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.IdentityScale;
9 import org.djunits.unit.scale.LinearScale;
10 import org.djunits.unit.scale.Scale;
11 import org.djunits.unit.si.SIUnit;
12 import org.djunits.unit.system.UnitSystem;
13
14 /**
15 * Electrical resistence measures the opposition to the flow of an electric current, and is expressed in ohm. Its reciprocal
16 * quantity is electrical conductance (expressed in siemens).
17 * <p>
18 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
19 * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
20 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
21 * @author Alexander Verbraeck
22 */
23 public class ElectricalResistance extends Quantity<ElectricalResistance>
24 {
25 /** Constant with value zero. */
26 public static final ElectricalResistance ZERO = ofSi(0.0);
27
28 /** Constant with value one. */
29 public static final ElectricalResistance ONE = ofSi(1.0);
30
31 /** Constant with value NaN. */
32 @SuppressWarnings("checkstyle:constantname")
33 public static final ElectricalResistance NaN = ofSi(Double.NaN);
34
35 /** Constant with value POSITIVE_INFINITY. */
36 public static final ElectricalResistance POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
37
38 /** Constant with value NEGATIVE_INFINITY. */
39 public static final ElectricalResistance NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
40
41 /** Constant with value MAX_VALUE. */
42 public static final ElectricalResistance POS_MAXVALUE = ofSi(Double.MAX_VALUE);
43
44 /** Constant with value -MAX_VALUE. */
45 public static final ElectricalResistance NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
46
47 /** */
48 private static final long serialVersionUID = 600L;
49
50 /**
51 * Instantiate a ElectricalResistance quantity with a unit.
52 * @param valueInUnit the value, expressed in the unit
53 * @param unit the unit in which the value is expressed
54 */
55 public ElectricalResistance(final double valueInUnit, final ElectricalResistance.Unit unit)
56 {
57 super(valueInUnit, unit);
58 }
59
60 /**
61 * Return a ElectricalResistance instance based on an SI value.
62 * @param si the si value
63 * @return the ElectricalResistance instance based on an SI value
64 */
65 public static ElectricalResistance ofSi(final double si)
66 {
67 return new ElectricalResistance(si, ElectricalResistance.Unit.SI);
68 }
69
70 @Override
71 public ElectricalResistance instantiateSi(final double si)
72 {
73 return ofSi(si);
74 }
75
76 @Override
77 public SIUnit siUnit()
78 {
79 return ElectricalResistance.Unit.SI_UNIT;
80 }
81
82 /**
83 * Returns a ElectricalResistance representation of a textual representation of a value with a unit. The String
84 * representation that can be parsed is the double value in the unit, followed by a localized or English abbreviation of the
85 * unit. Spaces are allowed, but not required, between the value and the unit.
86 * @param text the textual representation to parse into a ElectricalResistance
87 * @return the Scalar representation of the value in its unit
88 * @throws IllegalArgumentException when the text cannot be parsed
89 * @throws NullPointerException when the text argument is null
90 */
91 public static ElectricalResistance valueOf(final String text)
92 {
93 return Quantity.valueOf(text, ZERO);
94 }
95
96 /**
97 * Returns a ElectricalResistance based on a value and the textual representation of the unit, which can be localized.
98 * @param valueInUnit the value, expressed in the unit as given by unitString
99 * @param unitString the textual representation of the unit
100 * @return the Scalar representation of the value in its unit
101 * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
102 * @throws NullPointerException when the unitString argument is null
103 */
104 public static ElectricalResistance of(final double valueInUnit, final String unitString)
105 {
106 return Quantity.of(valueInUnit, unitString, ZERO);
107 }
108
109 @Override
110 public ElectricalResistance.Unit getDisplayUnit()
111 {
112 return (ElectricalResistance.Unit) super.getDisplayUnit();
113 }
114
115 /**
116 * Calculate the division of ElectricalResistance and ElectricalResistance, which results in a Dimensionless quantity.
117 * @param v quantity
118 * @return quantity as a division of ElectricalResistance and ElectricalResistance
119 */
120 public final Dimensionless divide(final ElectricalResistance v)
121 {
122 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
123 }
124
125 /**
126 * Calculate the multiplication of ElectricalResistance and ElectricalConductance, which results in a Dimensionless scalar.
127 * @param v scalar
128 * @return scalar as a multiplication of ElectricalResistance and ElectricalConductance
129 */
130 public final Dimensionless multiply(final ElectricalConductance v)
131 {
132 return new Dimensionless(this.si() * v.si(), Unitless.BASE);
133 }
134
135 /**
136 * Calculate the multiplication of ElectricalResistance and ElectricCurrent, which results in a ElectricPotential scalar.
