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