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.Units;
9 import org.djunits.unit.scale.IdentityScale;
10 import org.djunits.unit.scale.LinearScale;
11 import org.djunits.unit.scale.Scale;
12 import org.djunits.unit.si.SIPrefix;
13 import org.djunits.unit.si.SIPrefixes;
14 import org.djunits.unit.si.SIUnit;
15 import org.djunits.unit.system.UnitSystem;
16
17 /**
18 * Power is the rate of energy transfer or work done per unit time, measured in watts (W).
19 * <p>
20 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
21 * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
22 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
23 * @author Alexander Verbraeck
24 */
25 public class Power extends Quantity<Power>
26 {
27 /** Constant with value zero. */
28 public static final Power ZERO = ofSi(0.0);
29
30 /** Constant with value one. */
31 public static final Power ONE = ofSi(1.0);
32
33 /** Constant with value NaN. */
34 @SuppressWarnings("checkstyle:constantname")
35 public static final Power NaN = ofSi(Double.NaN);
36
37 /** Constant with value POSITIVE_INFINITY. */
38 public static final Power POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
39
40 /** Constant with value NEGATIVE_INFINITY. */
41 public static final Power NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
42
43 /** Constant with value MAX_VALUE. */
44 public static final Power POS_MAXVALUE = ofSi(Double.MAX_VALUE);
45
46 /** Constant with value -MAX_VALUE. */
47 public static final Power NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
48
49 /** */
50 private static final long serialVersionUID = 600L;
51
52 /**
53 * Instantiate a Power quantity with an SI or base value and a display unit.
54 * @param value the quantity value expressed in the SI or base unit
55 * @param displayUnit the display unit to use
56 * @param useSi use SI value when true, use value in unit when false
57 */
58 public Power(final double value, final Power.Unit displayUnit, final boolean useSi)
59 {
60 super(value, displayUnit, useSi);
61 }
62
63 /**
64 * Instantiate a Power quantity expressed in the given unit.
65 * @param valueInUnit the quantity value expressed in the given unit
66 * @param unit the unit of the value, also acts as the display unit
67 */
68 public Power(final double valueInUnit, final Power.Unit unit)
69 {
70 this(valueInUnit, unit, false);
71 }
72
73 /**
74 * Return a Power instance based on an SI value.
75 * @param si the si value
76 * @return the Power instance based on an SI value
77 */
78 public static Power ofSi(final double si)
79 {
80 return new Power(si, Power.Unit.SI, true);
81 }
82
83 /**
84 * Instantiate a Power quantity with an SI or base value and a display unit.
85 * @param siValue the quantity value expressed in the SI or base unit
86 * @param displayUnit the display unit to use
87 * @return the Power instance based on an SI value with the given display unit
88 */
89 public static Power ofSi(final double siValue, final Power.Unit displayUnit)
90 {
91 return new Power(siValue, displayUnit, true);
92 }
93
94 @Override
95 public Power instantiateSi(final double siValue, final UnitInterface<Power> displayUnit)
96 {
97 return new Power(siValue, (Power.Unit) displayUnit, true);
98 }
99
100 /**
101 * Returns a Power representation of a textual representation of a value with a unit. The String representation that can be
102 * parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed,
103 * but not required, between the value and the unit.
104 * @param text the textual representation to parse into a Power
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 Power valueOf(final String text)
110 {
111 return Quantity.valueOf(text, ZERO);
112 }
113
114 /**
115 * Returns a Power based on a value expressed in the unit.
116 * @param valueInUnit the value, expressed in the given unit
117 * @param unit the unit of the value, also acts as the display unit
118 * @return ab Power representation of the value in its unit
119 */
120 public static Power of(final double valueInUnit, final Power.Unit unit)
121 {
122 return new Power(valueInUnit, unit);
123 }
124
125 /**
126 * Returns a Power based on a value and the textual representation of the unit, which can be localized.
127 * @param valueInUnit the value, expressed in the unit as given by unitString
128 * @param unitString the textual representation of the unit
129 * @return the Scalar representation of the value in its unit
130 * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
131 * @throws NullPointerException when the unitString argument is null
132 */
133 public static Power of(final double valueInUnit, final String unitString)
134 {
135 return Quantity.of(valueInUnit, unitString, ZERO);
136 }
137
138 @Override
139 public Power.Unit getDisplayUnit()
140 {
141 return (Power.Unit) super.getDisplayUnit();
142 }
143
144 /**
145 * Calculate the division of Power and Power, which results in a Dimensionless quantity.
