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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   * Mass is the amount of matter in an object, measured in kilograms (kg).
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 Mass extends Quantity<Mass>
22  {
23      /** Constant with value zero. */
24      public static final Mass ZERO = ofSi(0.0);
25  
26      /** Constant with value one. */
27      public static final Mass ONE = ofSi(1.0);
28  
29      /** Constant with value NaN. */
30      @SuppressWarnings("checkstyle:constantname")
31      public static final Mass NaN = ofSi(Double.NaN);
32  
33      /** Constant with value POSITIVE_INFINITY. */
34      public static final Mass POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
35  
36      /** Constant with value NEGATIVE_INFINITY. */
37      public static final Mass NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
38  
39      /** Constant with value MAX_VALUE. */
40      public static final Mass POS_MAXVALUE = ofSi(Double.MAX_VALUE);
41  
42      /** Constant with value -MAX_VALUE. */
43      public static final Mass NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
44  
45      /** */
46      private static final long serialVersionUID = 600L;
47  
48      /**
49       * Instantiate a Mass 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 Mass(final double valueInUnit, final Mass.Unit unit)
54      {
55          super(valueInUnit, unit);
56      }
57  
58      /**
59       * Return a Mass instance based on an SI value.
60       * @param si the si value
61       * @return the Mass instance based on an SI value
62       */
63      public static Mass ofSi(final double si)
64      {
65          return new Mass(si, Mass.Unit.SI);
66      }
67  
68      @Override
69      public Mass instantiateSi(final double si)
70      {
71          return ofSi(si);
72      }
73  
74      @Override
75      public SIUnit siUnit()
76      {
77          return Mass.Unit.SI_UNIT;
78      }
79  
80      /**
81       * Returns a Mass representation of a textual representation of a value with a unit. The String representation that can be
82       * parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed,
83       * but not required, between the value and the unit.
84       * @param text the textual representation to parse into a Mass
85       * @return the Scalar representation of the value in its unit
86       * @throws IllegalArgumentException when the text cannot be parsed
87       * @throws NullPointerException when the text argument is null
88       */
89      public static Mass valueOf(final String text)
90      {
91          return Quantity.valueOf(text, ZERO);
92      }
93  
94      /**
95       * Returns a Mass based on a value and the textual representation of the unit, which can be localized.
96       * @param valueInUnit the value, expressed in the unit as given by unitString
97       * @param unitString the textual representation of the unit
98       * @return the Scalar representation of the value in its unit
99       * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
100      * @throws NullPointerException when the unitString argument is null
101      */
102     public static Mass of(final double valueInUnit, final String unitString)
103     {
104         return Quantity.of(valueInUnit, unitString, ZERO);
105     }
106 
107     @Override
108     public Mass.Unit getDisplayUnit()
109     {
110         return (Mass.Unit) super.getDisplayUnit();
111     }
112 
113     /**
114      * Calculate the division of Mass and Mass, which results in a Dimensionless quantity.
115      * @param v quantity
116      * @return quantity as a division of Mass and Mass
117      */
118     public final Dimensionless divide(final Mass v)
119     {
120         return new Dimensionless(this.si() / v.si(), Unitless.BASE);
121     }
122 
123     /**
124      * Calculate the division of Mass and FlowMass, which results in a Duration scalar.
125      * @param v scalar
126      * @return scalar as a division of Mass and FlowMass
127      */
128     public final Duration divide(final FlowMass v)
129     {
130         return new Duration(this.si() / v.si(), Duration.Unit.SI);
131     }
132 
133     /**
134      * Calculate the division of Mass and Duration, which results in a FlowMass scalar.
135      * @param v scalar
136      * @return scalar as a division of Mass and Duration
137      */
138     public final FlowMass divide(final Duration v)
139     {
140         return new FlowMass(this.si() / v.si(), FlowMass.Unit.SI);
141     }
142 
143     /**
144      * Calculate the multiplication of Mass and Acceleration, which results in a Force scalar.
145      * @param v scalar
146      * @return scalar as a multiplication of Mass and Acceleration
147      */
148     public final Force multiply(final Acceleration v)
149     {
150         return new Force(this.si() * v.si(), Force.Unit.SI);
151     }
152 
153     /**
154      * Calculate the multiplication of Mass and Frequency, which results in a FlowMass scalar.
155      * @param v scalar
156      * @return scalar as a multiplication of Mass and Frequency
157      */
158     public final FlowMass multiply(final Frequency v)
159     {
160         return new FlowMass(this.si() * v.si(), FlowMass.Unit.SI);
161     }
162 
163     /**
164      * Calculate the division of Mass and Density, which results in a Volume scalar.
165      * @param v scalar
166      * @return scalar as a division of Mass and Density
167      */
168     public final Volume divide(final Density v)
169     {
170         return new Volume(this.si() / v.si(), Volume.Unit.SI);
171     }
172 
173     /**
174      * Calculate the division of Mass and Volume, which results in a Density scalar.
175      * @param v scalar
176      * @return scalar as a division of Mass and Volume
177      */
178     public final Density divide(final Volume v)
179     {
180         return new Density(this.si() / v.si(), Density.Unit.SI);
181     }
182 
183     /**
184      * Calculate the multiplication of Mass and Speed, which results in a Momentum scalar.
185      * @param v scalar
186      * @return scalar as a multiplication of Mass and Speed
187      */
188     public final Momentum multiply(final Speed v)
189     {
190         return new Momentum(this.si() * v.si(), Momentum.Unit.SI);
191     }
192 
193     /******************************************************************************************************/
194     /********************************************** UNIT CLASS ********************************************/
195     /******************************************************************************************************/
196 
197     /**
198      * Mass.Unit encodes the unit of the amount of matter in an object.
