Acceleration.java
package org.djunits.quantity;
import org.djunits.quantity.def.Quantity;
import org.djunits.unit.AbstractUnit;
import org.djunits.unit.UnitRuntimeException;
import org.djunits.unit.Unitless;
import org.djunits.unit.Units;
import org.djunits.unit.scale.LinearScale;
import org.djunits.unit.scale.Scale;
import org.djunits.unit.si.SIUnit;
import org.djunits.unit.system.UnitSystem;
/**
* Acceleration is the rate of change of velocity over time, measured in meters per second squared (m/s2).
* <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 Acceleration extends Quantity<Acceleration, Acceleration.Unit>
{
/** Constant with value zero. */
public static final Acceleration ZERO = Acceleration.ofSi(0.0);
/** Constant with value one. */
public static final Acceleration ONE = Acceleration.ofSi(1.0);
/** Constant with value NaN. */
@SuppressWarnings("checkstyle:constantname")
public static final Acceleration NaN = Acceleration.ofSi(Double.NaN);
/** Constant with value POSITIVE_INFINITY. */
public static final Acceleration POSITIVE_INFINITY = Acceleration.ofSi(Double.POSITIVE_INFINITY);
/** Constant with value NEGATIVE_INFINITY. */
public static final Acceleration NEGATIVE_INFINITY = Acceleration.ofSi(Double.NEGATIVE_INFINITY);
/** Constant with value MAX_VALUE. */
public static final Acceleration POS_MAXVALUE = Acceleration.ofSi(Double.MAX_VALUE);
/** Constant with value -MAX_VALUE. */
public static final Acceleration NEG_MAXVALUE = Acceleration.ofSi(-Double.MAX_VALUE);
/** */
private static final long serialVersionUID = 600L;
/**
* Instantiate a Acceleration quantity with a unit.
* @param value the value, expressed in the unit
* @param unit the unit in which the value is expressed
*/
public Acceleration(final double value, final Acceleration.Unit unit)
{
super(value, unit);
}
/**
* Instantiate a Acceleration quantity with a unit, expressed as a String.
* @param value the value, expressed in the unit
* @param abbreviation the String abbreviation of the unit in which the value is expressed
*/
public Acceleration(final double value, final String abbreviation)
{
this(value, Units.resolve(Acceleration.Unit.class, abbreviation));
}
/**
* Construct Acceleration quantity.
* @param value Scalar from which to construct this instance
*/
public Acceleration(final Acceleration value)
{
super(value.si(), Acceleration.Unit.SI);
setDisplayUnit(value.getDisplayUnit());
}
/**
* Return a Acceleration instance based on an SI value.
* @param si the si value
* @return the Acceleration instance based on an SI value
*/
public static Acceleration ofSi(final double si)
{
return new Acceleration(si, Acceleration.Unit.SI);
}
@Override
public Acceleration instantiate(final double si)
{
return ofSi(si);
}
@Override
public SIUnit siUnit()
{
return Acceleration.Unit.SI_UNIT;
}
/**
* Returns a Acceleration 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 Acceleration
* @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 Acceleration valueOf(final String text)
{
return Quantity.valueOf(text, ZERO);
}
/**
* Returns a Acceleration based on a value and the textual representation of the unit, which can be localized.
* @param value the value to use
* @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 Acceleration of(final double value, final String unitString)
{
return Quantity.of(value, unitString, ZERO);
}
/**
* Calculate the division of Acceleration and Acceleration, which results in a Dimensionless scalar.
* @param v scalar
* @return scalar as a division of Acceleration and Acceleration
*/
public final Dimensionless divide(final Acceleration v)
{
return new Dimensionless(this.si() / v.si(), Unitless.BASE);
}
/**
* Calculate the multiplication of Acceleration and Mass, which results in a Force scalar.
* @param v scalar
* @return scalar as a multiplication of Acceleration and Mass
*/
public final Force multiply(final Mass v)
{
return new Force(this.si() * v.si(), Force.Unit.SI);
}
/**
* Calculate the multiplication of Acceleration and Duration, which results in a Speed scalar.
