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>
22 {
23 /** Constant with value zero. */
24 public static final LinearObjectDensity ZERO = ofSi(0.0);
25
26 /** Constant with value one. */
27 public static final LinearObjectDensity ONE = ofSi(1.0);
28
29 /** Constant with value NaN. */
30 @SuppressWarnings("checkstyle:constantname")
31 public static final LinearObjectDensity NaN = ofSi(Double.NaN);
32
33 /** Constant with value POSITIVE_INFINITY. */
34 public static final LinearObjectDensity POSITIVE_INFINITY = ofSi(Double.POSITIVE_INFINITY);
35
36 /** Constant with value NEGATIVE_INFINITY. */
37 public static final LinearObjectDensity NEGATIVE_INFINITY = ofSi(Double.NEGATIVE_INFINITY);
38
39 /** Constant with value MAX_VALUE. */
40 public static final LinearObjectDensity POS_MAXVALUE = ofSi(Double.MAX_VALUE);
41
42 /** Constant with value -MAX_VALUE. */
43 public static final LinearObjectDensity NEG_MAXVALUE = 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 valueInUnit the value, expressed in the unit
51 * @param unit the unit in which the value is expressed
52 */
53 public LinearObjectDensity(final double valueInUnit, final LinearObjectDensity.Unit unit)
54 {
55 super(valueInUnit, unit);
56 }
57
58 /**
59 * Return a LinearObjectDensity instance based on an SI value.
60 * @param si the si value
61 * @return the LinearObjectDensity instance based on an SI value
62 */
63 public static LinearObjectDensity ofSi(final double si)
64 {
65 return new LinearObjectDensity(si, LinearObjectDensity.Unit.SI);
66 }
67
68 @Override
69 public LinearObjectDensity instantiateSi(final double si)
70 {
71 return ofSi(si);
72 }
73
74 @Override
75 public SIUnit siUnit()
76 {
77 return LinearObjectDensity.Unit.SI_UNIT;
78 }
79
80 /**
81 * Returns a LinearObjectDensity representation of a textual representation of a value with a unit. The String
82 * representation that can be parsed is the double value in the unit, followed by a localized or English abbreviation of the
83 * unit. Spaces are allowed, but not required, between the value and the unit.
84 * @param text the textual representation to parse into a LinearObjectDensity
85 * @return the Scalar representation of the value in its unit
86 * @throws IllegalArgumentException when the text cannot be parsed
87 * @throws NullPointerException when the text argument is null
88 */
89 public static LinearObjectDensity valueOf(final String text)
90 {
91 return Quantity.valueOf(text, ZERO);
92 }
93
94 /**
95 * Returns a LinearObjectDensity based on a value and the textual representation of the unit, which can be localized.
96 * @param valueInUnit the value, expressed in the unit as given by unitString
97 * @param unitString the textual representation of the unit
98 * @return the Scalar representation of the value in its unit
99 * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
100 * @throws NullPointerException when the unitString argument is null
101 */
102 public static LinearObjectDensity of(final double valueInUnit, final String unitString)
103 {
104 return Quantity.of(valueInUnit, unitString, ZERO);
105 }
106
107 @Override
108 public LinearObjectDensity.Unit getDisplayUnit()
109 {
110 return (LinearObjectDensity.Unit) super.getDisplayUnit();
111 }
112
113 /**
114 * Calculate the division of LinearObjectDensity and LinearObjectDensity, which results in a Dimensionless quantity.
115 * @param v quantity
116 * @return quantity as a division of LinearObjectDensity and LinearObjectDensity
117 */
118 public final Dimensionless divide(final LinearObjectDensity v)
119 {
120 return new Dimensionless(this.si() / v.si(), Unitless.BASE);
121 }
122
123 /**
124 * Calculate the multiplication of LinearObjectDensity and Length, which results in a Dimensionless scalar.
125 * @param v scalar
126 * @return scalar as a multiplication of LinearObjectDensity and Length
127 */
128 public final Dimensionless multiply(final Length v)
129 {
130 return new Dimensionless(this.si() * v.si(), Unitless.BASE);
131 }
132
133 /**
134 * Calculate the multiplication of LinearObjectDensity and Area, which results in a Length scalar.
135 * @param v scalar
136 * @return scalar as a multiplication of LinearObjectDensity and Area
137 */
138 public final Length multiply(final Area v)
139 {
140 return new Length(this.si() * v.si(), Length.Unit.SI);
141 }
142
143 /**
144 * Calculate the multiplication of LinearObjectDensity and Energy, which results in a Force scalar.
145 * @param v scalar
146 * @return scalar as a multiplication of LinearObjectDensity and Energy
147 */
148 public final Force multiply(final Energy v)
149 {
150 return new Force(this.si() * v.si(), Force.Unit.SI);
151 }
152
153 /**
154 * Calculate the multiplication of LinearObjectDensity and Speed, which results in a Frequency scalar.
155 * @param v scalar
156 * @return scalar as a multiplication of LinearObjectDensity and Speed
157 */
158 public final Frequency multiply(final Speed v)
159 {
160 return new Frequency(this.si() * v.si(), Frequency.Unit.SI);
161 }
162
163 @Override
164 public Length reciprocal()
165 {
166 return Length.ofSi(1.0 / this.si());
167 }
168
169 /******************************************************************************************************/
170 /********************************************** UNIT CLASS ********************************************/
171 /******************************************************************************************************/
172
173 /**
174 * LinearObjectDensity.Unit encodes the unit for the number of objects per unit of length.
