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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.sis.measure;
import javax.measure.Dimension;
import javax.measure.Unit;
import javax.measure.UnitConverter;
import javax.measure.format.ParserException;
import javax.measure.Quantity;
import javax.measure.quantity.*;
import javax.measure.quantity.Angle; // Because of name collision with Angle in this SIS package.
import org.opengis.geometry.DirectPosition; // For javadoc
import org.opengis.referencing.cs.AxisDirection; // For javadoc
import org.apache.sis.util.Static;
import org.apache.sis.util.resources.Errors;
import org.apache.sis.internal.util.Constants;
import static org.apache.sis.measure.UnitRegistry.SI;
import static org.apache.sis.measure.UnitRegistry.ACCEPTED;
import static org.apache.sis.measure.UnitRegistry.IMPERIAL;
import static org.apache.sis.measure.UnitRegistry.OTHER;
import static org.apache.sis.measure.UnitRegistry.PREFIXABLE;
/**
* Provides constants for various Units of Measurement together with static methods working on {@link Unit} instances.
* Unit names and definitions in this class follow the definitions provided in the EPSG geodetic dataset
* (when the unit exists in that dataset),
* except “year” which has been renamed “{@linkplain #TROPICAL_YEAR tropical year}”.
* This class focuses on the most commonly used units in the geospatial domain:
* angular units ({@linkplain #DEGREE degree}, {@linkplain #ARC_SECOND arc-second}, …),
* linear units ({@linkplain #KILOMETRE kilometre}, {@linkplain #NAUTICAL_MILE nautical mile}, …) and
* temporal units ({@linkplain #DAY day}, {@linkplain #TROPICAL_YEAR year}, …),
* but some other kind of units are also provided for completeness.
* The main quantities are listed below, together with some related units:
*
* <table class="sis">
* <caption>Some quantities and related units</caption>
* <tr><th colspan="2">Quantity type</th><th>System unit</th><th>Some conventional units</th></tr>
*
* <tr><td style="padding-top:15px" colspan="4"><b>Fundamental:</b></td></tr>
* <tr><td>{@link Length}</td> <td>(L)</td> <td>{@link #METRE}</td> <td>{@link #CENTIMETRE}, {@link #KILOMETRE}, {@link #NAUTICAL_MILE}, {@link #STATUTE_MILE}, {@link #FOOT}</td></tr>
* <tr><td>{@link Mass}</td> <td>(M)</td> <td>{@link #KILOGRAM}</td> <td></td></tr>
* <tr><td>{@link Time}</td> <td>(T)</td> <td>{@link #SECOND}</td> <td>{@link #MILLISECOND}, {@link #MINUTE}, {@link #HOUR}, {@link #DAY}, {@link #WEEK}, {@link #TROPICAL_YEAR}</td></tr>
* <tr><td>{@link ElectricCurrent}</td> <td>(I)</td> <td>{@link #AMPERE}</td> <td></td></tr>
* <tr><td>{@link Temperature}</td> <td>(Θ)</td> <td>{@link #KELVIN}</td> <td>{@link #CELSIUS}, {@link #FAHRENHEIT}</td></tr>
* <tr><td>{@link AmountOfSubstance}</td> <td>(N)</td> <td>{@link #MOLE}</td> <td></td></tr>
* <tr><td>{@link LuminousIntensity}</td> <td>(J)</td> <td>{@link #CANDELA}</td> <td></td></tr>
*
* <tr><td style="padding-top:15px" colspan="4"><b>Dimensionless:</b></td></tr>
* <tr><td>{@link Angle}</td> <td></td> <td>{@link #RADIAN}</td> <td>{@link #DEGREE}, {@link #ARC_MINUTE}, {@link #ARC_SECOND}, {@link #GRAD}</td></tr>
* <tr><td>{@link SolidAngle}</td> <td></td> <td>{@link #STERADIAN}</td> <td></td></tr>
*
* <tr><td style="padding-top:15px" colspan="4"><b>Derived:</b></td></tr>
* <tr><td>{@link Area}</td> <td>(A)</td> <td>{@link #SQUARE_METRE}</td> <td>{@link #HECTARE}</td></tr>
* <tr><td>{@link Volume}</td> <td>(V)</td> <td>{@link #CUBIC_METRE}</td> <td></td></tr>
* <tr><td>{@link Speed}</td> <td>(ν)</td> <td>{@link #METRES_PER_SECOND}</td> <td>{@link #KILOMETRES_PER_HOUR}</td></tr>
* <tr><td>{@link Pressure}</td> <td></td> <td>{@link #PASCAL}</td> <td>{@link #HECTOPASCAL}, {@link #DECIBAR}, {@link #BAR}, {@link #ATMOSPHERE}</td></tr>
* </table>
*
* @author Martin Desruisseaux (IRD, Geomatys)
* @version 1.0
* @since 0.3
* @module
*/
public final class Units extends Static {
/**
* Unit of measurement defined as 10<sup>-9</sup> metres (1 nm). This unit is often used in
* {@linkplain org.apache.sis.metadata.iso.content.DefaultBand#getBoundUnits() wavelength measurements}.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE}
* and the unlocalized name is "nanometre".