146 * @param v quantity
147 * @return quantity as a division of Power and Power
148 */
149 public Dimensionless divide(final Power v)
150 {
151 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
152 }
153
154 /**
155 * Calculate the multiplication of Power and Duration, which results in a Energy scalar.
156 * @param v scalar
157 * @return scalar as a multiplication of Power and Duration
158 */
159 public Energy multiply(final Duration v)
160 {
161 return new Energy(this.si() * v.si(), Energy.Unit.SI);
162 }
163
164 /**
165 * Calculate the division of Power and Frequency, which results in a Energy scalar.
166 * @param v scalar
167 * @return scalar as a division of Power and Frequency
168 */
169 public Energy divide(final Frequency v)
170 {
171 return new Energy(this.si() / v.si(), Energy.Unit.SI);
172 }
173
174 /**
175 * Calculate the division of Power and Energy, which results in a Frequency scalar.
176 * @param v scalar
177 * @return scalar as a division of Power and Energy
178 */
179 public Frequency divide(final Energy v)
180 {
181 return new Frequency(this.si() / v.si(), Frequency.Unit.SI);
182 }
183
184 /**
185 * Calculate the division of Power and Speed, which results in a Force scalar.
186 * @param v scalar
187 * @return scalar as a division of Power and Speed
188 */
189 public Force divide(final Speed v)
190 {
191 return new Force(this.si() / v.si(), Force.Unit.SI);
192 }
193
194 /**
195 * Calculate the division of Power and Force, which results in a Speed scalar.
196 * @param v scalar
197 * @return scalar as a division of Power and Force
198 */
199 public Speed divide(final Force v)
200 {
201 return new Speed(this.si() / v.si(), Speed.Unit.SI);
202 }
203
204 /**
205 * Calculate the division of Power and ElectricPotential, which results in a ElectricCurrent scalar.
206 * @param v scalar
207 * @return scalar as a division of Power and ElectricPotential
208 */
209 public ElectricCurrent divide(final ElectricPotential v)
210 {
211 return new ElectricCurrent(this.si() / v.si(), ElectricCurrent.Unit.SI);
212 }
213
214 /**
215 * Calculate the division of Power and ElectricCurrent, which results in a ElectricPotential scalar.
216 * @param v scalar
217 * @return scalar as a division of Power and ElectricCurrent
218 */
219 public ElectricPotential divide(final ElectricCurrent v)
220 {
221 return new ElectricPotential(this.si() / v.si(), ElectricPotential.Unit.SI);
222 }
223
224 /**
225 * Calculate the division of Power and Acceleration, which results in a Momentum scalar.
226 * @param v scalar
227 * @return scalar as a division of Power and Acceleration
228 */
229 public Momentum divide(final Acceleration v)
230 {
231 return new Momentum(this.si() / v.si(), Momentum.Unit.SI);
232 }
233
234 /**
235 * Calculate the division of Power and Momentum, which results in a Acceleration scalar.
236 * @param v scalar
237 * @return scalar as a division of Power and Momentum
238 */
239 public Acceleration divide(final Momentum v)
240 {
241 return new Acceleration(this.si() / v.si(), Acceleration.Unit.SI);
242 }
243
244 /******************************************************************************************************/
245 /********************************************** UNIT CLASS ********************************************/
246 /******************************************************************************************************/
247
248 /**
249 * Power.Unit encodes the units for the rate of energy transfer or work done per unit time.
