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 * Area is a measure of a two-dimensional surface, expressed in square meters (m2).
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 Area extends Quantity<Area>
23 {
24 /** Constant with value zero. */
25 public static final Area ZERO = ofSi(0.0);
26
27 /** Constant with value one. */
28 public static final Area ONE = ofSi(1.0);
29
30 /** Constant with value NaN. */
31 @SuppressWarnings("checkstyle:constantname")
32 public static final Area NaN = ofSi(Double.NaN);
33
34 /** Constant with value POSITIVE_INFINITY. */
35 public static final Area POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
36
37 /** Constant with value NEGATIVE_INFINITY. */
38 public static final Area NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
39
40 /** Constant with value MAX_VALUE. */
41 public static final Area POS_MAXVALUE = ofSi(Double.MAX_VALUE);
42
43 /** Constant with value -MAX_VALUE. */
44 public static final Area NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
45
46 /** */
47 private static final long serialVersionUID = 600L;
48
49 /**
50 * Instantiate a Area 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 Area(final double value, final Area.Unit displayUnit, final boolean useSi)
56 {
57 super(value, displayUnit, useSi);
58 }
59
60 /**
61 * Instantiate a Area 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 Area(final double valueInUnit, final Area.Unit unit)
66 {
67 this(valueInUnit, unit, false);
68 }
69
70 /**
71 * Return a Area instance based on an SI value.
72 * @param si the si value
73 * @return the Area instance based on an SI value
74 */
75 public static Area ofSi(final double si)
76 {
77 return new Area(si, Area.Unit.SI, true);
78 }
79
80 /**
81 * Instantiate a Area 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 Area instance based on an SI value with the given display unit
85 */
86 public static Area ofSi(final double siValue, final Area.Unit displayUnit)
87 {
88 return new Area(siValue, displayUnit, true);
89 }
90
91 @Override
92 public Area instantiateSi(final double siValue, final UnitInterface<Area> displayUnit)
93 {
94 return new Area(siValue, (Area.Unit) displayUnit, true);
95 }
96
97 /**
98 * Returns a Area representation of a textual representation of a value with a unit. The String representation that can be
99 * parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed,
100 * but not required, between the value and the unit.
101 * @param text the textual representation to parse into a Area
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 Area valueOf(final String text)
107 {
108 return Quantity.valueOf(text, ZERO);
109 }
110
111 /**
112 * Returns a Area 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 Area representation of the value in its unit
116 */
117 public static Area of(final double valueInUnit, final Area.Unit unit)
118 {
119 return new Area(valueInUnit, unit);
120 }
121
122 /**
123 * Returns a Area 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 Area of(final double valueInUnit, final String unitString)
131 {
132 return Quantity.of(valueInUnit, unitString, ZERO);
133 }
134
135 @Override
136 public Area.Unit getDisplayUnit()
137 {
138 return (Area.Unit) super.getDisplayUnit();
139 }
140
141 /**
142 * Calculate the division of Area and Area, which results in a Dimensionless scalar.
143 * @param v scalar
144 * @return scalar as a division of Area and Area
145 */
146 public Dimensionless divide(final Area v)
147 {
148 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
149 }
150
151 /**
152 * Calculate the multiplication of Area and ArealObjectDensity, which results in a Dimensionless scalar.
153 * @param v scalar
154 * @return scalar as a multiplication of Area and ArealObjectDensity
155 */
156 public Dimensionless multiply(final ArealObjectDensity v)
157 {
158 return new Dimensionless(this.si() * v.si(), Unitless.BASE);
159 }
160
161 /**
162 * Calculate the multiplication of Area and Length, which results in a Volume scalar.
163 * @param v scalar
164 * @return scalar as a multiplication of Area and Length
165 */
166 public Volume multiply(final Length v)
167 {
168 return new Volume(this.si() * v.si(), Volume.Unit.SI);
169 }
170
171 /**
172 * Calculate the division of Area and LinearObjectDensity, which results in a Volume scalar.
173 * @param v scalar
174 * @return scalar as a division of Area and LinearObjectDensity
175 */
176 public Volume divide(final LinearObjectDensity v)
177 {
178 return new Volume(this.si() / v.si(), Volume.Unit.SI);
179 }
180
181 /**
182 * Calculate the division of Area and Volume, which results in a LinearObjectDensity scalar.