175 * <p>
176 * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved.
177 * See for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
178 * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
179 * @author Alexander Verbraeck
180 */
181 @SuppressWarnings("checkstyle:constantname")
182 public static class Unit extends AbstractUnit<LinearObjectDensity.Unit, LinearObjectDensity>
183 {
184 /** The dimensions of the number of objects per unit of length: per meter (/m). */
185 public static final SIUnit SI_UNIT = SIUnit.of("/m");
186
187 /** per meter. */
188 public static final LinearObjectDensity.Unit per_m =
189 new LinearObjectDensity.Unit("/m", "per meter", 1.0, UnitSystem.SI_DERIVED);
190
191 /** The SI or BASE unit. */
192 public static final LinearObjectDensity.Unit SI = per_m.generateSiPrefixes(false, true);
193
194 /** per millimeter. */
195 public static final LinearObjectDensity.Unit per_mm = Units.resolve(LinearObjectDensity.Unit.class, "/mm");
196
197 /** per centimeter. */
198 public static final LinearObjectDensity.Unit per_cm = Units.resolve(LinearObjectDensity.Unit.class, "/cm");
199
200 /** per decimeter. */
201 public static final LinearObjectDensity.Unit per_dm = Units.resolve(LinearObjectDensity.Unit.class, "/dm");
202
203 /** per decameter. */
204 public static final LinearObjectDensity.Unit per_dam = Units.resolve(LinearObjectDensity.Unit.class, "/dam");
205
206 /** per hectometer. */
207 public static final LinearObjectDensity.Unit per_hm = Units.resolve(LinearObjectDensity.Unit.class, "/hm");
208
209 /** per kilometer. */
210 public static final LinearObjectDensity.Unit per_km = Units.resolve(LinearObjectDensity.Unit.class, "/km");
211
212 /** per inch. */
213 public static final LinearObjectDensity.Unit per_in =
214 new LinearObjectDensity.Unit("/in", "per inch", 1.0 / Length.Unit.CONST_IN, UnitSystem.IMPERIAL);
215
216 /** per foot. */
217 public static final LinearObjectDensity.Unit per_ft =
218 new LinearObjectDensity.Unit("/ft", "per foot", 1.0 / Length.Unit.CONST_FT, UnitSystem.IMPERIAL);
219
220 /** per yard. */
221 public static final LinearObjectDensity.Unit per_yd =
222 new LinearObjectDensity.Unit("/yd", "per yard", 1.0 / Length.Unit.CONST_YD, UnitSystem.IMPERIAL);
223
224 /** per mile. */
225 public static final LinearObjectDensity.Unit per_mi =
226 new LinearObjectDensity.Unit("/mi", "per mile", 1.0 / Length.Unit.CONST_MI, UnitSystem.IMPERIAL);
227
228 /**
229 * Create a new LinearObjectDensity unit.
230 * @param id the id or main abbreviation of the unit
231 * @param name the full name of the unit
232 * @param scaleFactorToBaseUnit the scale factor of the unit to convert it TO the base (SI) unit
233 * @param unitSystem the unit system such as SI or IMPERIAL
234 */
235 public Unit(final String id, final String name, final double scaleFactorToBaseUnit, final UnitSystem unitSystem)
236 {
237 super(id, name, new LinearScale(scaleFactorToBaseUnit), unitSystem);
238 }
239
240 /**
241 * Return a derived unit for this unit, with textual abbreviation(s) and a display abbreviation.
242 * @param textualAbbreviation the textual abbreviation of the unit, which doubles as the id
243 * @param displayAbbreviation the display abbreviation of the unit
244 * @param name the full name of the unit
245 * @param scale the scale to use to convert between this unit and the standard (e.g., SI, BASE) unit
246 * @param unitSystem unit system, e.g. SI or Imperial
247 */
248 public Unit(final String textualAbbreviation, final String displayAbbreviation, final String name, final Scale scale,
249 final UnitSystem unitSystem)
250 {
251 super(textualAbbreviation, displayAbbreviation, name, scale, unitSystem);
252 }
253
254 @Override
255 public SIUnit siUnit()
256 {
257 return SI_UNIT;
258 }
259
260 @Override
261 public Unit getBaseUnit()
262 {
263 return SI;
264 }
265
266 @Override
267 public LinearObjectDensity ofSi(final double si)
268 {
269 return LinearObjectDensity.ofSi(si);
270 }
271
272 @Override
273 public Unit deriveUnit(final String textualAbbreviation, final String displayAbbreviation, final String name,
274 final double scaleFactor, final UnitSystem unitSystem)
275 {
276 if (getScale() instanceof LinearScale ls)
277 {
278 return new LinearObjectDensity.Unit(textualAbbreviation, displayAbbreviation, name,
279 new LinearScale(ls.getScaleFactorToBaseUnit() * scaleFactor), unitSystem);
280 }
281 throw new UnitRuntimeException("Only possible to derive a unit from a unit with a linear scale");
282 }
283
284 }
285 }