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI units:</td> <td style="word-spacing:1em"><u>{@code NANOMETRE}</u>, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @see org.apache.sis.metadata.iso.content.DefaultBand#getBoundUnits()
*
* @since 0.8
*/
public static final Unit<Length> NANOMETRE;
/**
* Unit of measurement defined as 0.001 metres (1 mm).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “millimetre” and the identifier is EPSG:1025.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, <u>{@code MILLIMETRE}</u>, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> MILLIMETRE;
/**
* Unit of measurement defined as 0.01 metres (1 cm).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “centimetre” and the identifier is EPSG:1033.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, <u>{@code CENTIMETRE}</u>, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> CENTIMETRE;
/**
* The SI base unit for distances (m).
* The unlocalized name is “metre” and the identifier is EPSG:9001.
* This is the base of all other {@linkplain #isLinear(Unit) linear} units.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <u><b>{@code METRE}</b></u>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> METRE;
/**
* Unit of measurement defined as 1000 metres (1 km).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “kilometre” and the identifier is EPSG:9036.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, <u>{@code KILOMETRE}</u>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #KILOMETRES_PER_HOUR}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> KILOMETRE;
/**
* Unit of measurement defined as exactly 1852 metres (1 M).
* This is approximately the distance between two parallels of latitude
* separated by one {@linkplain #ARC_MINUTE arc-minute}.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “nautical mile” and the identifier is EPSG:9030.
*
* <p>There is no internationally agreed symbol for nautical mile. Apache SIS uses “M” in agreement with the
* International Hydrographic Organization (IHO) and the International Bureau of Weights and Measures (BIPM).
* But “NM” and “nmi” are also in use.</p>
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, <u>{@code NAUTICAL_MILE}</u>.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #KILOMETRES_PER_HOUR}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> NAUTICAL_MILE;
/**
* Unit of measurement defined as exactly 1609.344 metres (1 mi).
* This unit is often named “mile” without qualifier, but Apache SIS uses “statute mile”
* for emphasing the difference with {@linkplain #NAUTICAL_MILE nautical mile}.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE}.
* The unlocalized name is “statute mile” but is localized as "international mile" in the US
* for avoiding confusion with the US survey mile.
* The identifier is EPSG:9093.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, <u>{@code STATUTE_MILE}</u>, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #KILOMETRES_PER_HOUR}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> STATUTE_MILE;
/**
* Unit of measurement approximately equals to 0.3048006096… metres.
* The legal definition is exactly 12/39.37 metres.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “US survey foot” and the identifier is EPSG:9003.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, <u>{@code US_SURVEY_FOOT}</u>, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> US_SURVEY_FOOT;
/**
* Unit of measurement defined as 0.3047972654 metres.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “Clarke’s foot” and the identifier is EPSG:9005.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, {@link #FOOT}, <u>{@code CLARKE_FOOT}</u>, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> CLARKE_FOOT;
/**
* Unit of measurement defined as exactly 0.3048 metres (1 ft).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE},
* the unlocalized name is “foot” and the identifier is EPSG:9002.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, {@link #INCH}, <u>{@code FOOT}</u>, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> FOOT;
/**
* Unit of measurement defined as 2.54 centimetres (1 in).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE}
* and the unlocalized name is “inch”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #POINT}, <u>{@code INCH}</u>, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> INCH;
/**
* Unit of measurement defined as 0.013837 inch (1 pt).
* This is commonly used to measure the height of a font.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRE}
* and the unlocalized name is “point”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI length units:</td> <td style="word-spacing:1em">{@link #NANOMETRE}, {@link #MILLIMETRE}, {@link #CENTIMETRE}, <b>{@link #METRE}</b>, {@link #KILOMETRE}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em"><u>{@code POINT}</u>, {@link #INCH}, {@link #FOOT}, {@link #CLARKE_FOOT}, {@link #US_SURVEY_FOOT}, {@link #STATUTE_MILE}, {@link #NAUTICAL_MILE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SQUARE_METRE}, {@link #CUBIC_METRE}, {@link #METRES_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Length> POINT;
/**
* The SI derived unit for area (m²).
