1 package org.djunits.quantity;
2
3 import org.djunits.quantity.def.Quantity;
4 import org.djunits.unit.AbstractUnit;
5 import org.djunits.unit.UnitInterface;
6 import org.djunits.unit.UnitRuntimeException;
7 import org.djunits.unit.Unitless;
8 import org.djunits.unit.scale.LinearScale;
9 import org.djunits.unit.scale.Scale;
10 import org.djunits.unit.si.SIPrefix;
11 import org.djunits.unit.si.SIUnit;
12 import org.djunits.unit.system.UnitSystem;
13
14 /**
15 * Luminous flux is the total perceived power of light emitted by a source, measured in lumens (lm).
16 * <p>
17 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
18 * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
19 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
20 * @author Alexander Verbraeck
21 */
22 public class LuminousFlux extends Quantity<LuminousFlux>
23 {
24 /** Constant with value zero. */
25 public static final LuminousFlux ZERO = ofSi(0.0);
26
27 /** Constant with value one. */
28 public static final LuminousFlux ONE = ofSi(1.0);
29
30 /** Constant with value NaN. */
31 @SuppressWarnings("checkstyle:constantname")
32 public static final LuminousFlux NaN = ofSi(Double.NaN);
33
34 /** Constant with value POSITIVE_INFINITY. */
35 public static final LuminousFlux POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
36
37 /** Constant with value NEGATIVE_INFINITY. */
38 public static final LuminousFlux NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
39
40 /** Constant with value MAX_VALUE. */
41 public static final LuminousFlux POS_MAXVALUE = ofSi(Double.MAX_VALUE);
42
43 /** Constant with value -MAX_VALUE. */
44 public static final LuminousFlux NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
45
46 /** */
47 private static final long serialVersionUID = 600L;
48
49 /**
50 * Instantiate a LuminousFlux quantity with an SI or base value and a display unit.
51 * @param value the quantity value expressed in the SI or base unit
52 * @param displayUnit the display unit to use
53 * @param useSi use SI value when true, use value in unit when false
54 */
55 public LuminousFlux(final double value, final LuminousFlux.Unit displayUnit, final boolean useSi)
56 {
57 super(value, displayUnit, useSi);
58 }
59
60 /**
61 * Instantiate a LuminousFlux quantity expressed in the given unit.
62 * @param valueInUnit the quantity value expressed in the given unit
63 * @param unit the unit of the value, also acts as the display unit
64 */
65 public LuminousFlux(final double valueInUnit, final LuminousFlux.Unit unit)
66 {
67 this(valueInUnit, unit, false);
68 }
69
70 /**
71 * Return a LuminousFlux instance based on an SI value.
72 * @param si the si value
73 * @return the LuminousFlux instance based on an SI value
74 */
75 public static LuminousFlux ofSi(final double si)
76 {
77 return new LuminousFlux(si, LuminousFlux.Unit.SI, true);
78 }
79
80 /**
81 * Instantiate a LuminousFlux quantity with an SI or base value and a display unit.
82 * @param siValue the quantity value expressed in the SI or base unit
83 * @param displayUnit the display unit to use
84 * @return the LuminousFlux instance based on an SI value with the given display unit
85 */
86 public static LuminousFlux ofSi(final double siValue, final LuminousFlux.Unit displayUnit)
87 {
88 return new LuminousFlux(siValue, displayUnit, true);
89 }
90
91 @Override
92 public LuminousFlux instantiateSi(final double siValue, final UnitInterface<LuminousFlux> displayUnit)
93 {
94 return new LuminousFlux(siValue, (LuminousFlux.Unit) displayUnit, true);
95 }
96
97 /**
98 * Returns a LuminousFlux representation of a textual representation of a value with a unit. The String representation that
99 * can be parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are
100 * allowed, but not required, between the value and the unit.
101 * @param text the textual representation to parse into a LuminousFlux
102 * @return the Scalar representation of the value in its unit
103 * @throws IllegalArgumentException when the text cannot be parsed
104 * @throws NullPointerException when the text argument is null
105 */
106 public static LuminousFlux valueOf(final String text)
107 {
108 return Quantity.valueOf(text, ZERO);
109 }
110
111 /**
112 * Returns a LuminousFlux based on a value expressed in the unit.
113 * @param valueInUnit the value, expressed in the given unit
114 * @param unit the unit of the value, also acts as the display unit
115 * @return ab LuminousFlux representation of the value in its unit
116 */
117 public static LuminousFlux of(final double valueInUnit, final LuminousFlux.Unit unit)
118 {
119 return new LuminousFlux(valueInUnit, unit);
120 }
121
122 /**
123 * Returns a LuminousFlux based on a value and the textual representation of the unit, which can be localized.
