1 package org.djunits.quantity;
2
3 import org.djunits.quantity.def.Quantity;
4 import org.djunits.unit.AbstractUnit;
5 import org.djunits.unit.UnitRuntimeException;
6 import org.djunits.unit.Unitless;
7 import org.djunits.unit.Units;
8 import org.djunits.unit.scale.LinearScale;
9 import org.djunits.unit.scale.Scale;
10 import org.djunits.unit.si.SIUnit;
11 import org.djunits.unit.system.UnitSystem;
12
13 /**
14 * Acceleration is the rate of change of velocity over time, measured in meters per second squared (m/s2).
15 * <p>
16 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
17 * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
18 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
19 * @author Alexander Verbraeck
20 */
21 public class Acceleration extends Quantity<Acceleration, Acceleration.Unit>
22 {
23 /** Constant with value zero. */
24 public static final Acceleration ZERO = Acceleration.ofSi(0.0);
25
26 /** Constant with value one. */
27 public static final Acceleration ONE = Acceleration.ofSi(1.0);
28
29 /** Constant with value NaN. */
30 @SuppressWarnings("checkstyle:constantname")
31 public static final Acceleration NaN = Acceleration.ofSi(Double.NaN);
32
33 /** Constant with value POSITIVE_INFINITY. */
34 public static final Acceleration POSITIVE_INFINITY = Acceleration.ofSi(Double.POSITIVE_INFINITY);
35
36 /** Constant with value NEGATIVE_INFINITY. */
37 public static final Acceleration NEGATIVE_INFINITY = Acceleration.ofSi(Double.NEGATIVE_INFINITY);
38
39 /** Constant with value MAX_VALUE. */
40 public static final Acceleration POS_MAXVALUE = Acceleration.ofSi(Double.MAX_VALUE);
41
42 /** Constant with value -MAX_VALUE. */
43 public static final Acceleration NEG_MAXVALUE = Acceleration.ofSi(-Double.MAX_VALUE);
44
45 /** */
46 private static final long serialVersionUID = 600L;
47
48 /**
49 * Instantiate a Acceleration quantity with a unit.
50 * @param value the value, expressed in the unit
51 * @param unit the unit in which the value is expressed
52 */
53 public Acceleration(final double value, final Acceleration.Unit unit)
54 {
55 super(value, unit);
56 }
57
58 /**
59 * Instantiate a Acceleration quantity with a unit, expressed as a String.
60 * @param value the value, expressed in the unit
61 * @param abbreviation the String abbreviation of the unit in which the value is expressed
62 */
63 public Acceleration(final double value, final String abbreviation)
64 {
65 this(value, Units.resolve(Acceleration.Unit.class, abbreviation));
66 }
67
68 /**
69 * Construct Acceleration quantity.
70 * @param value Scalar from which to construct this instance
71 */
72 public Acceleration(final Acceleration value)
73 {
74 super(value.si(), Acceleration.Unit.SI);
75 setDisplayUnit(value.getDisplayUnit());
76 }
77
78 /**
79 * Return a Acceleration instance based on an SI value.
80 * @param si the si value
81 * @return the Acceleration instance based on an SI value
82 */
83 public static Acceleration ofSi(final double si)
84 {
85 return new Acceleration(si, Acceleration.Unit.SI);
86 }
87
88 @Override
89 public Acceleration instantiate(final double si)
90 {
91 return ofSi(si);
92 }
93
94 @Override
95 public SIUnit siUnit()
96 {
97 return Acceleration.Unit.SI_UNIT;
98 }
99
100 /**
101 * Returns a Acceleration representation of a textual representation of a value with a unit. The String representation that
102 * can be parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are
103 * allowed, but not required, between the value and the unit.
104 * @param text the textual representation to parse into a Acceleration
105 * @return the Scalar representation of the value in its unit
106 * @throws IllegalArgumentException when the text cannot be parsed
107 * @throws NullPointerException when the text argument is null
108 */
109 public static Acceleration valueOf(final String text)
110 {
111 return Quantity.valueOf(text, ZERO);
112 }
113
114 /**
115 * Returns a Acceleration based on a value and the textual representation of the unit, which can be localized.
116 * @param value the value to use
117 * @param unitString the textual representation of the unit
118 * @return the Scalar representation of the value in its unit
119 * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
120 * @throws NullPointerException when the unitString argument is null
121 */
122 public static Acceleration of(final double value, final String unitString)
123 {
124 return Quantity.of(value, unitString, ZERO);
125 }
126
127 /**
128 * Calculate the division of Acceleration and Acceleration, which results in a Dimensionless scalar.
129 * @param v scalar
130 * @return scalar as a division of Acceleration and Acceleration
131 */
132 public final Dimensionless divide(final Acceleration v)
133 {
134 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
135 }
136
137 /**
138 * Calculate the multiplication of Acceleration and Mass, which results in a Force scalar.
139 * @param v scalar
140 * @return scalar as a multiplication of Acceleration and Mass
141 */
142 public final Force multiply(final Mass v)
143 {
144 return new Force(this.si() * v.si(), Force.Unit.SI);
145 }
146
147 /**
148 * Calculate the multiplication of Acceleration and Duration, which results in a Speed scalar.
