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 acceleration is the rate of change of angular velocity over time, measured in radians per second squared (rad/s2).
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 AngularAcceleration extends Quantity<AngularAcceleration, AngularAcceleration.Unit>
22 {
23 /** Constant with value zero. */
24 public static final AngularAcceleration ZERO = AngularAcceleration.ofSi(0.0);
25
26 /** Constant with value one. */
27 public static final AngularAcceleration ONE = AngularAcceleration.ofSi(1.0);
28
29 /** Constant with value NaN. */
30 @SuppressWarnings("checkstyle:constantname")
31 public static final AngularAcceleration NaN = AngularAcceleration.ofSi(Double.NaN);
32
33 /** Constant with value POSITIVE_INFINITY. */
34 public static final AngularAcceleration POSITIVE_INFINITY = AngularAcceleration.ofSi(Double.POSITIVE_INFINITY);
35
36 /** Constant with value NEGATIVE_INFINITY. */
37 public static final AngularAcceleration NEGATIVE_INFINITY = AngularAcceleration.ofSi(Double.NEGATIVE_INFINITY);
38
39 /** Constant with value MAX_VALUE. */
40 public static final AngularAcceleration POS_MAXVALUE = AngularAcceleration.ofSi(Double.MAX_VALUE);
41
42 /** Constant with value -MAX_VALUE. */
43 public static final AngularAcceleration NEG_MAXVALUE = AngularAcceleration.ofSi(-Double.MAX_VALUE);
44
45 /** */
46 private static final long serialVersionUID = 600L;
47
48 /**
49 * Instantiate a AngularAcceleration 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 AngularAcceleration(final double value, final AngularAcceleration.Unit unit)
54 {
55 super(value, unit);
56 }
57
58 /**
59 * Instantiate a AngularAcceleration 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 AngularAcceleration(final double value, final String abbreviation)
64 {
65 this(value, Units.resolve(AngularAcceleration.Unit.class, abbreviation));
66 }
67
68 /**
69 * Construct AngularAcceleration quantity.
70 * @param value Scalar from which to construct this instance
71 */
72 public AngularAcceleration(final AngularAcceleration value)
73 {
74 super(value.si(), AngularAcceleration.Unit.SI);
75 setDisplayUnit(value.getDisplayUnit());
76 }
77
78 /**
79 * Return a AngularAcceleration instance based on an SI value.
80 * @param si the si value
81 * @return the AngularAcceleration instance based on an SI value
82 */
83 public static AngularAcceleration ofSi(final double si)
84 {
85 return new AngularAcceleration(si, AngularAcceleration.Unit.SI);
86 }
87
88 @Override
89 public AngularAcceleration instantiate(final double si)
90 {
91 return ofSi(si);
92 }
93
94 @Override
95 public SIUnit siUnit()
96 {
97 return AngularAcceleration.Unit.SI_UNIT;
98 }
99
100 /**
101 * Returns a AngularAcceleration representation of a textual representation of a value with a unit. The String
102 * representation that can be parsed is the double value in the unit, followed by a localized or English abbreviation of the
103 * unit. Spaces are allowed, but not required, between the value and the unit.
104 * @param text the textual representation to parse into a AngularAcceleration
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 AngularAcceleration valueOf(final String text)
110 {
111 return Quantity.valueOf(text, ZERO);
112 }
113
114 /**
115 * Returns a AngularAcceleration 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 AngularAcceleration of(final double value, final String unitString)
123 {
124 return Quantity.of(value, unitString, ZERO);
125 }
126
127 /**
128 * Calculate the division of AngularAcceleration and AngularAcceleration, which results in a Dimensionless scalar.
129 * @param v scalar
130 * @return scalar as a division of AngularAcceleration and AngularAcceleration
131 */
132 public final Dimensionless divide(final AngularAcceleration v)
133 {
134 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
135 }
136
137 /**
138 * Calculate the multiplication of AngularAcceleration and Duration, which results in a AngularVelocity scalar.
139 * @param v scalar
140 * @return scalar as a multiplication of AngularAcceleration and Duration
141 */
142 public final AngularVelocity multiply(final Duration v)
143 {
144 return new AngularVelocity(this.si() * v.si(), AngularVelocity.Unit.SI);
145 }
146
147 /**
148 * Calculate the division of AngularAcceleration and Frequency, which results in a AngularVelocity scalar.
