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.Units;
9 import org.djunits.unit.scale.IdentityScale;
10 import org.djunits.unit.scale.LinearScale;
11 import org.djunits.unit.scale.Scale;
12 import org.djunits.unit.si.SIPrefix;
13 import org.djunits.unit.si.SIPrefixes;
14 import org.djunits.unit.si.SIUnit;
15 import org.djunits.unit.system.UnitSystem;
16
17 /**
18 * Linear object density counts the number of objects per unit of length, measured in number per meter (/m).
19 * <p>
20 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
21 * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
22 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
23 * @author Alexander Verbraeck
24 */
25 public class LinearObjectDensity extends Quantity<LinearObjectDensity>
26 {
27 /** Constant with value zero. */
28 public static final LinearObjectDensity ZERO = ofSi(0.0);
29
30 /** Constant with value one. */
31 public static final LinearObjectDensity ONE = ofSi(1.0);
32
33 /** Constant with value NaN. */
34 @SuppressWarnings("checkstyle:constantname")
35 public static final LinearObjectDensity NaN = ofSi(Double.NaN);
36
37 /** Constant with value POSITIVE_INFINITY. */
38 public static final LinearObjectDensity POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
39
40 /** Constant with value NEGATIVE_INFINITY. */
41 public static final LinearObjectDensity NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
42
43 /** Constant with value MAX_VALUE. */
44 public static final LinearObjectDensity POS_MAXVALUE = ofSi(Double.MAX_VALUE);
45
46 /** Constant with value -MAX_VALUE. */
47 public static final LinearObjectDensity NEG_MAXVALUE = ofSi(-Double.MAX_VALUE);
48
49 /** */
50 private static final long serialVersionUID = 600L;
51
52 /**
53 * Instantiate a LinearObjectDensity quantity with an SI or base value and a display unit.
54 * @param value the quantity value expressed in the SI or base unit
55 * @param displayUnit the display unit to use
56 * @param useSi use SI value when true, use value in unit when false
57 */
58 public LinearObjectDensity(final double value, final LinearObjectDensity.Unit displayUnit, final boolean useSi)
59 {
60 super(value, displayUnit, useSi);
61 }
62
63 /**
64 * Instantiate a LinearObjectDensity quantity expressed in the given unit.
65 * @param valueInUnit the quantity value expressed in the given unit
66 * @param unit the unit of the value, also acts as the display unit
67 */
68 public LinearObjectDensity(final double valueInUnit, final LinearObjectDensity.Unit unit)
69 {
70 this(valueInUnit, unit, false);
71 }
72
73 /**
74 * Return a LinearObjectDensity instance based on an SI value.
75 * @param si the si value
76 * @return the LinearObjectDensity instance based on an SI value
77 */
78 public static LinearObjectDensity ofSi(final double si)
79 {
80 return new LinearObjectDensity(si, LinearObjectDensity.Unit.SI, true);
81 }
82
83 /**
84 * Instantiate a LinearObjectDensity quantity with an SI or base value and a display unit.
85 * @param siValue the quantity value expressed in the SI or base unit
86 * @param displayUnit the display unit to use
87 * @return the LinearObjectDensity instance based on an SI value with the given display unit
88 */
89 public static LinearObjectDensity ofSi(final double siValue, final LinearObjectDensity.Unit displayUnit)
90 {
91 return new LinearObjectDensity(siValue, displayUnit, true);
92 }
93
94 @Override
95 public LinearObjectDensity instantiateSi(final double siValue, final UnitInterface<LinearObjectDensity> displayUnit)
96 {
97 return new LinearObjectDensity(siValue, (LinearObjectDensity.Unit) displayUnit, true);
98 }
99
100 /**
101 * Returns a LinearObjectDensity 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 LinearObjectDensity
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 LinearObjectDensity valueOf(final String text)
110 {
111 return Quantity.valueOf(text, ZERO);
112 }
113
114 /**
115 * Returns a LinearObjectDensity based on a value expressed in the unit.
116 * @param valueInUnit the value, expressed in the given unit
117 * @param unit the unit of the value, also acts as the display unit
118 * @return ab LinearObjectDensity representation of the value in its unit
119 */
120 public static LinearObjectDensity of(final double valueInUnit, final LinearObjectDensity.Unit unit)
121 {
122 return new LinearObjectDensity(valueInUnit, unit);
123 }
124
125 /**
126 * Returns a LinearObjectDensity based on a value and the textual representation of the unit, which can be localized.
127 * @param valueInUnit the value, expressed in the unit as given by unitString
128 * @param unitString the textual representation of the unit
129 * @return the Scalar representation of the value in its unit
130 * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
131 * @throws NullPointerException when the unitString argument is null
132 */
133 public static LinearObjectDensity of(final double valueInUnit, final String unitString)
134 {
135 return Quantity.of(valueInUnit, unitString, ZERO);
136 }
137
138 @Override
139 public LinearObjectDensity.Unit getDisplayUnit()
140 {
141 return (LinearObjectDensity.Unit) super.getDisplayUnit();
142 }
143
144 /**
145 * Calculate the division of LinearObjectDensity and LinearObjectDensity, which results in a Dimensionless quantity.
146 * @param v quantity
147 * @return quantity as a division of LinearObjectDensity and LinearObjectDensity
148 */
149 public Dimensionless divide(final LinearObjectDensity v)
150 {
151 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
152 }
153
154 /**
155 * Calculate the multiplication of LinearObjectDensity and Length, which results in a Dimensionless scalar.
156 * @param v scalar
157 * @return scalar as a multiplication of LinearObjectDensity and Length
158 */
159 public Dimensionless multiply(final Length v)
160 {
161 return new Dimensionless(this.si() * v.si(), Unitless.BASE);
162 }
163
164 /**
165 * Calculate the multiplication of LinearObjectDensity and Area, which results in a Length scalar.
