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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   * Angular velocity is the rate of rotation around an axis, measured in radians per second (rad/s).
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 AngularVelocity extends Quantity<AngularVelocity, AngularVelocity.Unit>
22  {
23      /** Constant with value zero. */
24      public static final AngularVelocity ZERO = AngularVelocity.ofSi(0.0);
25  
26      /** Constant with value one. */
27      public static final AngularVelocity ONE = AngularVelocity.ofSi(1.0);
28  
29      /** Constant with value NaN. */
30      @SuppressWarnings("checkstyle:constantname")
31      public static final AngularVelocity NaN = AngularVelocity.ofSi(Double.NaN);
32  
33      /** Constant with value POSITIVE_INFINITY. */
34      public static final AngularVelocity POSITIVE_INFINITY = AngularVelocity.ofSi(Double.POSITIVE_INFINITY);
35  
36      /** Constant with value NEGATIVE_INFINITY. */
37      public static final AngularVelocity NEGATIVE_INFINITY = AngularVelocity.ofSi(Double.NEGATIVE_INFINITY);
38  
39      /** Constant with value MAX_VALUE. */
40      public static final AngularVelocity POS_MAXVALUE = AngularVelocity.ofSi(Double.MAX_VALUE);
41  
42      /** Constant with value -MAX_VALUE. */
43      public static final AngularVelocity NEG_MAXVALUE = AngularVelocity.ofSi(-Double.MAX_VALUE);
44  
45      /** */
46      private static final long serialVersionUID = 600L;
47  
48      /**
49       * Instantiate a AngularVelocity 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 AngularVelocity(final double value, final AngularVelocity.Unit unit)
54      {
55          super(value, unit);
56      }
57  
58      /**
59       * Instantiate a AngularVelocity 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 AngularVelocity(final double value, final String abbreviation)
64      {
65          this(value, Units.resolve(AngularVelocity.Unit.class, abbreviation));
66      }
67  
68      /**
69       * Construct AngularVelocity quantity.
70       * @param value Scalar from which to construct this instance
71       */
72      public AngularVelocity(final AngularVelocity value)
73      {
74          super(value.si(), AngularVelocity.Unit.SI);
75          setDisplayUnit(value.getDisplayUnit());
76      }
77  
78      /**
79       * Return a AngularVelocity instance based on an SI value.
80       * @param si the si value
81       * @return the AngularVelocity instance based on an SI value
82       */
83      public static AngularVelocity ofSi(final double si)
84      {
85          return new AngularVelocity(si, AngularVelocity.Unit.SI);
86      }
87  
88      @Override
89      public AngularVelocity instantiate(final double si)
90      {
91          return ofSi(si);
92      }
93  
94      @Override
95      public SIUnit siUnit()
96      {
97          return AngularVelocity.Unit.SI_UNIT;
98      }
99  
100     /**
101      * Returns a AngularVelocity representation of a textual representation of a value with a unit. The String representation
102      * that can be parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces
103      * are allowed, but not required, between the value and the unit.
104      * @param text the textual representation to parse into a AngularVelocity
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 AngularVelocity valueOf(final String text)
110     {
111         return Quantity.valueOf(text, ZERO);
112     }
113 
114     /**
115      * Returns a AngularVelocity 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 AngularVelocity of(final double value, final String unitString)
123     {
124         return Quantity.of(value, unitString, ZERO);
125     }
126 
127     /**
128      * Calculate the division of AngularVelocity and AngularVelocity, which results in a Dimensionless scalar.
129      * @param v scalar
130      * @return scalar as a division of AngularVelocity and AngularVelocity
131      */
132     public final Dimensionless divide(final AngularVelocity v)
133     {
134         return new Dimensionless(this.si() / v.si(), Unitless.BASE);
135     }
136 
137     /******************************************************************************************************/
138     /********************************************** UNIT CLASS ********************************************/
139     /******************************************************************************************************/
140 
141     /**
142      * AngularVelocity.Unit encodes the units of angle (radians, degrees).
143      * <p>
144      * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
145      * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
146      * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
147      * @author Alexander Verbraeck
148      */
149     @SuppressWarnings("checkstyle:constantname")
150     public static class Unit extends AbstractUnit<AngularVelocity.Unit, AngularVelocity>
151     {
152         /** The dimensions of AngularVelocity: rad/s. */
153         public static final SIUnit SI_UNIT = SIUnit.of("rad/s");
154 
155         /** radian per second. */
156         public static final AngularVelocity.Unit rad_s =
157                 new AngularVelocity.Unit("rad/s", "radians per second", 1.0, UnitSystem.SI_DERIVED);
158 
159         /** The SI or BASE unit. */
160         public static final AngularVelocity.Unit SI = rad_s;
161 
162         /** degree per second. */
163         public static final AngularVelocity.Unit deg_s =
164                 rad_s.deriveUnit("deg/s", "\u00b0/s", "degree per second", Math.PI / 180.0, UnitSystem.SI_ACCEPTED);
165 
166         /** arcminute per second. */
167         public static final AngularVelocity.Unit arcmin_s =
168                 deg_s.deriveUnit("arcmin/s", "'/s", "arcminute per second", 1.0 / 60.0, UnitSystem.OTHER);
169 
170         /** arcsecond per second. */
171         public static final AngularVelocity.Unit arcsec_s =
172                 deg_s.deriveUnit("arcsec/s", "\"/s", "arcsecond per second", 1.0 / 3600.0, UnitSystem.OTHER);
173 
174         /** grad per second. */
175         public static final AngularVelocity.Unit grad_s =
176                 rad_s.deriveUnit("grad/s", "gradian per second", 2.0 * Math.PI / 400.0, UnitSystem.OTHER);
177 
178         /** centesimal arcminute per second. */
179         public static final AngularVelocity.Unit cdm_s =
180                 grad_s.deriveUnit("cdm/s", "c'/s", "centesimal arcminute per second", 1.0 / 100.0, UnitSystem.OTHER);
181 
182         /** centesimal arcsecond per second. */
183         public static final AngularVelocity.Unit cds_s =
184                 grad_s.deriveUnit("cds/s", "c\"/s", "centesimal arcsecond per second", 1.0 / 10000.0, UnitSystem.OTHER);
185 
186         /**
187          * Create a new AngularVelocity unit.
188          * @param id the id or main abbreviation of the unit
189          * @param name the full name of the unit
190          * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
191          * @param unitSystem the unit system such as SI or IMPERIAL
192          */
193         public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
194         {
195             super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
196         }
197 
198         /**
199          * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
200          * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
201          * @param displayAbbreviation the display abbreviation of the unit
202          * @param name the full name of the unit
203          * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
204          * @param unitSystem unit system, e.g. SI or Imperial
205          */
206         public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
207                 final UnitSystem unitSystem)
208         {
209             super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
210         }
211 
212         @Override
213         public SIUnit siUnit()
214         {
215             return SI_UNIT;
216         }
217 
218         @Override
219         public Unit getBaseUnit()
220         {
221             return SI;
222         }
223 
224         /** {@inheritDoc} */
225         @Override
226         public AngularVelocity ofSi(final double si)
227         {
228             return AngularVelocity.ofSi(si);
229         }
230 
231         @Override
232         public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
233                 final double scaleFactor, final UnitSystem unitSystem)
234         {
235             if (getScale() instanceof LinearScale ls)
236             {
237                 return new AngularVelocity.Unit(textualAbbreviation, displayAbbreviation, name,
238                         new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
239             }
240             throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
241         }
242 
243     }
244 }