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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.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   * Torque is a measure of rotational force about an axis, measured in newton meters (Nm).
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 Torque extends Quantity<Torque>
22  {
23      /** Constant with value zero. */
24      public static final Torque ZERO = Torque.ofSi(0.0);
25  
26      /** Constant with value one. */
27      public static final Torque ONE = Torque.ofSi(1.0);
28  
29      /** Constant with value NaN. */
30      @SuppressWarnings("checkstyle:constantname")
31      public static final Torque NaN = Torque.ofSi(Double.NaN);
32  
33      /** Constant with value POSITIVE_INFINITY. */
34      public static final Torque POSITIVE_INFINITY = Torque.ofSi(Double.POSITIVE_INFINITY);
35  
36      /** Constant with value NEGATIVE_INFINITY. */
37      public static final Torque NEGATIVE_INFINITY = Torque.ofSi(Double.NEGATIVE_INFINITY);
38  
39      /** Constant with value MAX_VALUE. */
40      public static final Torque POS_MAXVALUE = Torque.ofSi(Double.MAX_VALUE);
41  
42      /** Constant with value -MAX_VALUE. */
43      public static final Torque NEG_MAXVALUE = Torque.ofSi(-Double.MAX_VALUE);
44  
45      /** */
46      private static final long serialVersionUID = 600L;
47  
48      /**
49       * Instantiate a Torque quantity with a unit.
50       * @param valueInUnit the value, expressed in the unit
51       * @param unit the unit in which the value is expressed
52       */
53      public Torque(final double valueInUnit, final Torque.Unit unit)
54      {
55          super(valueInUnit, unit);
56      }
57  
58      /**
59       * Instantiate a Torque quantity with a unit, expressed as a String.
60       * @param valueInUnit the value, expressed in the unit
61       * @param abbreviation the String abbreviation of the unit in which the value is expressed
62       */
63      public Torque(final double valueInUnit, final String abbreviation)
64      {
65          this(valueInUnit, Units.resolve(Torque.Unit.class, abbreviation));
66      }
67  
68      /**
69       * Construct Torque quantity.
70       * @param value Scalar from which to construct this instance
71       */
72      public Torque(final Torque value)
73      {
74          super(value.si(), Torque.Unit.SI);
75          setDisplayUnit(value.getDisplayUnit());
76      }
77  
78      /**
79       * Return a Torque instance based on an SI value.
80       * @param si the si value
81       * @return the Torque instance based on an SI value
82       */
83      public static Torque ofSi(final double si)
84      {
85          return new Torque(si, Torque.Unit.SI);
86      }
87  
88      @Override
89      public Torque instantiateSi(final double si)
90      {
91          return ofSi(si);
92      }
93  
94      @Override
95      public SIUnit siUnit()
96      {
97          return Torque.Unit.SI_UNIT;
98      }
99  
100     /**
101      * Returns a Torque 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 Torque
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 Torque valueOf(final String text)
110     {
111         return Quantity.valueOf(text, ZERO);
112     }
113 
114     /**
115      * Returns a Torque based on a value and the textual representation of the unit, which can be localized.
116      * @param valueInUnit the value, expressed in the unit as given by unitString
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 Torque of(final double valueInUnit, final String unitString)
123     {
124         return Quantity.of(valueInUnit, unitString, ZERO);
125     }
126 
127     @Override
128     public Torque.Unit getDisplayUnit()
129     {
130         return (Torque.Unit) super.getDisplayUnit();
131     }
132 
133     /**
134      * Calculate the division of Torque and Torque, which results in a Dimensionless quantity.
135      * @param v quantity
136      * @return quantity as a division of Torque and Torque
137      */
138     public final Dimensionless divide(final Torque v)
139     {
140         return new Dimensionless(this.si() / v.si(), Unitless.BASE);
141     }
142 
143     /**
144      * Calculate the division of Torque and Force, which results in a Length scalar.
145      * @param v scalar
146      * @return scalar as a division of Torque and Force
147      */
148     public final Length divide(final Force v)
149     {
150         return new Length(this.si() / v.si(), Length.Unit.SI);
151     }
152 
153     /**
154      * Calculate the division of Torque and Length, which results in a Force scalar.
155      * @param v scalar
156      * @return scalar as a division of Torque and Length
157      */
158     public final Force divide(final Length v)
159     {
160         return new Force(this.si() / v.si(), Force.Unit.SI);
161     }
162 
163     /**
164      * Calculate the multiplication of Torque and LinearObjectDensity, which results in a Force scalar.
