1 package org.djunits.unit;
2
3 import static org.djunits.unit.unitsystem.UnitSystem.OTHER;
4
5 import org.djunits.unit.unitsystem.UnitSystem;
6
7 /**
8 * Standard direction unit. Several conversion factors have been taken from
9 * <a href="http://en.wikipedia.org/wiki/Conversion_of_units">http://en.wikipedia.org/wiki/Conversion_of_units</a>.
10 * <p>
11 * Note that the Direction is <b>counter</b>clockwise.
12 * <p>
13 * Copyright (c) 2015-2018 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
14 * BSD-style license. See <a href="http://djunits.org/docs/license.html">DJUNITS License</a>.
15 * <p>
16 * $LastChangedDate: 2017-01-30 14:23:11 +0100 (Mon, 30 Jan 2017) $, @version $Revision: 234 $, by $Author: averbraeck $,
17 * initial version May 15, 2014 <br>
18 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
19 */
20 public class DirectionUnit extends AbsoluteLinearUnit<DirectionUnit, AngleUnit>
21 {
22 /** */
23 private static final long serialVersionUID = 20140607L;
24
25 /** The BASE unit for direction with an artificial origin. */
26 public static final DirectionUnit BASE;
27
28 /** The unit for direction with North as the origin and radians as the displacement. */
29 public static final DirectionUnit NORTH_RADIAN;
30
31 /** The unit for direction with North as the origin and degrees as the displacement. */
32 public static final DirectionUnit NORTH_DEGREE;
33
34 /** The unit for direction with East as the origin and radians as the displacement. */
35 public static final DirectionUnit EAST_RADIAN;
36
37 /** The unit for direction with East as the origin and degrees as the displacement. */
38 public static final DirectionUnit EAST_DEGREE;
39
40 static
41 {
42 BASE = new DirectionUnit("DirectionUnit.base", "DirectionUnit.base", OTHER, 1.0, 0.0, false, AngleUnit.RADIAN);
43 NORTH_RADIAN = new DirectionUnit("DirectionUnit.North(rad)", "DirectionUnit.North(radians)", OTHER, 1.0, 0.0, false,
44 AngleUnit.RADIAN);
45 NORTH_DEGREE = new DirectionUnit("DirectionUnit.North(deg)", "DirectionUnit.North(degrees)", OTHER, Math.PI / 180.0,
46 0.0, false, AngleUnit.RADIAN);
47 EAST_RADIAN = new DirectionUnit("DirectionUnit.East(rad)", "DirectionUnit.East(radians)", OTHER, 1.0, -Math.PI / 2.0,
48 false, AngleUnit.RADIAN);
49 EAST_DEGREE = new DirectionUnit("DirectionUnit.East(deg)", "DirectionUnit.East(degrees)", OTHER, Math.PI / 180.0, -90.0,
50 false, AngleUnit.RADIAN);
51 }
52
53 /**
54 * Build a DirectionUnit with a scale factor and offset to the base DirectionUnit.
55 * @param nameOrNameKey if standardUnit: the key to the locale file for the long name of the unit, otherwise the name itself
56 * @param abbreviationOrAbbreviationKey if standardUnit: the key to the locale file for the abbreviation of the unit,
57 * otherwise the abbreviation itself
58 * @param unitSystem the unit system, e.g. SI or Imperial
59 * @param scaleFactor multiply a value in this unit by the factor to convert to the given reference unit
60 * @param offset the offset to the reference unit to add to convert to the standard (e.g., BASE) unit
61 * @param standardUnit indicates whether it is a standard unit with a definition in the locale, or a user-defined unit
62 * @param relativeUnit the corresponding relative unit belonging to this absolute unit
63 */
64 private DirectionUnit(final String nameOrNameKey, final String abbreviationOrAbbreviationKey, final UnitSystem unitSystem,
65 final double scaleFactor, final double offset, final boolean standardUnit, final AngleUnit relativeUnit)
66 {
67 super(nameOrNameKey, abbreviationOrAbbreviationKey, unitSystem, scaleFactor, offset, standardUnit, relativeUnit);
68 }
69
70 /**
71 * Build a user-defined DirectionUnit with a scale factor and offset to the base DirectionUnit.
72 * @param name the long name of the unit
73 * @param abbreviation the abbreviation of the unit
74 * @param unitSystem the unit system, e.g. SI or Imperial
75 * @param scaleFactor multiply a value in this unit by the factor to convert to the given reference unit
76 * @param offset the offset to the reference unit to add to convert to the standard (e.g., BASE) unit
77 * @param relativeUnit the corresponding relative unit belonging to this absolute unit
78 */
79 public DirectionUnit(final String name, final String abbreviation, final UnitSystem unitSystem, final double scaleFactor,
80 final double offset, final AngleUnit relativeUnit)
81 {
82 this(name, abbreviation, unitSystem, scaleFactor, offset, false, relativeUnit);
83 }
84
85 /** {@inheritDoc} */
86 @Override
87 public final DirectionUnit getStandardUnit()
88 {
89 return BASE;
90 }
91
92 /** {@inheritDoc} */
93 @Override
94 public final String getSICoefficientsString()
95 {
96 return "1";
97 }
98
99 }