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 * Force is an interaction that changes the motion of an object, measured in newtons (N).
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 Force extends Quantity<Force, Force.Unit>
22 {
23 /** Constant with value zero. */
24 public static final Force ZERO = Force.ofSi(0.0);
25
26 /** Constant with value one. */
27 public static final Force ONE = Force.ofSi(1.0);
28
29 /** Constant with value NaN. */
30 @SuppressWarnings("checkstyle:constantname")
31 public static final Force NaN = Force.ofSi(Double.NaN);
32
33 /** Constant with value POSITIVE_INFINITY. */
34 public static final Force POSITIVE_INFINITY = Force.ofSi(Double.POSITIVE_INFINITY);
35
36 /** Constant with value NEGATIVE_INFINITY. */
37 public static final Force NEGATIVE_INFINITY = Force.ofSi(Double.NEGATIVE_INFINITY);
38
39 /** Constant with value MAX_VALUE. */
40 public static final Force POS_MAXVALUE = Force.ofSi(Double.MAX_VALUE);
41
42 /** Constant with value -MAX_VALUE. */
43 public static final Force NEG_MAXVALUE = Force.ofSi(-Double.MAX_VALUE);
44
45 /** */
46 private static final long serialVersionUID = 600L;
47
48 /**
49 * Instantiate a Force 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 Force(final double value, final Force.Unit unit)
54 {
55 super(value, unit);
56 }
57
58 /**
59 * Instantiate a Force 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 Force(final double value, final String abbreviation)
64 {
65 this(value, Units.resolve(Force.Unit.class, abbreviation));
66 }
67
68 /**
69 * Construct Force quantity.
70 * @param value Scalar from which to construct this instance
71 */
72 public Force(final Force value)
73 {
74 super(value.si(), Force.Unit.SI);
75 setDisplayUnit(value.getDisplayUnit());
76 }
77
78 /**
79 * Return a Force instance based on an SI value.
80 * @param si the si value
81 * @return the Force instance based on an SI value
82 */
83 public static Force ofSi(final double si)
84 {
85 return new Force(si, Force.Unit.SI);
86 }
87
88 @Override
89 public Force instantiate(final double si)
90 {
91 return ofSi(si);
92 }
93
94 @Override
95 public SIUnit siUnit()
96 {
97 return Force.Unit.SI_UNIT;
98 }
99
100 /**
101 * Returns a Force 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 Force
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 Force valueOf(final String text)
110 {
111 return Quantity.valueOf(text, ZERO);
112 }
113
114 /**
115 * Returns a Force 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 Force of(final double value, final String unitString)
123 {
124 return Quantity.of(value, unitString, ZERO);
125 }
126
127 /**
128 * Calculate the division of Force and Force, which results in a Dimensionless quantity.
129 * @param v quantity
130 * @return quantity as a division of Force and Force
131 */
132 public final Dimensionless divide(final Force v)
133 {
134 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
135 }
136
137 /**
138 * Calculate the multiplication of Force and Length, which results in a Energy scalar.
139 * @param v scalar
140 * @return scalar as a multiplication of Force and Length
141 */
142 public final Energy multiply(final Length v)
143 {
144 return new Energy(this.si() * v.si(), Energy.Unit.SI);
145 }
146
147 /**
148 * Calculate the division of Force and LinearObjectDensity, which results in a Energy scalar.
149 * @param v scalar
150 * @return scalar as a division of Force and LinearObjectDensity
151 */
152 public final Energy divide(final LinearObjectDensity v)
153 {
154 return new Energy(this.si() / v.si(), Energy.Unit.SI);
155 }
156
157 /**
158 * Calculate the division of Force and Energy, which results in a LinearObjectDensity scalar.
159 * @param v scalar
160 * @return scalar as a division of Force and Energy
161 */
162 public final LinearObjectDensity divide(final Energy v)
163 {
164 return new LinearObjectDensity(this.si() / v.si(), LinearObjectDensity.Unit.SI);
165 }
166
167 /**
168 * Calculate the multiplication of Force and Speed, which results in a Power scalar.
169 * @param v scalar
170 * @return scalar as a multiplication of Force and Speed
171 */
172 public final Power multiply(final Speed v)
173 {
174 return new Power(this.si() * v.si(), Power.Unit.SI);
175 }
176
177 /**
178 * Calculate the division of Force and Mass, which results in a Acceleration scalar.