250 * <p>
251 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
252 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
253 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
254 * @author Alexander Verbraeck
255 */
256 @SuppressWarnings("checkstyle:constantname")
257 public static class Unit extends AbstractUnit<Power>
258 {
259 /** The dimensions of power: kgm2/s3. */
260 public static final SIUnit SI_UNIT = SIUnit.of("kgm2/s3");
261
262 /** Watt. */
263 public static final Power.Unit W =
264 new Power.Unit("W", "W", "watt", IdentityScale.SCALE, UnitSystem.SI_DERIVED, SIPrefixes.getSiPrefix(""));
265
266 /** The SI or BASE unit. */
267 public static final Power.Unit SI = (Unit) W.generateSiPrefixes(false, false);
268
269 /** microwatt. */
270 public static final Power.Unit muW = Units.resolve(Power.Unit.class, "muW");
271
272 /** milliwatt. */
273 public static final Power.Unit mW = Units.resolve(Power.Unit.class, "mW");
274
275 /** kilowatt. */
276 public static final Power.Unit kW = Units.resolve(Power.Unit.class, "kW");
277
278 /** megawatt. */
279 public static final Power.Unit MW = Units.resolve(Power.Unit.class, "MW");
280
281 /** gigawatt. */
282 public static final Power.Unit GW = Units.resolve(Power.Unit.class, "GW");
283
284 /** terawatt. */
285 public static final Power.Unit TW = Units.resolve(Power.Unit.class, "TW");
286
287 /** petawatt. */
288 public static final Power.Unit PW = Units.resolve(Power.Unit.class, "PW");
289
290 /** foot-pound-force per hour. */
291 public static final Power.Unit ft_lbf_h = SI.deriveUnit("ft.lbf/h", "foot pound-force per hour",
292 Length.Unit.CONST_FT * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY / 3600.0, UnitSystem.IMPERIAL);
293
294 /** foot-pound-force per minute. */
295 public static final Power.Unit ft_lbf_min = SI.deriveUnit("ft.lbf/min", "foot pound-force per minute",
296 Length.Unit.CONST_FT * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY / 60.0, UnitSystem.IMPERIAL);
297
298 /** foot-pound-force per second. */
299 public static final Power.Unit ft_lbf_s = SI.deriveUnit("ft.lbf/s", "foot pound-force per second",
300 Length.Unit.CONST_FT * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
301
302 /** horsepower (metric). */
303 public static final Power.Unit hp_M = W.deriveUnit("hp(M)", "horsepower (metric)", 735.49875, UnitSystem.OTHER);
304
305 /** sthene-meter per second. */
306 public static final Power.Unit sn_m_s = SI.deriveUnit("sn.m/s", "sthene meter per second", 1000.0, UnitSystem.MTS);
307
308 /** erg per second. */
309 public static final Power.Unit erg_s = SI.deriveUnit("erg/s", "erg per second", 1.0E-7, UnitSystem.CGS);
310
311 /**
312 * Create a new Power unit.
313 * @param id the id or main abbreviation of the unit
314 * @param name the full name of the unit
315 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
316 * @param unitSystem the unit system such as SI or IMPERIAL
317 */
318 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
319 {
320 super(id, name, scaleFactorToBaseUnit, unitSystem);
321 }
322
323 /**
324 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
325 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
326 * @param displayAbbreviation the display abbreviation of the unit
327 * @param name the full name of the unit
328 * @param scale the scale to use to convert from this unit to the standard (e.g., SI, BASE) unit
329 * @param unitSystem unit system, e.g. SI or Imperial
330 * @param siPrefix the SI Prefix of this unit
331 */
332 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
333 final UnitSystem unitSystem, final SIPrefix siPrefix)
334 {
335 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem, siPrefix);
336 }
337
338 @Override
339 public SIUnit siUnit()
340 {
341 return SI_UNIT;
342 }
343
344 @Override
345 public Unit getBaseUnit()
346 {
347 return SI;
348 }
349
350 @Override
351 public Power ofSi(final double si, final UnitInterface<Power> displayUnit)
352 {
353 return new Power(si, (Unit) displayUnit, true);
354 }
355
356 @Override
357 public Power.Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
358 final double scaleFactor, final UnitSystem unitSystem, final SIPrefix siPrefix)
359 {
360 if (getScale() instanceof LinearScale ls)
361 {
362 return new Power.Unit(textualAbbreviation, displayAbbreviation, name,
363 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem, siPrefix);
364 }
365 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
366 }
367
368 @Override
369 public Power.Unit deriveUnit(final String abbreviation, final String name, final double scaleFactor,
370 final UnitSystem unitSystem)
371 {
372 return (Unit) super.deriveUnit(abbreviation, name, scaleFactor, unitSystem);
373 }
374
375 }
376
377 }