124 * @param valueInUnit the value, expressed in the unit as given by unitString
125 * @param unitString the textual representation of the unit
126 * @return the Scalar representation of the value in its unit
127 * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
128 * @throws NullPointerException when the unitString argument is null
129 */
130 public static LuminousFlux of(final double valueInUnit, final String unitString)
131 {
132 return Quantity.of(valueInUnit, unitString, ZERO);
133 }
134
135 @Override
136 public LuminousFlux.Unit getDisplayUnit()
137 {
138 return (LuminousFlux.Unit) super.getDisplayUnit();
139 }
140
141 /**
142 * Calculate the division of LuminousFlux and LuminousFlux, which results in a Dimensionless quantity.
143 * @param v quantity
144 * @return quantity as a division of LuminousFlux and LuminousFlux
145 */
146 public Dimensionless divide(final LuminousFlux v)
147 {
148 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
149 }
150
151 /**
152 * Calculate the division of LuminousFlux and Area, which results in a Illuminance scalar.
153 * @param v scalar
154 * @return scalar as a division of LuminousFlux and Area
155 */
156 public Illuminance divide(final Area v)
157 {
158 return new Illuminance(this.si() / v.si(), Illuminance.Unit.SI);
159 }
160
161 /**
162 * Calculate the division of LuminousFlux and Illuminance, which results in a Area scalar.
163 * @param v scalar
164 * @return scalar as a division of LuminousFlux and Illuminance
165 */
166 public Area divide(final Illuminance v)
167 {
168 return new Area(this.si() / v.si(), Area.Unit.SI);
169 }
170
171 /**
172 * Calculate the division of LuminousFlux and LuminousIntensity, which results in a SolidAngle scalar.
173 * @param v scalar
174 * @return scalar as a division of LuminousFlux and LuminousIntensity
175 */
176 public SolidAngle divide(final LuminousIntensity v)
177 {
178 return new SolidAngle(this.si() / v.si(), SolidAngle.Unit.SI);
179 }
180
181 /**
182 * Calculate the division of LuminousFlux and SolidAngle, which results in a LuminousIntensity scalar.
183 * @param v scalar
184 * @return scalar as a division of LuminousFlux and SolidAngle
185 */
186 public LuminousIntensity divide(final SolidAngle v)
187 {
188 return new LuminousIntensity(this.si() / v.si(), LuminousIntensity.Unit.SI);
189 }
190
191 /******************************************************************************************************/
192 /********************************************** UNIT CLASS ********************************************/
193 /******************************************************************************************************/
194
195 /**
196 * LuminousFlux.Unit encodes the units of total perceived power of light emitted by a source.
197 * <p>
198 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
199 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
200 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
201 * @author Alexander Verbraeck
202 */
203 @SuppressWarnings("checkstyle:constantname")
204 public static class Unit extends AbstractUnit<LuminousFlux>
205 {
206 /** The dimensions of luminous flux: cd.sr. */
207 public static final SIUnit SI_UNIT = SIUnit.of("cdsr");
208
209 /** Lumen. */
210 public static final LuminousFlux.Unit lm = new LuminousFlux.Unit("lm", "lumen", 1.0, UnitSystem.SI_DERIVED);
211
212 /** The SI or BASE unit. */
213 public static final LuminousFlux.Unit SI = lm;
214
215 /**
216 * Create a new LuminousFlux unit.
217 * @param id the id or main abbreviation of the unit
218 * @param name the full name of the unit
219 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
220 * @param unitSystem the unit system such as SI or IMPERIAL
221 */
222 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
223 {
224 super(id, name, scaleFactorToBaseUnit, unitSystem);
225 }
226
227 /**
228 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
229 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
230 * @param displayAbbreviation the display abbreviation of the unit
231 * @param name the full name of the unit
232 * @param scale the scale to use to convert from this unit to the standard (e.g., SI, BASE) unit
233 * @param unitSystem unit system, e.g. SI or Imperial
234 * @param siPrefix the SI Prefix of this unit
235 */
236 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
237 final UnitSystem unitSystem, final SIPrefix siPrefix)
238 {
239 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem, siPrefix);
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 @Override
255 public LuminousFlux ofSi(final double si, final UnitInterface<LuminousFlux> displayUnit)
256 {
257 return new LuminousFlux(si, (Unit) displayUnit, true);
258 }
259
260 @Override
261 public LuminousFlux.Unit deriveUnit(final String abbreviation, final String name, final double scaleFactor,
262 final UnitSystem unitSystem)
263 {
264 return (Unit) super.deriveUnit(abbreviation, name, scaleFactor, unitSystem);
265 }
266
267 @Override
268 public LuminousFlux.Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation,
269 final String name, final double scaleFactor, final UnitSystem unitSystem, final SIPrefix siPrefix)
270 {
271 if (getScale() instanceof LinearScale ls)
272 {
273 return new LuminousFlux.Unit(textualAbbreviation, displayAbbreviation, name,
274 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem, siPrefix);
275 }
276 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
277 }
278
279 }
280
281 }