137 * @param v scalar
138 * @return scalar as a multiplication of ElectricalResistance and ElectricCurrent
139 */
140 public final ElectricPotential multiply(final ElectricCurrent v)
141 {
142 return new ElectricPotential(this.si() * v.si(), ElectricPotential.Unit.SI);
143 }
144
145 /**
146 * Calculate the multiplication of ElectricalResistance and Duration, which results in a ElectricalInductance scalar.
147 * @param v scalar
148 * @return scalar as a multiplication of ElectricalResistance and Duration
149 */
150 public final ElectricalInductance multiply(final Duration v)
151 {
152 return new ElectricalInductance(this.si() * v.si(), ElectricalInductance.Unit.SI);
153 }
154
155 @Override
156 public ElectricalConductance reciprocal()
157 {
158 return ElectricalConductance.ofSi(1.0 / this.si());
159 }
160
161 /******************************************************************************************************/
162 /********************************************** UNIT CLASS ********************************************/
163 /******************************************************************************************************/
164
165 /**
166 * ElectricalResistance.Unit encodes the opposition to the flow of electric current.
167 * <p>
168 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
169 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
170 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
171 * @author Alexander Verbraeck
172 */
173 @SuppressWarnings("checkstyle:constantname")
174 public static class Unit extends AbstractUnit<ElectricalResistance.Unit, ElectricalResistance>
175 {
176 /** The dimensions of the electrical resistance: kgm2/s3A2. */
177 public static final SIUnit SI_UNIT = SIUnit.of("kgm2/s3A2");
178
179 /** Ohm. */
180 public static final ElectricalResistance.Unit ohm =
181 new ElectricalResistance.Unit("ohm", "\u03A9", "ohm", IdentityScale.SCALE, UnitSystem.SI_DERIVED);
182
183 /** The SI or BASE unit. */
184 public static final ElectricalResistance.Unit SI = ohm.generateSiPrefixes(false, false);
185
186 /** micro-ohm. */
187 public static final ElectricalResistance.Unit muohm = Units.resolve(ElectricalResistance.Unit.class, "muohm");
188
189 /** milli-ohm. */
190 public static final ElectricalResistance.Unit mohm = Units.resolve(ElectricalResistance.Unit.class, "mohm");
191
192 /** kilo-ohm. */
193 public static final ElectricalResistance.Unit kohm = Units.resolve(ElectricalResistance.Unit.class, "kohm");
194
195 /** mega-ohm. */
196 public static final ElectricalResistance.Unit Mohm = Units.resolve(ElectricalResistance.Unit.class, "Mohm");
197
198 /** giga-ohm. */
199 public static final ElectricalResistance.Unit Gohm = Units.resolve(ElectricalResistance.Unit.class, "Gohm");
200
201 /** ab-ohm. */
202 public static final ElectricalResistance.Unit abohm =
203 ohm.deriveUnit("abohm", "ab\u03A9", "abohm", 1.0E-9, UnitSystem.CGS_EMU);
204
205 /** stat-ohm. */
206 public static final ElectricalResistance.Unit statohm =
207 ohm.deriveUnit("stohm", "st\u03A9", "statohm", 8.987551787E11, UnitSystem.CGS_EMU);
208
209 /**
210 * Create a new ElectricalResistance unit.
211 * @param id the id or main abbreviation of the unit
212 * @param name the full name of the unit
213 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
214 * @param unitSystem the unit system such as SI or IMPERIAL
215 */
216 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
217 {
218 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
219 }
220
221 /**
222 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
223 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
224 * @param displayAbbreviation the display abbreviation of the unit
225 * @param name the full name of the unit
226 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
227 * @param unitSystem unit system, e.g. SI or Imperial
228 */
229 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
230 final UnitSystem unitSystem)
231 {
232 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
233 }
234
235 @Override
236 public SIUnit siUnit()
237 {
238 return SI_UNIT;
239 }
240
241 @Override
242 public Unit getBaseUnit()
243 {
244 return SI;
245 }
246
247 @Override
248 public ElectricalResistance ofSi(final double si)
249 {
250 return ElectricalResistance.ofSi(si);
251 }
252
253 @Override
254 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
255 final double scaleFactor, final UnitSystem unitSystem)
256 {
257 if (getScale() instanceof LinearScale ls)
258 {
259 return new ElectricalResistance.Unit(textualAbbreviation, displayAbbreviation, name,
260 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
261 }
262 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
263 }
264
265 }
266 }