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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.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   * Torque is a measure of rotational force about an axis, measured in newton meters (Nm).
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 Torque extends Quantity<Torque>
23  {
24      /** Constant with value zero. */
25      public static final Torque ZERO = ofSi(0.0);
26  
27      /** Constant with value one. */
28      public static final Torque ONE = ofSi(1.0);
29  
30      /** Constant with value NaN. */
31      @SuppressWarnings("checkstyle:constantname")
32      public static final Torque NaN = ofSi(Double.NaN);
33  
34      /** Constant with value POSITIVE_INFINITY. */
35      public static final Torque POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
36  
37      /** Constant with value NEGATIVE_INFINITY. */
38      public static final Torque NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
39  
40      /** Constant with value MAX_VALUE. */
41      public static final Torque POS_MAXVALUE = ofSi(Double.MAX_VALUE);
42  
43      /** Constant with value -MAX_VALUE. */
44      public static final Torque NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
45  
46      /** */
47      private static final long serialVersionUID = 600L;
48  
49      /**
50       * Instantiate a Torque 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 Torque(final double value, final Torque.Unit displayUnit, final boolean useSi)
56      {
57          super(value, displayUnit, useSi);
58      }
59  
60      /**
61       * Instantiate a Torque 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 Torque(final double valueInUnit, final Torque.Unit unit)
66      {
67          this(valueInUnit, unit, false);
68      }
69  
70      /**
71       * Return a Torque instance based on an SI value.
72       * @param si the si value
73       * @return the Torque instance based on an SI value
74       */
75      public static Torque ofSi(final double si)
76      {
77          return new Torque(si, Torque.Unit.SI, true);
78      }
79  
80      /**
81       * Instantiate a Torque 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 Torque instance based on an SI value with the given display unit
85       */
86      public static Torque ofSi(final double siValue, final Torque.Unit displayUnit)
87      {
88          return new Torque(siValue, displayUnit, true);
89      }
90  
91      @Override
92      public Torque instantiateSi(final double siValue, final UnitInterface<Torque> displayUnit)
93      {
94          return new Torque(siValue, (Torque.Unit) displayUnit, true);
95      }
96  
97      /**
98       * Returns a Torque representation of a textual representation of a value with a unit. The String representation that can be
99       * parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed,
100      * but not required, between the value and the unit.
101      * @param text the textual representation to parse into a Torque
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 Torque valueOf(final String text)
107     {
108         return Quantity.valueOf(text, ZERO);
109     }
110 
111     /**
112      * Returns a Torque 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 Torque representation of the value in its unit
116      */
117     public static Torque of(final double valueInUnit, final Torque.Unit unit)
118     {
119         return new Torque(valueInUnit, unit);
120     }
121 
122     /**
123      * Returns a Torque 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 Torque of(final double valueInUnit, final String unitString)
131     {
132         return Quantity.of(valueInUnit, unitString, ZERO);
133     }
134 
135     @Override
136     public Torque.Unit getDisplayUnit()
137     {
138         return (Torque.Unit) super.getDisplayUnit();
139     }
140 
141     /**
142      * Calculate the division of Torque and Torque, which results in a Dimensionless quantity.
143      * @param v quantity
144      * @return quantity as a division of Torque and Torque
145      */
146     public Dimensionless divide(final Torque v)
147     {
148         return new Dimensionless(this.si() / v.si(), Unitless.BASE);
149     }
150 
151     /**
152      * Calculate the division of Torque and Force, which results in a Length scalar.
153      * @param v scalar
154      * @return scalar as a division of Torque and Force
155      */
156     public Length divide(final Force v)
157     {
158         return new Length(this.si() / v.si(), Length.Unit.SI);
159     }
160 
161     /**
162      * Calculate the division of Torque and Length, which results in a Force scalar.
163      * @param v scalar
164      * @return scalar as a division of Torque and Length
165      */
166     public Force divide(final Length v)
167     {
168         return new Force(this.si() / v.si(), Force.Unit.SI);
169     }
170 
171     /**
172      * Calculate the multiplication of Torque and LinearObjectDensity, which results in a Force scalar.
173      * @param v scalar
174      * @return scalar as a multiplication of Torque and LinearObjectDensity
175      */
176     public Force multiply(final LinearObjectDensity v)
177     {
178         return new Force(this.si() * v.si(), Force.Unit.SI);
179     }
180 
181     /**
182      * Calculate the division of Torque and Duration, which results in a Power scalar.
183      * @param v scalar
184      * @return scalar as a division of Torque and Duration
185      */
186     public Power divide(final Duration v)
187     {
188         return new Power(this.si() / v.si(), Power.Unit.SI);
189     }
190 
191     /**
192      * Calculate the division of Torque and Power, which results in a Duration scalar.
