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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.scale.LinearScale;
8   import org.djunits.unit.scale.Scale;
9   import org.djunits.unit.si.SIUnit;
10  import org.djunits.unit.system.UnitSystem;
11  
12  /**
13   * Torque is a measure of rotational force about an axis, measured in newton meters (Nm).
14   * <p>
15   * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
16   * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
17   * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
18   * @author Alexander Verbraeck
19   */
20  public class Torque extends Quantity<Torque>
21  {
22      /** Constant with value zero. */
23      public static final Torque ZERO = ofSi(0.0);
24  
25      /** Constant with value one. */
26      public static final Torque ONE = ofSi(1.0);
27  
28      /** Constant with value NaN. */
29      @SuppressWarnings("checkstyle:constantname")
30      public static final Torque NaN = ofSi(Double.NaN);
31  
32      /** Constant with value POSITIVE_INFINITY. */
33      public static final Torque POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
34  
35      /** Constant with value NEGATIVE_INFINITY. */
36      public static final Torque NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
37  
38      /** Constant with value MAX_VALUE. */
39      public static final Torque POS_MAXVALUE = ofSi(Double.MAX_VALUE);
40  
41      /** Constant with value -MAX_VALUE. */
42      public static final Torque NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
43  
44      /** */
45      private static final long serialVersionUID = 600L;
46  
47      /**
48       * Instantiate a Torque quantity with a unit.
49       * @param valueInUnit the value, expressed in the unit
50       * @param unit the unit in which the value is expressed
51       */
52      public Torque(final double valueInUnit, final Torque.Unit unit)
53      {
54          super(valueInUnit, unit);
55      }
56  
57      /**
58       * Return a Torque instance based on an SI value.
59       * @param si the si value
60       * @return the Torque instance based on an SI value
61       */
62      public static Torque ofSi(final double si)
63      {
64          return new Torque(si, Torque.Unit.SI);
65      }
66  
67      @Override
68      public Torque instantiateSi(final double si)
69      {
70          return ofSi(si);
71      }
72  
73      @Override
74      public SIUnit siUnit()
75      {
76          return Torque.Unit.SI_UNIT;
77      }
78  
79      /**
80       * Returns a Torque representation of a textual representation of a value with a unit. The String representation that can be
81       * parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed,
82       * but not required, between the value and the unit.
83       * @param text the textual representation to parse into a Torque
84       * @return the Scalar representation of the value in its unit
85       * @throws IllegalArgumentException when the text cannot be parsed
86       * @throws NullPointerException when the text argument is null
87       */
88      public static Torque valueOf(final String text)
89      {
90          return Quantity.valueOf(text, ZERO);
91      }
92  
93      /**
94       * Returns a Torque based on a value and the textual representation of the unit, which can be localized.
95       * @param valueInUnit the value, expressed in the unit as given by unitString
96       * @param unitString the textual representation of the unit
97       * @return the Scalar representation of the value in its unit
98       * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
99       * @throws NullPointerException when the unitString argument is null
100      */
101     public static Torque of(final double valueInUnit, final String unitString)
102     {
103         return Quantity.of(valueInUnit, unitString, ZERO);
104     }
105 
106     @Override
107     public Torque.Unit getDisplayUnit()
108     {
109         return (Torque.Unit) super.getDisplayUnit();
110     }
111 
112     /**
113      * Calculate the division of Torque and Torque, which results in a Dimensionless quantity.
114      * @param v quantity
115      * @return quantity as a division of Torque and Torque
116      */
117     public final Dimensionless divide(final Torque v)
118     {
119         return new Dimensionless(this.si() / v.si(), Unitless.BASE);
120     }
121 
122     /**
123      * Calculate the division of Torque and Force, which results in a Length scalar.
124      * @param v scalar
125      * @return scalar as a division of Torque and Force
126      */
127     public final Length divide(final Force v)
128     {
129         return new Length(this.si() / v.si(), Length.Unit.SI);
130     }
131 
132     /**
133      * Calculate the division of Torque and Length, which results in a Force scalar.
134      * @param v scalar
135      * @return scalar as a division of Torque and Length
136      */
137     public final Force divide(final Length v)
138     {
139         return new Force(this.si() / v.si(), Force.Unit.SI);
140     }
141 
142     /**
143      * Calculate the multiplication of Torque and LinearObjectDensity, which results in a Force scalar.
