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 * Area is a measure of a two-dimensional surface, expressed in square meters (m2).
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 Area extends Quantity<Area, Area.Unit>
22 {
23 /** Constant with value zero. */
24 public static final Area ZERO = Area.ofSi(0.0);
25
26 /** Constant with value one. */
27 public static final Area ONE = Area.ofSi(1.0);
28
29 /** Constant with value NaN. */
30 @SuppressWarnings("checkstyle:constantname")
31 public static final Area NaN = Area.ofSi(Double.NaN);
32
33 /** Constant with value POSITIVE_INFINITY. */
34 public static final Area POSITIVE_INFINITY = Area.ofSi(Double.POSITIVE_INFINITY);
35
36 /** Constant with value NEGATIVE_INFINITY. */
37 public static final Area NEGATIVE_INFINITY = Area.ofSi(Double.NEGATIVE_INFINITY);
38
39 /** Constant with value MAX_VALUE. */
40 public static final Area POS_MAXVALUE = Area.ofSi(Double.MAX_VALUE);
41
42 /** Constant with value -MAX_VALUE. */
43 public static final Area NEG_MAXVALUE = Area.ofSi(-Double.MAX_VALUE);
44
45 /** */
46 private static final long serialVersionUID = 600L;
47
48 /**
49 * Instantiate a Area 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 Area(final double value, final Area.Unit unit)
54 {
55 super(value, unit);
56 }
57
58 /**
59 * Instantiate a Area 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 Area(final double value, final String abbreviation)
64 {
65 this(value, Units.resolve(Area.Unit.class, abbreviation));
66 }
67
68 /**
69 * Construct Area quantity.
70 * @param value Scalar from which to construct this instance
71 */
72 public Area(final Area value)
73 {
74 super(value.si(), Area.Unit.SI);
75 setDisplayUnit(value.getDisplayUnit());
76 }
77
78 /**
79 * Return a Area instance based on an SI value.
80 * @param si the si value
81 * @return the Area instance based on an SI value
82 */
83 public static Area ofSi(final double si)
84 {
85 return new Area(si, Area.Unit.SI);
86 }
87
88 @Override
89 public Area instantiate(final double si)
90 {
91 return ofSi(si);
92 }
93
94 @Override
95 public SIUnit siUnit()
96 {
97 return Area.Unit.SI_UNIT;
98 }
99
100 /**
101 * Returns a Area representation of a textual representation of a value with a unit. The String representation that can be
102 * parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are allowed,
103 * but not required, between the value and the unit.
104 * @param text the textual representation to parse into a Area
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 Area valueOf(final String text)
110 {
111 return Quantity.valueOf(text, ZERO);
112 }
113
114 /**
115 * Returns a Area 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 Area of(final double value, final String unitString)
123 {
124 return Quantity.of(value, unitString, ZERO);
125 }
126
127 /**
128 * Calculate the division of Area and Area, which results in a Dimensionless scalar.
129 * @param v scalar
130 * @return scalar as a division of Area and Area
131 */
132 public final Dimensionless divide(final Area v)
133 {
134 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
135 }
136
137 /**
138 * Calculate the multiplication of Area and ArealObjectDensity, which results in a Dimensionless scalar.
139 * @param v scalar
140 * @return scalar as a multiplication of Area and ArealObjectDensity
141 */
142 public final Dimensionless multiply(final ArealObjectDensity v)
143 {
144 return new Dimensionless(this.si() * v.si(), Unitless.BASE);
145 }
146
147 /**
148 * Calculate the multiplication of Area and Length, which results in a Volume scalar.
149 * @param v scalar
150 * @return scalar as a multiplication of Area and Length
151 */
152 public final Volume multiply(final Length v)
153 {
154 return new Volume(this.si() * v.si(), Volume.Unit.SI);
155 }
156
157 /**
158 * Calculate the division of Area and LinearObjectDensity, which results in a Volume scalar.