193      * @param v scalar
194      * @return scalar as a division of Torque and Power
195      */
196     public Duration divide(final Power v)
197     {
198         return new Duration(this.si() / v.si(), Duration.Unit.SI);
199     }
200 
201     /**
202      * Calculate the multiplication of Torque and Frequency, which results in a Power scalar.
203      * @param v scalar
204      * @return scalar as a multiplication of Torque and Frequency
205      */
206     public Power multiply(final Frequency v)
207     {
208         return new Power(this.si() * v.si(), Power.Unit.SI);
209     }
210 
211     /**
212      * Calculate the division of Torque and Volume, which results in a Pressure scalar.
213      * @param v scalar
214      * @return scalar as a division of Torque and Volume
215      */
216     public Pressure divide(final Volume v)
217     {
218         return new Pressure(this.si() / v.si(), Pressure.Unit.SI);
219     }
220 
221     /**
222      * Calculate the division of Torque and Pressure, which results in a Volume scalar.
223      * @param v scalar
224      * @return scalar as a division of Torque and Pressure
225      */
226     public Volume divide(final Pressure v)
227     {
228         return new Volume(this.si() / v.si(), Volume.Unit.SI);
229     }
230 
231     /******************************************************************************************************/
232     /********************************************** UNIT CLASS ********************************************/
233     /******************************************************************************************************/
234 
235     /**
236      * Torque.Unit encodes the units of rotational force about an axis, measured in newton meters (Nm).
237      * <p>
238      * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
239      * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
240      * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
241      * @author Alexander Verbraeck
242      */
243     @SuppressWarnings("checkstyle:constantname")
244     public static class Unit extends AbstractUnit<Torque>
245     {
246         /** The dimensions of torque: kgm2/s2. */
247         public static final SIUnit SI_UNIT = SIUnit.of("kgm2/s2");
248 
249         /** Newton meter. */
250         public static final Torque.Unit Nm = new Torque.Unit("Nm", "newton meter", 1.0, UnitSystem.SI_DERIVED);
251 
252         /** The SI or BASE unit. */
253         public static final Torque.Unit SI = Nm;
254 
255         /** meter kilogram-force. */
256         public static final Torque.Unit m_kgf =
257                 SI.deriveUnit("m.kgf", "meter kilogram-force", Acceleration.Unit.CONST_GRAVITY, UnitSystem.OTHER);
258 
259         /** Pound foot. */
260         public static final Torque.Unit lbf_ft = SI.deriveUnit("lbf.ft", "pound-force foot",
261                 Length.Unit.CONST_FT * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
262 
263         /** Pound inch. */
264         public static final Torque.Unit lbf_in = SI.deriveUnit("lbf.in", "pound-force inch",
265                 Length.Unit.CONST_IN * Mass.Unit.CONST_LB * Acceleration.Unit.CONST_GRAVITY, UnitSystem.IMPERIAL);
266 
267         /**
268          * Create a new Torque unit.
269          * @param id the id or main abbreviation of the unit
270          * @param name the full name of the unit
271          * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
272          * @param unitSystem the unit system such as SI or IMPERIAL
273          */
274         public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
275         {
276             super(id, name, scaleFactorToBaseUnit, unitSystem);
277         }
278 
279         /**
280          * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
281          * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
282          * @param displayAbbreviation the display abbreviation of the unit
283          * @param name the full name of the unit
284          * @param scale the scale to use to convert from this unit to the standard (e.g., SI, BASE) unit
285          * @param unitSystem unit system, e.g. SI or Imperial
286          * @param siPrefix the SI Prefix of this unit
287          */
288         public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
289                 final UnitSystem unitSystem, final SIPrefix siPrefix)
290         {
291             super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem, siPrefix);
292         }
293 
294         @Override
295         public SIUnit siUnit()
296         {
297             return SI_UNIT;
298         }
299 
300         @Override
301         public Unit getBaseUnit()
302         {
303             return SI;
304         }
305 
306         @Override
307         public Torque ofSi(final double si, final UnitInterface<Torque> displayUnit)
308         {
309             return new Torque(si, (Unit) displayUnit, true);
310         }
311 
312         @Override
313         public Torque.Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
314                 final double scaleFactor, final UnitSystem unitSystem, final SIPrefix siPrefix)
315         {
316             if (getScale() instanceof LinearScale ls)
317             {
318                 return new Torque.Unit(textualAbbreviation, displayAbbreviation, name,
319                         new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem, siPrefix);
320             }
321             throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
322         }
323 
324         @Override
325         public Torque.Unit deriveUnit(final String abbreviation, final String name, final double scaleFactor,
326                 final UnitSystem unitSystem)
327         {
328             return (Unit) super.deriveUnit(abbreviation, name, scaleFactor, unitSystem);
329         }
330 
331     }
332 
333 }