144      * @param v scalar
145      * @return scalar as a multiplication of Torque and LinearObjectDensity
146      */
147     public final Force multiply(final LinearObjectDensity v)
148     {
149         return new Force(this.si() * v.si(), Force.Unit.SI);
150     }
151 
152     /**
153      * Calculate the division of Torque and Duration, which results in a Power scalar.
154      * @param v scalar
155      * @return scalar as a division of Torque and Duration
156      */
157     public final Power divide(final Duration v)
158     {
159         return new Power(this.si() / v.si(), Power.Unit.SI);
160     }
161 
162     /**
163      * Calculate the division of Torque and Power, which results in a Duration scalar.
164      * @param v scalar
165      * @return scalar as a division of Torque and Power
166      */
167     public final Duration divide(final Power v)
168     {
169         return new Duration(this.si() / v.si(), Duration.Unit.SI);
170     }
171 
172     /**
173      * Calculate the multiplication of Torque and Frequency, which results in a Power scalar.
174      * @param v scalar
175      * @return scalar as a multiplication of Torque and Frequency
176      */
177     public final Power multiply(final Frequency v)
178     {
179         return new Power(this.si() * v.si(), Power.Unit.SI);
180     }
181 
182     /**
183      * Calculate the division of Torque and Volume, which results in a Pressure scalar.
184      * @param v scalar
185      * @return scalar as a division of Torque and Volume
186      */
187     public final Pressure divide(final Volume v)
188     {
189         return new Pressure(this.si() / v.si(), Pressure.Unit.SI);
190     }
191 
192     /**
193      * Calculate the division of Torque and Pressure, which results in a Volume scalar.
194      * @param v scalar
195      * @return scalar as a division of Torque and Pressure
196      */
197     public final Volume divide(final Pressure v)
198     {
199         return new Volume(this.si() / v.si(), Volume.Unit.SI);
200     }
201 
202     /******************************************************************************************************/
203     /********************************************** UNIT CLASS ********************************************/
204     /******************************************************************************************************/
205 
206     /**
207      * Torque.Unit encodes the units of rotational force about an axis, measured in newton meters (Nm).
208      * <p>
209      * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
210      * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
211      * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
212      * @author Alexander Verbraeck
213      */
214     @SuppressWarnings("checkstyle:constantname")
215     public static class Unit extends AbstractUnit<Torque.Unit, Torque>
216     {
217         /** The dimensions of torque: kgm2/s2. */
218         public static final SIUnit SI_UNIT = SIUnit.of("kgm2/s2");
219 
220         /** Newton meter. */
221         public static final Torque.Unit Nm = new Torque.Unit("Nm", "newton meter", 1.0, UnitSystem.SI_DERIVED);
222 
223         /** The SI or BASE unit. */
224         public static final Torque.Unit SI = Nm;
225 
226         /** meter kilogram-force. */
227         public static final Torque.Unit m_kgf =
228                 SI.deriveUnit("m.kgf", "meter kilogram-force", Acceleration.Unit.CONST_GRAVITY, UnitSystem.OTHER);
229 
230         /** Pound foot. */
231         public static final Torque.Unit lbf_ft = SI.deriveUnit("lbf.ft", "pound-force foot",
232                 Length.Unit.CONST_FT * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
233 
234         /** Pound inch. */
235         public static final Torque.Unit lbf_in = SI.deriveUnit("lbf.in", "pound-force inch",
236                 Length.Unit.CONST_IN * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
237 
238         /**
239          * Create a new Torque unit.
240          * @param id the id or main abbreviation of the unit
241          * @param name the full name of the unit
242          * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
243          * @param unitSystem the unit system such as SI or IMPERIAL
244          */
245         public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
246         {
247             super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
248         }
249 
250         /**
251          * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
252          * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
253          * @param displayAbbreviation the display abbreviation of the unit
254          * @param name the full name of the unit
255          * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
256          * @param unitSystem unit system, e.g. SI or Imperial
257          */
258         public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
259                 final UnitSystem unitSystem)
260         {
261             super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
262         }
263 
264         @Override
265         public SIUnit siUnit()
266         {
267             return SI_UNIT;
268         }
269 
270         @Override
271         public Unit getBaseUnit()
272         {
273             return SI;
274         }
275 
276         @Override
277         public Torque ofSi(final double si)
278         {
279             return Torque.ofSi(si);
280         }
281 
282         @Override
283         public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
284                 final double scaleFactor, final UnitSystem unitSystem)
285         {
286             if (getScale() instanceof LinearScale ls)
287             {
288                 return new Torque.Unit(textualAbbreviation, displayAbbreviation, name,
289                         new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
290             }
291             throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
292         }
293 
294     }
295 }