speed.Unit unit)

Returns a Speed 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 Speed representation of the value in its unit

of

public static Speed of(double valueInUnit,
 String unitString)

Returns a Speed 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 Speed.Unit getDisplayUnit()

Description copied from interface: Value

Retrieve the unit of this Value.

Specified by:

getDisplayUnit in interface Value<Speed>

Overrides:

getDisplayUnit in class Quantity<Speed>

Returns:

the unit of this Value

divide

public Dimensionless divide(Speed v)

Calculate the division of Speed and Speed, which results in a Dimensionless scalar.

Parameters:

v - scalar

Returns:

scalar as a division of Speed and Speed

multiply

public FlowVolume multiply(Area v)

Calculate the multiplication of Speed and Area, which results in a FlowVolume scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and Area

multiply

public Power multiply(Force v)

Calculate the multiplication of Speed and Force, which results in a Power scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and Force

multiply

public Acceleration multiply(Frequency v)

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

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and Frequency

divide

public Frequency divide(Length v)

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

Parameters:

v - scalar

Returns:

scalar as a division of Speed and Length

divide

public Length divide(Frequency v)

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

Parameters:

v - scalar

Returns:

scalar as a division of Speed and Frequency

multiply

public Frequency multiply(LinearObjectDensity v)

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

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and LinearObjectDensity

multiply

public Length multiply(Duration v)

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

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and Duration

divide

public Acceleration divide(Duration v)

Calculate the division of Speed and Duration, which results in a Acceleration scalar.

Parameters:

v - scalar

Returns:

scalar as a division of Speed and Duration

divide

public Duration divide(Acceleration v)

Calculate the division of Speed and Acceleration, which results in a Duration scalar.

Parameters:

v - scalar

Returns:

scalar as a division of Speed and Acceleration

multiply

public Force multiply(FlowMass v)

Calculate the multiplication of Speed and FlowMass, which results in a Force scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and FlowMass

multiply

public Momentum multiply(Mass v)

Calculate the multiplication of Speed and Mass, which results in a Momentum scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and Mass

multiply

public Energy multiply(Momentum v)

Calculate the multiplication of Speed and Momentum, which results in a Energy scalar.

Parameters:

v - scalar

Returns:

scalar as a multiplication of Speed and Momentum