* @param v scalar
* @return scalar as a multiplication of Acceleration and Duration
*/
public final Speed multiply(final Duration v)
{
return new Speed(this.si() * v.si(), Speed.Unit.SI);
}
/**
* Calculate the division of Acceleration and Frequency, which results in a Speed scalar.
* @param v scalar
* @return scalar as a division of Acceleration and Frequency
*/
public final Speed divide(final Frequency v)
{
return new Speed(this.si() / v.si(), Speed.Unit.SI);
}
/**
* Calculate the division of Acceleration and Speed, which results in a Frequency scalar.
* @param v scalar
* @return scalar as a division of Acceleration and Speed
*/
public final Frequency divide(final Speed v)
{
return new Frequency(this.si() / v.si(), Frequency.Unit.SI);
}
/**
* Calculate the multiplication of Acceleration and Momentum, which results in a Power scalar.
* @param v scalar
* @return scalar as a multiplication of Acceleration and Momentum
*/
public final Power multiply(final Momentum v)
{
return new Power(this.si() * v.si(), Power.Unit.SI);
}
/******************************************************************************************************/
/********************************************** UNIT CLASS ********************************************/
/******************************************************************************************************/
/**
* Acceleration.Unit encodes the units of acceleration.
* <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<Acceleration.Unit, Acceleration>
{
/** Constant for standard gravity. */
public static final double CONST_GRAVITY = 9.80665;
/** The dimensions of Acceleration: m/s2. */
public static final SIUnit SI_UNIT = SIUnit.of("m/s2");
/** m/s2. */
public static final Acceleration.Unit m_s2 =
new Acceleration.Unit("m/s2", "meter per second squared", 1.0, UnitSystem.SI_DERIVED);
/** The SI or BASE unit. */
public static final Acceleration.Unit SI = m_s2;
/** km/h2. */
public static final Acceleration.Unit km_h2 = new Acceleration.Unit("km/h2", "kilometer per hour squared",
1000.0 / (3600.0 * 3600.0), UnitSystem.SI_ACCEPTED);
/** ft/s2. */
public static final Acceleration.Unit ft_s2 =
new Acceleration.Unit("ft/s2", "foot per second squared", Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
/** in/s2. */
public static final Acceleration.Unit in_s2 =
new Acceleration.Unit("in/s2", "inch per second squared", Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
/** mi/h2. */
public static final Acceleration.Unit mi_h2 = new Acceleration.Unit("mi/h2", "mile per hour squared",
Length.Unit.CONST_MI / (3600.0 * 3600.0), UnitSystem.IMPERIAL);
/** mi/s2. */
public static final Acceleration.Unit mi_s2 =
new Acceleration.Unit("mi/s2", "mile per second squared", Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
/** kt/s = Nautical Mile / h / s. */
public static final Acceleration.Unit kt_s =
new Acceleration.Unit("kt/s", "knot per second", Length.Unit.CONST_NM / 3600.0, UnitSystem.OTHER);
/** mi/h/s. */
public static final Acceleration.Unit mi_h_s =
new Acceleration.Unit("mi/h/s", "mile per hour per second", Length.Unit.CONST_MI / 3600.0, UnitSystem.IMPERIAL);
/** The standard gravity. */
public static final Acceleration.Unit g =
new Acceleration.Unit("g", "standard gravity", CONST_GRAVITY, UnitSystem.OTHER);
/** Gal or cm/s. */
public static final Acceleration.Unit Gal = new Acceleration.Unit("Gal", "gal", 0.01, UnitSystem.CGS);
/**
* Create a new Acceleration 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, new LinearScale(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 between this unit and the standard (e.g., SI, BASE) unit
* @param unitSystem unit system, e.g. SI or Imperial
*/
public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
final UnitSystem unitSystem)
{
super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
}
@Override
public SIUnit siUnit()
{
return SI_UNIT;
}
@Override
public Unit getBaseUnit()
{
return SI;
}
@Override
public Acceleration ofSi(final double si)
{
return Acceleration.ofSi(si);
}
@Override
public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
final double scaleFactor, final UnitSystem unitSystem)
{
if (getScale() instanceof LinearScale ls)
{
return new Acceleration.Unit(textualAbbreviation, displayAbbreviation, name,
new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
}
throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
}
}
}