179 * @param v scalar
180 * @return scalar as a division of Force and Mass
181 */
182 public final Acceleration divide(final Mass v)
183 {
184 return new Acceleration(this.si() / v.si(), Acceleration.Unit.SI);
185 }
186
187 /**
188 * Calculate the division of Force and Acceleration, which results in a Mass scalar.
189 * @param v scalar
190 * @return scalar as a division of Force and Acceleration
191 */
192 public final Mass divide(final Acceleration v)
193 {
194 return new Mass(this.si() / v.si(), Mass.Unit.SI);
195 }
196
197 /**
198 * Calculate the division of Force and Area, which results in a Pressure scalar.
199 * @param v scalar
200 * @return scalar as a division of Force and Area
201 */
202 public final Pressure divide(final Area v)
203 {
204 return new Pressure(this.si() / v.si(), Pressure.Unit.SI);
205 }
206
207 /**
208 * Calculate the division of Force and Pressure, which results in a Area scalar.
209 * @param v scalar
210 * @return scalar as a division of Force and Pressure
211 */
212 public final Area divide(final Pressure v)
213 {
214 return new Area(this.si() / v.si(), Area.Unit.SI);
215 }
216
217 /******************************************************************************************************/
218 /********************************************** UNIT CLASS ********************************************/
219 /******************************************************************************************************/
220
221 /**
222 * Force.Unit encodes the units of force.
223 * <p>
224 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
225 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
226 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
227 * @author Alexander Verbraeck
228 */
229 @SuppressWarnings("checkstyle:constantname")
230 public static class Unit extends AbstractUnit<Force.Unit, Force>
231 {
232 /** The dimensions of force: kgm/s2. */
233 public static final SIUnit SI_UNIT = SIUnit.of("kgm/s2");
234
235 /** Gray. */
236 public static final Force.Unit N = new Force.Unit("N", "newton", 1.0, UnitSystem.SI_DERIVED);
237
238 /** The SI or BASE unit. */
239 public static final Force.Unit SI = N.generateSiPrefixes(false, false);
240
241 /** Dyne. */
242 public static final Force.Unit dyn = N.deriveUnit("dyn", "dyne", 1E-5, UnitSystem.CGS);
243
244 /** kilogram-force. */
245 public static final Force.Unit kgf =
246 SI.deriveUnit("kgf", "kilogram-force", Acceleration.Unit.CONST_GRAVITY, UnitSystem.OTHER);
247
248 /** ounce-force. */
249 public static final Force.Unit ozf = SI.deriveUnit("ozf", "ounce-force",
250 Mass.Unit.CONST_OUNCE * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
251
252 /** pound-force. */
253 public static final Force.Unit lbf =
254 SI.deriveUnit("lbf", "pound-force", Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
255
256 /** ton-force. */
257 public static final Force.Unit tnf = SI.deriveUnit("tnf", "ton-force",
258 Mass.Unit.CONST_TON_SHORT * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
259
260 /** sthene. */
261 public static final Force.Unit sn = SI.deriveUnit("sn", "sthene", 1000.0, UnitSystem.MTS);
262
263 /**
264 * Create a new Force unit.
265 * @param id the id or main abbreviation of the unit
266 * @param name the full name of the unit
267 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
268 * @param unitSystem the unit system such as SI or IMPERIAL
269 */
270 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
271 {
272 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
273 }
274
275 /**
276 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
277 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
278 * @param displayAbbreviation the display abbreviation of the unit
279 * @param name the full name of the unit
280 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
281 * @param unitSystem unit system, e.g. SI or Imperial
282 */
283 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
284 final UnitSystem unitSystem)
285 {
286 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
287 }
288
289 @Override
290 public SIUnit siUnit()
291 {
292 return SI_UNIT;
293 }
294
295 @Override
296 public Unit getBaseUnit()
297 {
298 return SI;
299 }
300
301 @Override
302 public Force ofSi(final double si)
303 {
304 return Force.ofSi(si);
305 }
306
307 @Override
308 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
309 final double scaleFactor, final UnitSystem unitSystem)
310 {
311 if (getScale() instanceof LinearScale ls)
312 {
313 return new Force.Unit(textualAbbreviation, displayAbbreviation, name,
314 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
315 }
316 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
317 }
318
319 }
320 }