165      * @param v scalar
166      * @return scalar as a multiplication of Torque and LinearObjectDensity
167      */
168     public final Force multiply(final LinearObjectDensity v)
169     {
170         return new Force(this.si() * v.si(), Force.Unit.SI);
171     }
172 
173     /**
174      * Calculate the division of Torque and Duration, which results in a Power scalar.
175      * @param v scalar
176      * @return scalar as a division of Torque and Duration
177      */
178     public final Power divide(final Duration v)
179     {
180         return new Power(this.si() / v.si(), Power.Unit.SI);
181     }
182 
183     /**
184      * Calculate the division of Torque and Power, which results in a Duration scalar.
185      * @param v scalar
186      * @return scalar as a division of Torque and Power
187      */
188     public final Duration divide(final Power v)
189     {
190         return new Duration(this.si() / v.si(), Duration.Unit.SI);
191     }
192 
193     /**
194      * Calculate the multiplication of Torque and Frequency, which results in a Power scalar.
195      * @param v scalar
196      * @return scalar as a multiplication of Torque and Frequency
197      */
198     public final Power multiply(final Frequency v)
199     {
200         return new Power(this.si() * v.si(), Power.Unit.SI);
201     }
202 
203     /**
204      * Calculate the division of Torque and Volume, which results in a Pressure scalar.
205      * @param v scalar
206      * @return scalar as a division of Torque and Volume
207      */
208     public final Pressure divide(final Volume v)
209     {
210         return new Pressure(this.si() / v.si(), Pressure.Unit.SI);
211     }
212 
213     /**
214      * Calculate the division of Torque and Pressure, which results in a Volume scalar.
215      * @param v scalar
216      * @return scalar as a division of Torque and Pressure
217      */
218     public final Volume divide(final Pressure v)
219     {
220         return new Volume(this.si() / v.si(), Volume.Unit.SI);
221     }
222 
223     /******************************************************************************************************/
224     /********************************************** UNIT CLASS ********************************************/
225     /******************************************************************************************************/
226 
227     /**
228      * Torque.Unit encodes the units of rotational force about an axis, measured in newton meters (Nm).
229      * <p>
230      * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
231      * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
232      * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
233      * @author Alexander Verbraeck
234      */
235     @SuppressWarnings("checkstyle:constantname")
236     public static class Unit extends AbstractUnit<Torque.Unit, Torque>
237     {
238         /** The dimensions of torque: kgm2/s2. */
239         public static final SIUnit SI_UNIT = SIUnit.of("kgm2/s2");
240 
241         /** Newton meter. */
242         public static final Torque.Unit Nm = new Torque.Unit("Nm", "newton meter", 1.0, UnitSystem.SI_DERIVED);
243 
244         /** The SI or BASE unit. */
245         public static final Torque.Unit SI = Nm;
246 
247         /** meter kilogram-force. */
248         public static final Torque.Unit m_kgf =
249                 SI.deriveUnit("m.kgf", "meter kilogram-force", Acceleration.Unit.CONST_GRAVITY, UnitSystem.OTHER);
250 
251         /** Pound foot. */
252         public static final Torque.Unit lbf_ft = SI.deriveUnit("lbf.ft", "pound-force foot",
253                 Length.Unit.CONST_FT * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
254 
255         /** Pound inch. */
256         public static final Torque.Unit lbf_in = SI.deriveUnit("lbf.in", "pound-force inch",
257                 Length.Unit.CONST_IN * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
258 
259         /**
260          * Create a new Torque unit.
261          * @param id the id or main abbreviation of the unit
262          * @param name the full name of the unit
263          * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
264          * @param unitSystem the unit system such as SI or IMPERIAL
265          */
266         public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
267         {
268             super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
269         }
270 
271         /**
272          * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
273          * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
274          * @param displayAbbreviation the display abbreviation of the unit
275          * @param name the full name of the unit
276          * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
277          * @param unitSystem unit system, e.g. SI or Imperial
278          */
279         public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
280                 final UnitSystem unitSystem)
281         {
282             super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
283         }
284 
285         @Override
286         public SIUnit siUnit()
287         {
288             return SI_UNIT;
289         }
290 
291         @Override
292         public Unit getBaseUnit()
293         {
294             return SI;
295         }
296 
297         @Override
298         public Torque ofSi(final double si)
299         {
300             return Torque.ofSi(si);
301         }
302 
303         @Override
304         public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
305                 final double scaleFactor, final UnitSystem unitSystem)
306         {
307             if (getScale() instanceof LinearScale ls)
308             {
309                 return new Torque.Unit(textualAbbreviation, displayAbbreviation, name,
310                         new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
311             }
312             throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
313         }
314 
315     }
316 }