159 * @param v scalar
160 * @return scalar as a division of Area and LinearObjectDensity
161 */
162 public final Volume divide(final LinearObjectDensity v)
163 {
164 return new Volume(this.si() / v.si(), Volume.Unit.SI);
165 }
166
167 /**
168 * Calculate the division of Area and Volume, which results in a LinearObjectDensity scalar.
169 * @param v scalar
170 * @return scalar as a division of Area and Volume
171 */
172 public final LinearObjectDensity divide(final Volume v)
173 {
174 return new LinearObjectDensity(this.si() / v.si(), LinearObjectDensity.Unit.SI);
175 }
176
177 /**
178 * Calculate the division of Area and Length, which results in a Length scalar.
179 * @param v scalar
180 * @return scalar as a division of Area and Length
181 */
182 public final Length divide(final Length v)
183 {
184 return new Length(this.si() / v.si(), Length.Unit.SI);
185 }
186
187 /**
188 * Calculate the multiplication of Area and LinearObjectDensity, which results in a Length scalar.
189 * @param v scalar
190 * @return scalar as a multiplication of Area and LinearObjectDensity
191 */
192 public final Length multiply(final LinearObjectDensity v)
193 {
194 return new Length(this.si() * v.si(), Length.Unit.SI);
195 }
196
197 /**
198 * Calculate the multiplication of Area and Speed, which results in a FlowVolume scalar.
199 * @param v scalar
200 * @return scalar as a multiplication of Area and Speed
201 */
202 public final FlowVolume multiply(final Speed v)
203 {
204 return new FlowVolume(this.si() * v.si(), FlowVolume.Unit.SI);
205 }
206
207 /**
208 * Calculate the multiplication of Area and Pressure, which results in a Force scalar.
209 * @param v scalar
210 * @return scalar as a multiplication of Area and Pressure
211 */
212 public final Force multiply(final Pressure v)
213 {
214 return new Force(this.si() * v.si(), Force.Unit.SI);
215 }
216
217 /**
218 * Calculate the multiplication of Area and Illuminance, which results in a LuminousFlux scalar.
219 * @param v scalar
220 * @return scalar as a multiplication of Area and Illuminance
221 */
222 public final LuminousFlux multiply(final Illuminance v)
223 {
224 return new LuminousFlux(this.si() * v.si(), LuminousFlux.Unit.SI);
225 }
226
227 @Override
228 public ArealObjectDensity reciprocal()
229 {
230 return ArealObjectDensity.ofSi(1.0 / this.si());
231 }
232
233 /******************************************************************************************************/
234 /********************************************** UNIT CLASS ********************************************/
235 /******************************************************************************************************/
236
237 /**
238 * Area.Unit encodes the area unit (length x length).
239 * <p>
240 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
241 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
242 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
243 * @author Alexander Verbraeck
244 */
245 @SuppressWarnings("checkstyle:constantname")
246 public static class Unit extends AbstractUnit<Area.Unit, Area>
247 {
248 /** The dimensions of Area: m2. */
249 public static final SIUnit SI_UNIT = SIUnit.of("m2");
250
251 /** Square meter. */
252 public static final Area.Unit m2 = new Area.Unit("m2", "square meter", 1.0, UnitSystem.SI_BASE);
253
254 /** The SI or BASE unit. */
255 public static final Area.Unit SI = m2;
256
257 /** Square kilometer. */
258 public static final Area.Unit km2 = m2.deriveUnit("km2", "square kilometer", 1.0E6, UnitSystem.SI_BASE);
259
260 /** Square hectometer. */
261 public static final Area.Unit hm2 = m2.deriveUnit("hm2", "square hectometer", 1.0E4, UnitSystem.SI_BASE);
262
263 /** Square decameter. */
264 public static final Area.Unit dam2 = m2.deriveUnit("dam2", "square decameter", 1.0E2, UnitSystem.SI_BASE);
265
266 /** Square decimeter. */
267 public static final Area.Unit dm2 = m2.deriveUnit("dm2", "square decimeter", 1.0E-2, UnitSystem.SI_BASE);
268
269 /** Square centimeter. */