166 * @param v scalar
167 * @return scalar as a multiplication of LinearObjectDensity and Area
168 */
169 public Length multiply(final Area v)
170 {
171 return new Length(this.si() * v.si(), Length.Unit.SI);
172 }
173
174 /**
175 * Calculate the multiplication of LinearObjectDensity and Energy, which results in a Force scalar.
176 * @param v scalar
177 * @return scalar as a multiplication of LinearObjectDensity and Energy
178 */
179 public Force multiply(final Energy v)
180 {
181 return new Force(this.si() * v.si(), Force.Unit.SI);
182 }
183
184 /**
185 * Calculate the multiplication of LinearObjectDensity and Speed, which results in a Frequency scalar.
186 * @param v scalar
187 * @return scalar as a multiplication of LinearObjectDensity and Speed
188 */
189 public Frequency multiply(final Speed v)
190 {
191 return new Frequency(this.si() * v.si(), Frequency.Unit.SI);
192 }
193
194 @Override
195 public Length reciprocal()
196 {
197 return Length.ofSi(1.0 / this.si());
198 }
199
200 /******************************************************************************************************/
201 /********************************************** UNIT CLASS ********************************************/
202 /******************************************************************************************************/
203
204 /**
205 * LinearObjectDensity.Unit encodes the unit for the number of objects per unit of length.
206 * <p>
207 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
208 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
209 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
210 * @author Alexander Verbraeck
211 */
212 @SuppressWarnings("checkstyle:constantname")
213 public static class Unit extends AbstractUnit<LinearObjectDensity>
214 {
215 /** The dimensions of the number of objects per unit of length: per meter (/m). */
216 public static final SIUnit SI_UNIT = SIUnit.of("/m");
217
218 /** per meter. */
219 public static final LinearObjectDensity.Unit per_m = new LinearObjectDensity.Unit("/m", "/m", "per meter",
220 IdentityScale.SCALE, UnitSystem.SI_DERIVED, SIPrefixes.getSiPrefixPer("/"));
221
222 /** The SI or BASE unit. */
223 public static final LinearObjectDensity.Unit SI = (Unit) per_m.generateSiPrefixes(false, true);
224
225 /** per millimeter. */
226 public static final LinearObjectDensity.Unit per_mm = Units.resolve(LinearObjectDensity.Unit.class, "/mm");
227
228 /** per centimeter. */
229 public static final LinearObjectDensity.Unit per_cm = Units.resolve(LinearObjectDensity.Unit.class, "/cm");
230
231 /** per decimeter. */
232 public static final LinearObjectDensity.Unit per_dm = Units.resolve(LinearObjectDensity.Unit.class, "/dm");
233
234 /** per decameter. */
235 public static final LinearObjectDensity.Unit per_dam = Units.resolve(LinearObjectDensity.Unit.class, "/dam");
236
237 /** per hectometer. */
238 public static final LinearObjectDensity.Unit per_hm = Units.resolve(LinearObjectDensity.Unit.class, "/hm");
239
240 /** per kilometer. */
241 public static final LinearObjectDensity.Unit per_km = Units.resolve(LinearObjectDensity.Unit.class, "/km");
242
243 /** per inch. */
244 public static final LinearObjectDensity.Unit per_in =
245 new LinearObjectDensity.Unit("/in", "per inch", 1.0 / Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
246
247 /** per foot. */
248 public static final LinearObjectDensity.Unit per_ft =
249 new LinearObjectDensity.Unit("/ft", "per foot", 1.0 / Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
250
251 /** per yard. */
252 public static final LinearObjectDensity.Unit per_yd =
253 new LinearObjectDensity.Unit("/yd", "per yard", 1.0 / Length.Unit.CONST_YD, UnitSystem.IMPERIAL);
254
255 /** per mile. */
256 public static final LinearObjectDensity.Unit per_mi =
257 new LinearObjectDensity.Unit("/mi", "per mile", 1.0 / Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
258
259 /**
260 * Create a new LinearObjectDensity unit.
261 * @param id the id or main abbreviation of the unit
262 * @param name the full name of the unit
263 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
264 * @param unitSystem the unit system such as SI or IMPERIAL
265 */
266 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
267 {
268 super(id, name, scaleFactorToBaseUnit, unitSystem);
269 }
270
271 /**
272 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
273 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
274 * @param displayAbbreviation the display abbreviation of the unit
275 * @param name the full name of the unit
276 * @param scale the scale to use to convert from this unit to the standard (e.g., SI, BASE) unit
277 * @param unitSystem unit system, e.g. SI or Imperial
278 * @param siPrefix the SI Prefix of this unit
279 */
280 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
281 final UnitSystem unitSystem, final SIPrefix siPrefix)
282 {
283 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem, siPrefix);
284 }
285
286 @Override
287 public SIUnit siUnit()
288 {
289 return SI_UNIT;
290 }
291
292 @Override
293 public Unit getBaseUnit()
294 {
295 return SI;
296 }
297
298 @Override
299 public LinearObjectDensity ofSi(final double si, final UnitInterface<LinearObjectDensity> displayUnit)
300 {
301 return new LinearObjectDensity(si, (Unit) displayUnit, true);
302 }
303
304 @Override
305 public LinearObjectDensity.Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation,
306 final String name, final double scaleFactor, final UnitSystem unitSystem, final SIPrefix siPrefix)
307 {
308 if (getScale() instanceof LinearScale ls)
309 {
310 return new LinearObjectDensity.Unit(textualAbbreviation, displayAbbreviation, name,
311 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem, siPrefix);
312 }
313 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
314 }
315
316 }
317
318 }