149 * @param v scalar
150 * @return scalar as a division of AngularAcceleration and Frequency
151 */
152 public final AngularVelocity divide(final Frequency v)
153 {
154 return new AngularVelocity(this.si() / v.si(), AngularVelocity.Unit.SI);
155 }
156
157 /**
158 * Calculate the division of AngularAcceleration and AngularVelocity, which results in a Frequency scalar.
159 * @param v scalar
160 * @return scalar as a division of AngularAcceleration and AngularVelocity
161 */
162 public final Frequency divide(final AngularVelocity v)
163 {
164 return new Frequency(this.si() / v.si(), Frequency.Unit.SI);
165 }
166
167 /******************************************************************************************************/
168 /********************************************** UNIT CLASS ********************************************/
169 /******************************************************************************************************/
170
171 /**
172 * AngularAcceleration.Unit encodes the units of angle (radians or degrees per second squared).
173 * <p>
174 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
175 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
176 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
177 * @author Alexander Verbraeck
178 */
179 @SuppressWarnings("checkstyle:constantname")
180 public static class Unit extends AbstractUnit<AngularAcceleration.Unit, AngularAcceleration>
181 {
182 /** The dimensions of AngularAcceleration: rad/s2. */
183 public static final SIUnit SI_UNIT = SIUnit.of("rad/s2");
184
185 /** radian per second squared. */
186 public static final AngularAcceleration.Unit rad_s2 =
187 new AngularAcceleration.Unit("rad/s2", "radians per second squared", 1.0, UnitSystem.SI_DERIVED);
188
189 /** The SI or BASE unit. */
190 public static final AngularAcceleration.Unit SI = rad_s2;
191
192 /** degree per second squared. */
193 public static final AngularAcceleration.Unit deg_s2 =
194 rad_s2.deriveUnit("deg/s2", "\u00b0/s2", "degree per second squared", Math.PI / 180.0, UnitSystem.SI_ACCEPTED);
195
196 /** arcminute per second squared. */
197 public static final AngularAcceleration.Unit arcmin_s2 =
198 deg_s2.deriveUnit("arcmin/s2", "'/s2", "arcminute per second squared", 1.0 / 60.0, UnitSystem.OTHER);
199
200 /** arcsecond per second squared. */
201 public static final AngularAcceleration.Unit arcsec_s2 =
202 deg_s2.deriveUnit("arcsec/s2", "\"/s2", "arcsecond per second squared", 1.0 / 3600.0, UnitSystem.OTHER);
203
204 /** grad per second squared. */
205 public static final AngularAcceleration.Unit grad_s2 =
206 rad_s2.deriveUnit("grad/s2", "gradian per second squared", 2.0 * Math.PI / 400.0, UnitSystem.OTHER);
207
208 /** centesimal arcminute per second squared. */
209 public static final AngularAcceleration.Unit cdm_s2 =
210 grad_s2.deriveUnit("cdm/s2", "c'/s2", "centesimal arcminute per second squared", 1.0 / 100.0, UnitSystem.OTHER);
211
212 /** centesimal arcsecond per second squared. */
213 public static final AngularAcceleration.Unit cds_s2 = grad_s2.deriveUnit("cds/s2", "c\"/s2",
214 "centesimal arcsecond per second squared", 1.0 / 10000.0, UnitSystem.OTHER);
215
216 /**
217 * Create a new AngularAcceleration unit.
218 * @param id the id or main abbreviation of the unit
219 * @param name the full name of the unit
220 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
221 * @param unitSystem the unit system such as SI or IMPERIAL
222 */
223 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
224 {
225 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
226 }
227
228 /**
229 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
230 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
231 * @param displayAbbreviation the display abbreviation of the unit
232 * @param name the full name of the unit
233 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
234 * @param unitSystem unit system, e.g. SI or Imperial
235 */
236 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
237 final UnitSystem unitSystem)
238 {
239 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
240 }
241
242 @Override
243 public SIUnit siUnit()
244 {
245 return SI_UNIT;
246 }
247
248 @Override
249 public Unit getBaseUnit()
250 {
251 return SI;
252 }
253
254 /** {@inheritDoc} */
255 @Override
256 public AngularAcceleration ofSi(final double si)
257 {
258 return AngularAcceleration.ofSi(si);
259 }
260
261 @Override
262 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
263 final double scaleFactor, final UnitSystem unitSystem)
264 {
265 if (getScale() instanceof LinearScale ls)
266 {
267 return new AngularAcceleration.Unit(textualAbbreviation, displayAbbreviation, name,
268 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
269 }
270 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
271 }
272
273 }
274 }