270 public static final Area.Unit cm2 = m2.deriveUnit("cm2", "square centimeter", 1.0E-4, UnitSystem.SI_BASE);
271
272 /** Square millimeter. */
273 public static final Area.Unit mm2 = m2.deriveUnit("mm2", "square millimeter", 1.0E-6, UnitSystem.SI_BASE);
274
275 /** Square micrometer. */
276 public static final Area.Unit mum2 =
277 m2.deriveUnit("mum2", "\u03BCm2", "square micrometer", 1.0E-12, UnitSystem.SI_BASE);
278
279 /** Square nanometer. */
280 public static final Area.Unit nm2 = m2.deriveUnit("nm2", "square nanometer", 1.0E-18, UnitSystem.SI_BASE);
281
282 /** Square picometer. */
283 public static final Area.Unit pm2 = m2.deriveUnit("pm2", "square picometer", 1.0E-24, UnitSystem.SI_BASE);
284
285 /** Square femtometer. */
286 public static final Area.Unit fm2 = m2.deriveUnit("fm2", "square femtometer", 1.0E-30, UnitSystem.SI_BASE);
287
288 /** Square attometer. */
289 public static final Area.Unit am2 = m2.deriveUnit("am2", "square attometer", 1.0E-36, UnitSystem.SI_BASE);
290
291 /** centiare. */
292 public static final Area.Unit ca = new Area.Unit("ca", "centiare", 1.0, UnitSystem.OTHER);
293
294 /** are. */
295 public static final Area.Unit a = new Area.Unit("a", "are", 100.0, UnitSystem.OTHER);
296
297 /** hectare. */
298 public static final Area.Unit ha = new Area.Unit("ha", "hectare", 100.0 * 100.0, UnitSystem.OTHER);
299
300 /** mile2. */
301 public static final Area.Unit mi2 =
302 new Area.Unit("mi2", "square mile", Length.Unit.CONST_MI * Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
303
304 /** Nautical mile2. */
305 public static final Area.Unit NM2 =
306 new Area.Unit("NM2", "square nautical mile", Length.Unit.CONST_NM * Length.Unit.CONST_NM, UnitSystem.OTHER);
307
308 /** ft2. */
309 public static final Area.Unit ft2 =
310 new Area.Unit("ft2", "square foot", Length.Unit.CONST_FT * Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
311
312 /** in2. */
313 public static final Area.Unit in2 =
314 new Area.Unit("in2", "square inch", Length.Unit.CONST_IN * Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
315
316 /** yd2. */
317 public static final Area.Unit yd2 =
318 new Area.Unit("yd2", "square yard", Length.Unit.CONST_YD * Length.Unit.CONST_YD, UnitSystem.IMPERIAL);
319
320 /** acre (international) defined as 1/640 square mile or 4840 square yards. */
321 public static final Area.Unit ac =
322 new Area.Unit("ac", "acre", Length.Unit.CONST_MI * Length.Unit.CONST_MI / 640.0, UnitSystem.IMPERIAL);
323
324 /**
325 * Create a new Area unit.
326 * @param id the id or main abbreviation of the unit
327 * @param name the full name of the unit
328 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
329 * @param unitSystem the unit system such as SI or IMPERIAL
330 */
331 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
332 {
333 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
334 }
335
336 /**
337 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
338 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
339 * @param displayAbbreviation the display abbreviation of the unit
340 * @param name the full name of the unit
341 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
342 * @param unitSystem unit system, e.g. SI or Imperial
343 */
344 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
345 final UnitSystem unitSystem)
346 {
347 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
348 }
349
350 @Override
351 public SIUnit siUnit()
352 {
353 return SI_UNIT;
354 }
355
356 @Override
357 public Unit getBaseUnit()
358 {
359 return SI;
360 }
361
362 @Override
363 public Area ofSi(final double si)
364 {
365 return Area.ofSi(si);
366 }
367
368 @Override
369 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
370 final double scaleFactor, final UnitSystem unitSystem)
371 {
372 if (getScale() instanceof LinearScale ls)
373 {
374 return new Area.Unit(textualAbbreviation, displayAbbreviation, name,
375 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
376 }
377 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
378 }
379
380 }
381 }