183 * @param v scalar
184 * @return scalar as a division of Area and Volume
185 */
186 public LinearObjectDensity divide(final Volume v)
187 {
188 return new LinearObjectDensity(this.si() / v.si(), LinearObjectDensity.Unit.SI);
189 }
190
191 /**
192 * Calculate the division of Area and Length, which results in a Length scalar.
193 * @param v scalar
194 * @return scalar as a division of Area and Length
195 */
196 public Length divide(final Length v)
197 {
198 return new Length(this.si() / v.si(), Length.Unit.SI);
199 }
200
201 /**
202 * Calculate the multiplication of Area and LinearObjectDensity, which results in a Length scalar.
203 * @param v scalar
204 * @return scalar as a multiplication of Area and LinearObjectDensity
205 */
206 public Length multiply(final LinearObjectDensity v)
207 {
208 return new Length(this.si() * v.si(), Length.Unit.SI);
209 }
210
211 /**
212 * Calculate the multiplication of Area and Speed, which results in a FlowVolume scalar.
213 * @param v scalar
214 * @return scalar as a multiplication of Area and Speed
215 */
216 public FlowVolume multiply(final Speed v)
217 {
218 return new FlowVolume(this.si() * v.si(), FlowVolume.Unit.SI);
219 }
220
221 /**
222 * Calculate the multiplication of Area and Pressure, which results in a Force scalar.
223 * @param v scalar
224 * @return scalar as a multiplication of Area and Pressure
225 */
226 public Force multiply(final Pressure v)
227 {
228 return new Force(this.si() * v.si(), Force.Unit.SI);
229 }
230
231 /**
232 * Calculate the multiplication of Area and Illuminance, which results in a LuminousFlux scalar.
233 * @param v scalar
234 * @return scalar as a multiplication of Area and Illuminance
235 */
236 public LuminousFlux multiply(final Illuminance v)
237 {
238 return new LuminousFlux(this.si() * v.si(), LuminousFlux.Unit.SI);
239 }
240
241 @Override
242 public ArealObjectDensity reciprocal()
243 {
244 return ArealObjectDensity.ofSi(1.0 / this.si());
245 }
246
247 /******************************************************************************************************/
248 /********************************************** UNIT CLASS ********************************************/
249 /******************************************************************************************************/
250
251 /**
252 * Area.Unit encodes the area unit (length x length).
253 * <p>
254 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
255 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
256 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
257 * @author Alexander Verbraeck
258 */
259 @SuppressWarnings("checkstyle:constantname")
260 public static class Unit extends AbstractUnit<Area>
261 {
262 /** The dimensions of Area: m2. */
263 public static final SIUnit SI_UNIT = SIUnit.of("m2");
264
265 /** Square meter. */
266 public static final Area.Unit m2 = new Area.Unit("m2", "square meter", 1.0, UnitSystem.SI_BASE);
267
268 /** The SI or BASE unit. */
269 public static final Area.Unit SI = m2;
270
271 /** Square kilometer. */
272 public static final Area.Unit km2 = m2.deriveUnit("km2", "square kilometer", 1.0E6, UnitSystem.SI_BASE);
273
274 /** Square hectometer. */
275 public static final Area.Unit hm2 = m2.deriveUnit("hm2", "square hectometer", 1.0E4, UnitSystem.SI_BASE);
276
277 /** Square decameter. */
278 public static final Area.Unit dam2 = m2.deriveUnit("dam2", "square decameter", 1.0E2, UnitSystem.SI_BASE);
279
280 /** Square decimeter. */
281 public static final Area.Unit dm2 = m2.deriveUnit("dm2", "square decimeter", 1.0E-2, UnitSystem.SI_BASE);
282
283 /** Square centimeter. */
284 public static final Area.Unit cm2 = m2.deriveUnit("cm2", "square centimeter", 1.0E-4, UnitSystem.SI_BASE);
285
286 /** Square millimeter. */
287 public static final Area.Unit mm2 = m2.deriveUnit("mm2", "square millimeter", 1.0E-6, UnitSystem.SI_BASE);
288
289 /** Square micrometer. */
290 public static final Area.Unit mum2 =
291 m2.deriveUnit("mum2", "\u03BCm2", "square micrometer", 1.0E-12, UnitSystem.SI_BASE, null);
292
293 /** Square nanometer. */