199      * <p>
200      * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
201      * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
202      * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
203      * @author Alexander Verbraeck
204      */
205     @SuppressWarnings("checkstyle:constantname")
206     public static class Unit extends AbstractUnit<Mass.Unit, Mass>
207     {
208         /** Constant for pound (lb). */
209         public static final double CONST_LB = 0.45359237;
210 
211         /** Constant for ounce. */
212         public static final double CONST_OUNCE = CONST_LB / 16.0;
213 
214         /** Constant for short ton. */
215         public static final double CONST_TON_SHORT = 2000.0 * CONST_LB;
216 
217         /** Constant for long ton. */
218         public static final double CONST_TON_LONG = 2240.0 * CONST_LB;
219 
220         /** The dimensions of mass: kg. */
221         public static final SIUnit SI_UNIT = SIUnit.of("kg");
222 
223         /** kilogram. */
224         public static final Mass.Unit kg = new Mass.Unit("kg", "kilogram", 1.0, UnitSystem.SI_BASE);
225 
226         /** The SI or BASE unit. */
227         public static final Mass.Unit SI = kg.generateSiPrefixes(true, false);
228 
229         /** gram. */
230         public static final Mass.Unit g = Units.resolve(Mass.Unit.class, "g");
231 
232         /** microgram. */
233         public static final Mass.Unit mug = Units.resolve(Mass.Unit.class, "mug");
234 
235         /** milligram. */
236         public static final Mass.Unit mg = Units.resolve(Mass.Unit.class, "mg");
237 
238         /** pound. */
239         public static final Mass.Unit lb = kg.deriveUnit("lb", "pound", CONST_LB, UnitSystem.IMPERIAL);
240 
241         /** ounce. */
242         public static final Mass.Unit oz = kg.deriveUnit("oz", "ounce", CONST_OUNCE, UnitSystem.IMPERIAL);
243 
244         /** long ton = 2240 lb. */
245         public static final Mass.Unit long_tn = kg.deriveUnit("long tn", "long ton", CONST_TON_LONG, UnitSystem.IMPERIAL);
246 
247         /** short ton = 2000 lb. */
248         public static final Mass.Unit sh_tn = kg.deriveUnit("sh tn", "short ton", CONST_TON_SHORT, UnitSystem.US_CUSTOMARY);
249 
250         /** metric ton = 1000 kg. */
251         public static final Mass.Unit t = kg.deriveUnit("t", "metric tonne", 1000.0, UnitSystem.SI_ACCEPTED);
252 
253         /** metric ton = 1000 kg. */
254         public static final Mass.Unit t_mts = kg.deriveUnit("t(mts)", "tonne", 1000.0, UnitSystem.MTS);
255 
256         /** Dalton, according to CODATA 2018. */
257         public static final Mass.Unit Da = kg.deriveUnit("Da", "Dalton", 1.66053906660E-27, UnitSystem.SI_ACCEPTED);
258 
259         /** electronvolt = 1.782661907E-36 kg. See http://physics.nist.gov/cuu/Constants/Table/allascii.txt. */
260         public static final Mass.Unit eV = kg.deriveUnit("eV", "electronvolt", 1.782661907E-36, UnitSystem.OTHER);
261 
262         /** microelectronvolt. */
263         public static final Mass.Unit mueV = eV.deriveUnit("mueV", "\u03BCeV", "microelectronvolt", 1E-6, UnitSystem.OTHER);
264 
265         /** millielectronvolt (note, no dash between milli and electron; the SI style guide forbids spaces or hyphens). */
266         public static final Mass.Unit meV = eV.deriveUnit("meV", "millielectronvolt", 1E-3, UnitSystem.OTHER);
267 
268         /** kiloelectronvolt. */
269         public static final Mass.Unit keV = eV.deriveUnit("keV", "kiloelectronvolt", 1E3, UnitSystem.OTHER);
270 
271         /** megaelectronvolt. */
272         public static final Mass.Unit MeV = eV.deriveUnit("MeV", "megaelectronvolt", 1E6, UnitSystem.OTHER);
273 
274         /** gigaelectronvolt. */
275         public static final Mass.Unit GeV = eV.deriveUnit("GeV", "gigaelectronvolt", 1E9, UnitSystem.OTHER);
276 
277         /**
278          * Create a new Mass unit.
279          * @param id the id or main abbreviation of the unit
280          * @param name the full name of the unit
281          * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
282          * @param unitSystem the unit system such as SI or IMPERIAL
283          */
284         public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
285         {
286             super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
287         }
288 
289         /**
290          * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
291          * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
292          * @param displayAbbreviation the display abbreviation of the unit
293          * @param name the full name of the unit
294          * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
295          * @param unitSystem unit system, e.g. SI or Imperial
296          */
297         public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
298                 final UnitSystem unitSystem)
299         {
300             super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
301         }
302 
303         @Override
304         public SIUnit siUnit()
305         {
306             return SI_UNIT;
307         }
308 
309         @Override
310         public Unit getBaseUnit()
311         {
312             return SI;
313         }
314 
315         @Override
316         public Mass ofSi(final double si)
317         {
318             return Mass.ofSi(si);
319         }
320 
321         @Override
322         public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
323                 final double scaleFactor, final UnitSystem unitSystem)
324         {
325             if (getScale() instanceof LinearScale ls)
326             {
327                 return new Mass.Unit(textualAbbreviation, displayAbbreviation, name,
328                         new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
329             }
330             throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
331         }
332 
333     }
334 }