149 * @param v scalar
150 * @return scalar as a multiplication of Acceleration and Duration
151 */
152 public final Speed multiply(final Duration v)
153 {
154 return new Speed(this.si() * v.si(), Speed.Unit.SI);
155 }
156
157 /**
158 * Calculate the division of Acceleration and Frequency, which results in a Speed scalar.
159 * @param v scalar
160 * @return scalar as a division of Acceleration and Frequency
161 */
162 public final Speed divide(final Frequency v)
163 {
164 return new Speed(this.si() / v.si(), Speed.Unit.SI);
165 }
166
167 /**
168 * Calculate the division of Acceleration and Speed, which results in a Frequency scalar.
169 * @param v scalar
170 * @return scalar as a division of Acceleration and Speed
171 */
172 public final Frequency divide(final Speed v)
173 {
174 return new Frequency(this.si() / v.si(), Frequency.Unit.SI);
175 }
176
177 /**
178 * Calculate the multiplication of Acceleration and Momentum, which results in a Power scalar.
179 * @param v scalar
180 * @return scalar as a multiplication of Acceleration and Momentum
181 */
182 public final Power multiply(final Momentum v)
183 {
184 return new Power(this.si() * v.si(), Power.Unit.SI);
185 }
186
187 /******************************************************************************************************/
188 /********************************************** UNIT CLASS ********************************************/
189 /******************************************************************************************************/
190
191 /**
192 * Acceleration.Unit encodes the units of acceleration.
193 * <p>
194 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
195 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
196 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
197 * @author Alexander Verbraeck
198 */
199 @SuppressWarnings("checkstyle:constantname")
200 public static class Unit extends AbstractUnit<Acceleration.Unit, Acceleration>
201 {
202 /** Constant for standard gravity. */
203 public static final double CONST_GRAVITY = 9.80665;
204
205 /** The dimensions of Acceleration: m/s2. */
206 public static final SIUnit SI_UNIT = SIUnit.of("m/s2");
207
208 /** m/s2. */
209 public static final Acceleration.Unit m_s2 =
210 new Acceleration.Unit("m/s2", "meter per second squared", 1.0, UnitSystem.SI_DERIVED);
211
212 /** The SI or BASE unit. */
213 public static final Acceleration.Unit SI = m_s2;
214
215 /** km/h2. */
216 public static final Acceleration.Unit km_h2 = new Acceleration.Unit("km/h2", "kilometer per hour squared",
217 1000.0 / (3600.0 * 3600.0), UnitSystem.SI_ACCEPTED);
218
219 /** ft/s2. */
220 public static final Acceleration.Unit ft_s2 =
221 new Acceleration.Unit("ft/s2", "foot per second squared", Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
222
223 /** in/s2. */
224 public static final Acceleration.Unit in_s2 =
225 new Acceleration.Unit("in/s2", "inch per second squared", Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
226
227 /** mi/h2. */
228 public static final Acceleration.Unit mi_h2 = new Acceleration.Unit("mi/h2", "mile per hour squared",
229 Length.Unit.CONST_MI / (3600.0 * 3600.0), UnitSystem.IMPERIAL);
230
231 /** mi/s2. */
232 public static final Acceleration.Unit mi_s2 =
233 new Acceleration.Unit("mi/s2", "mile per second squared", Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
234
235 /** kt/s = Nautical Mile / h / s. */
236 public static final Acceleration.Unit kt_s =
237 new Acceleration.Unit("kt/s", "knot per second", Length.Unit.CONST_NM / 3600.0, UnitSystem.OTHER);
238
239 /** mi/h/s. */
240 public static final Acceleration.Unit mi_h_s =
241 new Acceleration.Unit("mi/h/s", "mile per hour per second", Length.Unit.CONST_MI / 3600.0, UnitSystem.IMPERIAL);
242
243 /** The standard gravity. */
244 public static final Acceleration.Unit g =
245 new Acceleration.Unit("g", "standard gravity", CONST_GRAVITY, UnitSystem.OTHER);
246
247 /** Gal or cm/s. */
248 public static final Acceleration.Unit Gal = new Acceleration.Unit("Gal", "gal", 0.01, UnitSystem.CGS);
249
250 /**
251 * Create a new Acceleration unit.
252 * @param id the id or main abbreviation of the unit
253 * @param name the full name of the unit
254 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
255 * @param unitSystem the unit system such as SI or IMPERIAL
256 */
257 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
258 {
259 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
260 }
261
262 /**
263 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
264 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
265 * @param displayAbbreviation the display abbreviation of the unit
266 * @param name the full name of the unit
267 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
268 * @param unitSystem unit system, e.g. SI or Imperial
269 */
270 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
271 final UnitSystem unitSystem)
272 {
273 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
274 }
275
276 @Override
277 public SIUnit siUnit()
278 {
279 return SI_UNIT;
280 }
281
282 @Override
283 public Unit getBaseUnit()
284 {
285 return SI;
286 }
287
288 @Override
289 public Acceleration ofSi(final double si)
290 {
291 return Acceleration.ofSi(si);
292 }
293
294 @Override
295 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
296 final double scaleFactor, final UnitSystem unitSystem)
297 {
298 if (getScale() instanceof LinearScale ls)
299 {
300 return new Acceleration.Unit(textualAbbreviation, displayAbbreviation, name,
301 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
302 }
303 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
304 }
305
306 }
307 }