294 public static final Area.Unit nm2 = m2.deriveUnit("nm2", "square nanometer", 1.0E-18, UnitSystem.SI_BASE);
295
296 /** Square picometer. */
297 public static final Area.Unit pm2 = m2.deriveUnit("pm2", "square picometer", 1.0E-24, UnitSystem.SI_BASE);
298
299 /** Square femtometer. */
300 public static final Area.Unit fm2 = m2.deriveUnit("fm2", "square femtometer", 1.0E-30, UnitSystem.SI_BASE);
301
302 /** Square attometer. */
303 public static final Area.Unit am2 = m2.deriveUnit("am2", "square attometer", 1.0E-36, UnitSystem.SI_BASE);
304
305 /** centiare. */
306 public static final Area.Unit ca = new Area.Unit("ca", "centiare", 1.0, UnitSystem.OTHER);
307
308 /** are. */
309 public static final Area.Unit a = new Area.Unit("a", "are", 100.0, UnitSystem.OTHER);
310
311 /** hectare. */
312 public static final Area.Unit ha = new Area.Unit("ha", "hectare", 100.0 * 100.0, UnitSystem.OTHER);
313
314 /** mile2. */
315 public static final Area.Unit mi2 =
316 new Area.Unit("mi2", "square mile", Length.Unit.CONST_MI * Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
317
318 /** Nautical mile2. */
319 public static final Area.Unit NM2 =
320 new Area.Unit("NM2", "square nautical mile", Length.Unit.CONST_NM * Length.Unit.CONST_NM, UnitSystem.OTHER);
321
322 /** ft2. */
323 public static final Area.Unit ft2 =
324 new Area.Unit("ft2", "square foot", Length.Unit.CONST_FT * Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
325
326 /** in2. */
327 public static final Area.Unit in2 =
328 new Area.Unit("in2", "square inch", Length.Unit.CONST_IN * Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
329
330 /** yd2. */
331 public static final Area.Unit yd2 =
332 new Area.Unit("yd2", "square yard", Length.Unit.CONST_YD * Length.Unit.CONST_YD, UnitSystem.IMPERIAL);
333
334 /** acre (international) defined as 1/640 square mile or 4840 square yards. */
335 public static final Area.Unit ac =
336 new Area.Unit("ac", "acre", Length.Unit.CONST_MI * Length.Unit.CONST_MI / 640.0, UnitSystem.IMPERIAL);
337
338 /**
339 * Create a new Area unit.
340 * @param id the id or main abbreviation of the unit
341 * @param name the full name of the unit
342 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
343 * @param unitSystem the unit system such as SI or IMPERIAL
344 */
345 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
346 {
347 super(id, name, scaleFactorToBaseUnit, unitSystem);
348 }
349
350 /**
351 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
352 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
353 * @param displayAbbreviation the display abbreviation of the unit
354 * @param name the full name of the unit
355 * @param scale the scale to use to convert from this unit to the standard (e.g., SI, BASE) unit
356 * @param unitSystem unit system, e.g. SI or Imperial
357 * @param siPrefix the SI Prefix of this unit
358 */
359 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
360 final UnitSystem unitSystem, final SIPrefix siPrefix)
361 {
362 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem, siPrefix);
363 }
364
365 @Override
366 public SIUnit siUnit()
367 {
368 return SI_UNIT;
369 }
370
371 @Override
372 public Unit getBaseUnit()
373 {
374 return SI;
375 }
376
377 @Override
378 public Area ofSi(final double si, final UnitInterface<Area> displayUnit)
379 {
380 return new Area(si, (Unit) displayUnit, true);
381 }
382
383 @Override
384 public Area.Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
385 final double scaleFactor, final UnitSystem unitSystem, final SIPrefix siPrefix)
386 {
387 if (getScale() instanceof LinearScale ls)
388 {
389 return new Area.Unit(textualAbbreviation, displayAbbreviation, name,
390 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem, siPrefix);
391 }
392 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
393 }
394
395 @Override
396 public Area.Unit deriveUnit(final String abbreviation, final String name, final double scaleFactor,
397 final UnitSystem unitSystem)
398 {
399 return (Unit) super.deriveUnit(abbreviation, name, scaleFactor, unitSystem);
400 }
401
402 }
403
404 }