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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   * Angular velocity is the rate of rotation around an axis, measured in radians per second (rad/s).
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 AngularVelocity extends Quantity<AngularVelocity>
21  {
22      /** Constant with value zero. */
23      public static final AngularVelocity ZERO = ofSi(0.0);
24  
25      /** Constant with value one. */
26      public static final AngularVelocity ONE = ofSi(1.0);
27  
28      /** Constant with value NaN. */
29      @SuppressWarnings("checkstyle:constantname")
30      public static final AngularVelocity NaN = ofSi(Double.NaN);
31  
32      /** Constant with value POSITIVE_INFINITY. */
33      public static final AngularVelocity POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
34  
35      /** Constant with value NEGATIVE_INFINITY. */
36      public static final AngularVelocity NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
37  
38      /** Constant with value MAX_VALUE. */
39      public static final AngularVelocity POS_MAXVALUE = ofSi(Double.MAX_VALUE);
40  
41      /** Constant with value -MAX_VALUE. */
42      public static final AngularVelocity NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
43  
44      /** */
45      private static final long serialVersionUID = 600L;
46  
47      /**
48       * Instantiate a AngularVelocity 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 AngularVelocity(final double valueInUnit, final AngularVelocity.Unit unit)
53      {
54          super(valueInUnit, unit);
55      }
56  
57      /**
58       * Return a AngularVelocity instance based on an SI value.
59       * @param si the si value
60       * @return the AngularVelocity instance based on an SI value
61       */
62      public static AngularVelocity ofSi(final double si)
63      {
64          return new AngularVelocity(si, AngularVelocity.Unit.SI);
65      }
66  
67      @Override
68      public AngularVelocity instantiateSi(final double si)
69      {
70          return ofSi(si);
71      }
72  
73      @Override
74      public SIUnit siUnit()
75      {
76          return AngularVelocity.Unit.SI_UNIT;
77      }
78  
79      /**
80       * Returns a AngularVelocity representation of a textual representation of a value with a unit. The String representation
81       * that can be parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces
82       * are allowed, but not required, between the value and the unit.
83       * @param text the textual representation to parse into a AngularVelocity
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 AngularVelocity valueOf(final String text)
89      {
90          return Quantity.valueOf(text, ZERO);
91      }
92  
93      /**
94       * Returns a AngularVelocity 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 AngularVelocity of(final double valueInUnit, final String unitString)
102     {
103         return Quantity.of(valueInUnit, unitString, ZERO);
104     }
105 
106     @Override
107     public AngularVelocity.Unit getDisplayUnit()
108     {
109         return (AngularVelocity.Unit) super.getDisplayUnit();
110     }
111 
112     /**
113      * Calculate the division of AngularVelocity and AngularVelocity, which results in a Dimensionless scalar.
114      * @param v scalar
115      * @return scalar as a division of AngularVelocity and AngularVelocity
116      */
117     public final Dimensionless divide(final AngularVelocity v)
118     {
119         return new Dimensionless(this.si() / v.si(), Unitless.BASE);
120     }
121 
122     /******************************************************************************************************/
123     /********************************************** UNIT CLASS ********************************************/
124     /******************************************************************************************************/
125 
126     /**
127      * AngularVelocity.Unit encodes the units of angle (radians, degrees).
128      * <p>
129      * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
130      * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
131      * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
132      * @author Alexander Verbraeck
133      */
134     @SuppressWarnings("checkstyle:constantname")
135     public static class Unit extends AbstractUnit<AngularVelocity.Unit, AngularVelocity>
136     {
137         /** The dimensions of AngularVelocity: rad/s. */
138         public static final SIUnit SI_UNIT = SIUnit.of("rad/s");
139 
140         /** radian per second. */
141         public static final AngularVelocity.Unit rad_s =
142                 new AngularVelocity.Unit("rad/s", "radians per second", 1.0, UnitSystem.SI_DERIVED);
143 
144         /** The SI or BASE unit. */
145         public static final AngularVelocity.Unit SI = rad_s;
146 
147         /** degree per second. */
148         public static final AngularVelocity.Unit deg_s =
149                 rad_s.deriveUnit("deg/s", "\u00b0/s", "degree per second", Math.PI / 180.0, UnitSystem.SI_ACCEPTED);
150 
151         /** arcminute per second. */
152         public static final AngularVelocity.Unit arcmin_s =
153                 deg_s.deriveUnit("arcmin/s", "'/s", "arcminute per second", 1.0 / 60.0, UnitSystem.OTHER);
154 
155         /** arcsecond per second. */
156         public static final AngularVelocity.Unit arcsec_s =
157                 deg_s.deriveUnit("arcsec/s", "\"/s", "arcsecond per second", 1.0 / 3600.0, UnitSystem.OTHER);
158 
159         /** grad per second. */
160         public static final AngularVelocity.Unit grad_s =
161                 rad_s.deriveUnit("grad/s", "gradian per second", 2.0 * Math.PI / 400.0, UnitSystem.OTHER);
162 
163         /** centesimal arcminute per second. */
164         public static final AngularVelocity.Unit cdm_s =
165                 grad_s.deriveUnit("cdm/s", "c'/s", "centesimal arcminute per second", 1.0 / 100.0, UnitSystem.OTHER);
166 
167         /** centesimal arcsecond per second. */
168         public static final AngularVelocity.Unit cds_s =
169                 grad_s.deriveUnit("cds/s", "c\"/s", "centesimal arcsecond per second", 1.0 / 10000.0, UnitSystem.OTHER);
170 
171         /**
172          * Create a new AngularVelocity unit.
173          * @param id the id or main abbreviation of the unit
174          * @param name the full name of the unit
175          * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
176          * @param unitSystem the unit system such as SI or IMPERIAL
177          */
178         public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
179         {
180             super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
181         }
182 
183         /**
184          * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
185          * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
186          * @param displayAbbreviation the display abbreviation of the unit
187          * @param name the full name of the unit
188          * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
189          * @param unitSystem unit system, e.g. SI or Imperial
190          */
191         public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
192                 final UnitSystem unitSystem)
193         {
194             super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
195         }
196 
197         @Override
198         public SIUnit siUnit()
199         {
200             return SI_UNIT;
201         }
202 
203         @Override
204         public Unit getBaseUnit()
205         {
206             return SI;
207         }
208 
209         /** {@inheritDoc} */
210         @Override
211         public AngularVelocity ofSi(final double si)
212         {
213             return AngularVelocity.ofSi(si);
214         }
215 
216         @Override
217         public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
218                 final double scaleFactor, final UnitSystem unitSystem)
219         {
220             if (getScale() instanceof LinearScale ls)
221             {
222                 return new AngularVelocity.Unit(textualAbbreviation, displayAbbreviation, name,
223                         new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
224             }
225             throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
226         }
227 
228     }
229 }