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 * Linear object density counts the number of objects per unit of length, measured in number per meter (/m).
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 LinearObjectDensity extends Quantity<LinearObjectDensity, LinearObjectDensity.Unit>
22 {
23 /** Constant with value zero. */
24 public static final LinearObjectDensity ZERO = LinearObjectDensity.ofSi(0.0);
25
26 /** Constant with value one. */
27 public static final LinearObjectDensity ONE = LinearObjectDensity.ofSi(1.0);
28
29 /** Constant with value NaN. */
30 @SuppressWarnings("checkstyle:constantname")
31 public static final LinearObjectDensity NaN = LinearObjectDensity.ofSi(Double.NaN);
32
33 /** Constant with value POSITIVE_INFINITY. */
34 public static final LinearObjectDensity POSITIVE_INFINITY = LinearObjectDensity.ofSi(Double.POSITIVE_INFINITY);
35
36 /** Constant with value NEGATIVE_INFINITY. */
37 public static final LinearObjectDensity NEGATIVE_INFINITY = LinearObjectDensity.ofSi(Double.NEGATIVE_INFINITY);
38
39 /** Constant with value MAX_VALUE. */
40 public static final LinearObjectDensity POS_MAXVALUE = LinearObjectDensity.ofSi(Double.MAX_VALUE);
41
42 /** Constant with value -MAX_VALUE. */
43 public static final LinearObjectDensity NEG_MAXVALUE = LinearObjectDensity.ofSi(-Double.MAX_VALUE);
44
45 /** */
46 private static final long serialVersionUID = 600L;
47
48 /**
49 * Instantiate a LinearObjectDensity 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 LinearObjectDensity(final double value, final LinearObjectDensity.Unit unit)
54 {
55 super(value, unit);
56 }
57
58 /**
59 * Instantiate a LinearObjectDensity 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 LinearObjectDensity(final double value, final String abbreviation)
64 {
65 this(value, Units.resolve(LinearObjectDensity.Unit.class, abbreviation));
66 }
67
68 /**
69 * Construct LinearObjectDensity quantity.
70 * @param value Scalar from which to construct this instance
71 */
72 public LinearObjectDensity(final LinearObjectDensity value)
73 {
74 super(value.si(), LinearObjectDensity.Unit.SI);
75 setDisplayUnit(value.getDisplayUnit());
76 }
77
78 /**
79 * Return a LinearObjectDensity instance based on an SI value.
80 * @param si the si value
81 * @return the LinearObjectDensity instance based on an SI value
82 */
83 public static LinearObjectDensity ofSi(final double si)
84 {
85 return new LinearObjectDensity(si, LinearObjectDensity.Unit.SI);
86 }
87
88 @Override
89 public LinearObjectDensity instantiate(final double si)
90 {
91 return ofSi(si);
92 }
93
94 @Override
95 public SIUnit siUnit()
96 {
97 return LinearObjectDensity.Unit.SI_UNIT;
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 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 LinearObjectDensity of(final double value, final String unitString)
123 {
124 return Quantity.of(value, unitString, ZERO);
125 }
126
127 /**
128 * Calculate the division of LinearObjectDensity and LinearObjectDensity, which results in a Dimensionless quantity.
129 * @param v quantity
130 * @return quantity as a division of LinearObjectDensity and LinearObjectDensity
131 */
132 public final Dimensionless divide(final LinearObjectDensity v)
133 {
134 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
135 }
136
137 /**
138 * Calculate the multiplication of LinearObjectDensity and Length, which results in a Dimensionless scalar.
139 * @param v scalar
140 * @return scalar as a multiplication of LinearObjectDensity and Length
141 */
142 public final Dimensionless multiply(final Length v)
143 {
144 return new Dimensionless(this.si() * v.si(), Unitless.BASE);
145 }
146
147 /**
148 * Calculate the multiplication of LinearObjectDensity and Area, which results in a Length scalar.
149 * @param v scalar
150 * @return scalar as a multiplication of LinearObjectDensity and Area
151 */
152 public final Length multiply(final Area v)
153 {
154 return new Length(this.si() * v.si(), Length.Unit.SI);
155 }
156
157 /**
158 * Calculate the multiplication of LinearObjectDensity and Energy, which results in a Force scalar.
159 * @param v scalar
160 * @return scalar as a multiplication of LinearObjectDensity and Energy
161 */
162 public final Force multiply(final Energy v)
163 {
164 return new Force(this.si() * v.si(), Force.Unit.SI);
165 }
166
167 /**
168 * Calculate the multiplication of LinearObjectDensity and Speed, which results in a Frequency scalar.
