1 package org.djunits.unit;
2
3 import static org.djunits.unit.unitsystem.UnitSystem.SI_DERIVED;
4
5 import org.djunits.unit.unitsystem.UnitSystem;
6
7 /**
8 * Standard density unit based on mass and length.
9 * <p>
10 * Copyright (c) 2015-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
11 * BSD-style license. See <a href="http://djunits.org/docs/license.html">DJUNITS License</a>.
12 * <p>
13 * $LastChangedDate: 2019-03-02 19:06:46 +0100 (Sat, 02 Mar 2019) $, @version $Revision: 342 $, by $Author: averbraeck $,
14 * initial version May 15, 2014 <br>
15 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
16 */
17 public class DensityUnit extends LinearUnit<DensityUnit>
18 {
19 /** */
20 private static final long serialVersionUID = 20140607L;
21
22 /** the actual mass unit, e.g. kg. */
23 private final MassUnit massUnit;
24
25 /** the actual length unit, e.g. meter. */
26 private final LengthUnit lengthUnit;
27
28 /** The SI unit for standard density is kg/m^3. */
29 public static final DensityUnit SI;
30
31 /** kg/m^3. */
32 public static final DensityUnit KG_PER_METER_3;
33
34 /** g/cm^3. */
35 public static final DensityUnit GRAM_PER_CENTIMETER_3;
36
37 static
38 {
39 SI = new DensityUnit(MassUnit.KILOGRAM, LengthUnit.METER, "DensityUnit.kg/m^3", SI_DERIVED);
40 KG_PER_METER_3 = SI;
41 GRAM_PER_CENTIMETER_3 = new DensityUnit(MassUnit.GRAM, LengthUnit.CENTIMETER, "DensityUnit.g/cm^3", SI_DERIVED);
42 }
43
44 /**
45 * Define density unit based on mass and length. You can define units like kg/m^3 here.
46 * @param massUnit MassUnit; the unit of mass for the density unit, e.g., kg
47 * @param lengthUnit LengthUnit; the unit of length for the density unit, e.g., meter
48 * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
49 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
50 */
51 private DensityUnit(final MassUnit massUnit, final LengthUnit lengthUnit, final String abbreviationKey,
52 final UnitSystem unitSystem)
53 {
54 super(abbreviationKey, unitSystem, KG_PER_METER_3,
55 massUnit.getScaleFactor() / Math.pow(lengthUnit.getScaleFactor(), 3.0));
56 this.massUnit = massUnit;
57 this.lengthUnit = lengthUnit;
58 }
59
60 /**
61 * Define user defined density unit based on mass and length. You can define units like kg/in^3 here.
62 * @param massUnit MassUnit; the unit of mass for the density unit, e.g., kg
63 * @param lengthUnit LengthUnit; the unit of length for the density unit, e.g., meter
64 * @param name String; the long name of the unit
65 * @param abbreviation String; the abbreviation of the unit
66 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
67 */
68 public DensityUnit(final MassUnit massUnit, final LengthUnit lengthUnit, final String name, final String abbreviation,
69 final UnitSystem unitSystem)
70 {
71 super(name, abbreviation, unitSystem, KG_PER_METER_3,
72 massUnit.getScaleFactor() / Math.pow(lengthUnit.getScaleFactor(), 3.0));
73 this.massUnit = massUnit;
74 this.lengthUnit = lengthUnit;
75 }
76
77 /**
78 * Build a unit with a conversion factor to another unit.
79 * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
80 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
81 * @param referenceUnit DensityUnit; the unit to convert to
82 * @param scaleFactorToReferenceUnit double; multiply a value in this unit by the factor to convert to the given reference
83 * unit
84 */
85 private DensityUnit(final String abbreviationKey, final UnitSystem unitSystem, final DensityUnit referenceUnit,
86 final double scaleFactorToReferenceUnit)
87 {
88 super(abbreviationKey, unitSystem, referenceUnit, scaleFactorToReferenceUnit);
89 this.massUnit = referenceUnit.getMassUnit();
90 this.lengthUnit = referenceUnit.getLengthUnit();
91 }
92
93 /**
94 * Build a user-defined unit with a conversion factor to another unit.
95 * @param name String; the long name of the unit
96 * @param abbreviation String; the abbreviation of the unit
97 * @param unitSystem UnitSystem; the unit system, e.g. SI or Imperial
98 * @param referenceUnit DensityUnit; the unit to convert to
99 * @param scaleFactorToReferenceUnit double; multiply a value in this unit by the factor to convert to the given reference
100 * unit
101 */
102 public DensityUnit(final String name, final String abbreviation, final UnitSystem unitSystem,
103 final DensityUnit referenceUnit, final double scaleFactorToReferenceUnit)
104 {
105 super(name, abbreviation, unitSystem, referenceUnit, scaleFactorToReferenceUnit);
106 this.massUnit = referenceUnit.getMassUnit();
107 this.lengthUnit = referenceUnit.getLengthUnit();
108 }
109
110 /**
111 * @return massUnit
112 */
113 public final MassUnit getMassUnit()
114 {
115 return this.massUnit;
116 }
117
118 /**
119 * @return lengthUnit
120 */
121 public final LengthUnit getLengthUnit()
122 {
123 return this.lengthUnit;
124 }
125
126 /** {@inheritDoc} */
127 @Override
128 public final DensityUnit getStandardUnit()
129 {
130 return KG_PER_METER_3;
131 }
132
133 /** {@inheritDoc} */
134 @Override
135 public final String getSICoefficientsString()
136 {
137 return "kg/m3";
138 }
139
140 }