169 * @param v scalar
170 * @return scalar as a multiplication of LinearObjectDensity and Speed
171 */
172 public final Frequency multiply(final Speed v)
173 {
174 return new Frequency(this.si() * v.si(), Frequency.Unit.SI);
175 }
176
177 @Override
178 public Length reciprocal()
179 {
180 return Length.ofSi(1.0 / this.si());
181 }
182
183 /******************************************************************************************************/
184 /********************************************** UNIT CLASS ********************************************/
185 /******************************************************************************************************/
186
187 /**
188 * LinearObjectDensity.Unit encodes the unit for the number of objects per unit of length.
189 * <p>
190 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
191 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
192 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
193 * @author Alexander Verbraeck
194 */
195 @SuppressWarnings("checkstyle:constantname")
196 public static class Unit extends AbstractUnit<LinearObjectDensity.Unit, LinearObjectDensity>
197 {
198 /** The dimensions of the number of objects per unit of length: per meter (/m). */
199 public static final SIUnit SI_UNIT = SIUnit.of("/m");
200
201 /** per meter. */
202 public static final LinearObjectDensity.Unit per_m =
203 new LinearObjectDensity.Unit("/m", "per meter", 1.0, UnitSystem.SI_DERIVED);
204
205 /** The SI or BASE unit. */
206 public static final LinearObjectDensity.Unit SI = per_m.generateSiPrefixes(false, true);
207
208 /** per millimeter. */
209 public static final LinearObjectDensity.Unit per_mm = Units.resolve(LinearObjectDensity.Unit.class, "/mm");
210
211 /** per centimeter. */
212 public static final LinearObjectDensity.Unit per_cm = Units.resolve(LinearObjectDensity.Unit.class, "/cm");
213
214 /** per decimeter. */
215 public static final LinearObjectDensity.Unit per_dm = Units.resolve(LinearObjectDensity.Unit.class, "/dm");
216
217 /** per decameter. */
218 public static final LinearObjectDensity.Unit per_dam = Units.resolve(LinearObjectDensity.Unit.class, "/dam");
219
220 /** per hectometer. */
221 public static final LinearObjectDensity.Unit per_hm = Units.resolve(LinearObjectDensity.Unit.class, "/hm");
222
223 /** per kilometer. */
224 public static final LinearObjectDensity.Unit per_km = Units.resolve(LinearObjectDensity.Unit.class, "/km");
225
226 /** per inch. */
227 public static final LinearObjectDensity.Unit per_in =
228 new LinearObjectDensity.Unit("/in", "per inch", 1.0 / Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
229
230 /** per foot. */
231 public static final LinearObjectDensity.Unit per_ft =
232 new LinearObjectDensity.Unit("/ft", "per foot", 1.0 / Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
233
234 /** per yard. */
235 public static final LinearObjectDensity.Unit per_yd =
236 new LinearObjectDensity.Unit("/yd", "per yard", 1.0 / Length.Unit.CONST_YD, UnitSystem.IMPERIAL);
237
238 /** per mile. */
239 public static final LinearObjectDensity.Unit per_mi =
240 new LinearObjectDensity.Unit("/mi", "per mile", 1.0 / Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
241
242 /**
243 * Create a new LinearObjectDensity unit.
244 * @param id the id or main abbreviation of the unit
245 * @param name the full name of the unit
246 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
247 * @param unitSystem the unit system such as SI or IMPERIAL
248 */
249 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
250 {
251 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
252 }
253
254 /**
255 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
256 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
257 * @param displayAbbreviation the display abbreviation of the unit
258 * @param name the full name of the unit
259 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
260 * @param unitSystem unit system, e.g. SI or Imperial
261 */
262 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
263 final UnitSystem unitSystem)
264 {
265 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
266 }
267
268 @Override
269 public SIUnit siUnit()
270 {
271 return SI_UNIT;
272 }
273
274 @Override
275 public Unit getBaseUnit()
276 {
277 return SI;
278 }
279
280 @Override
281 public LinearObjectDensity ofSi(final double si)
282 {
283 return LinearObjectDensity.ofSi(si);
284 }
285
286 @Override
287 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
288 final double scaleFactor, final UnitSystem unitSystem)
289 {
290 if (getScale() instanceof LinearScale ls)
291 {
292 return new LinearObjectDensity.Unit(textualAbbreviation, displayAbbreviation, name,
293 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
294 }
295 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
296 }
297
298 }
299 }