* The unlocalized name is “square metre”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI area units:</td> <td style="word-spacing:1em"><u><b>{@code SQUARE_METRE}</b></u>, {@link #HECTARE}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #CUBIC_METRE}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Area> SQUARE_METRE;
/**
* Unit of measurement defined as 10,000 square metres (1 ha).
* One hectare is exactly equals to one hectometre (1 hm²).
* While not an SI unit, the hectare is often used in the measurement of land.
* The unlocalized name is “hectare”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI area units:</td> <td style="word-spacing:1em"><b>{@link #SQUARE_METRE}</b>, <u>{@code HECTARE}</u>.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #CUBIC_METRE}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Area> HECTARE;
/**
* The SI derived unit for volume (m³).
* The unlocalized name is “cubic metre”.
*
* @since 0.8
*/
public static final Unit<Volume> CUBIC_METRE;
/**
* The unit for litre volume (L, l or ℓ).
* The unlocalized name is “litre”.
*
* @since 0.8
*/
public static final Unit<Volume> LITRE;
/**
* The SI unit for solid angles (sr).
* The unlocalized name is “steradian”.
*
* @since 0.8
*/
public static final Unit<SolidAngle> STERADIAN;
/**
* Unit of measurement defined as 10<sup>-6</sup> radians (1 µrad).
* The distance of one microradian of latitude on Earth is approximately 2 millimetres.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #RADIAN},
* the unlocalized name is “microradian” and the identifier is EPSG:9109.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI angle units:</td> <td style="word-spacing:1em"><u>{@code MICRORADIAN}</u>, <b>{@link #RADIAN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DEGREE}, {@link #ARC_MINUTE}, {@link #ARC_SECOND}, {@link #GRAD}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #STERADIAN}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Angle> MICRORADIAN;
/**
* The SI unit for plane angles (rad).
* There is 2π radians in a circle.
* The unlocalized name is “radian” and the identifier is EPSG:9101.
* This is the base of all other {@linkplain #isAngular(Unit) angular} units.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI angle units:</td> <td style="word-spacing:1em">{@link #MICRORADIAN}, <u><b>{@code RADIAN}</b></u>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DEGREE}, {@link #ARC_MINUTE}, {@link #ARC_SECOND}, {@link #GRAD}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #STERADIAN}, {@link #RADIANS_PER_SECOND}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Angle> RADIAN;
/**
* Unit of measurement defined as π/180 radians (1°).
* There is 360° in a circle.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #RADIAN},
* the unlocalized name is “degree” and the identifier is EPSG:9102.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI angle units:</td> <td style="word-spacing:1em">{@link #MICRORADIAN}, <b>{@link #RADIAN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em"><u>{@code DEGREE}</u>, {@link #ARC_MINUTE}, {@link #ARC_SECOND}, {@link #GRAD}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #STERADIAN}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Angle> DEGREE;
/**
* Unit of measurement defined as 1/60 degree (1′).
* The distance of one arc-minute of latitude on Earth is approximately 1852 metres
* (one {@linkplain #NAUTICAL_MILE nautical mile}).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #RADIAN},
* the unlocalized name is “arc-minute” and the identifier is EPSG:9103.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI angle units:</td> <td style="word-spacing:1em">{@link #MICRORADIAN}, <b>{@link #RADIAN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DEGREE}, <u>{@code ARC_MINUTE}</u>, {@link #ARC_SECOND}, {@link #GRAD}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #STERADIAN}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Angle> ARC_MINUTE;
/**
* Unit of measurement defined as 1/(60×60) degree (1″).
* The distance of one arc-second of latitude on Earth is approximately 31 metres.
* This unit of measurement is used for rotation terms in
* {@linkplain org.apache.sis.referencing.datum.BursaWolfParameters Bursa-Wolf parameters}.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #RADIAN},
* the unlocalized name is “arc-second” and the identifier is EPSG:9104.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI angle units:</td> <td style="word-spacing:1em">{@link #MICRORADIAN}, <b>{@link #RADIAN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DEGREE}, {@link #ARC_MINUTE}, <u>{@code ARC_SECOND}</u>, {@link #GRAD}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #STERADIAN}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Angle> ARC_SECOND;
/**
* Unit of measurement defined as π/200 radians (1 grad).
* There is 400 grads in a circle.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #RADIAN},
* the unlocalized name is “grad”, but the “gon” alias is also accepted.
* The identifier is EPSG:9105.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI angle units:</td> <td style="word-spacing:1em">{@link #MICRORADIAN}, <b>{@link #RADIAN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DEGREE}, {@link #ARC_MINUTE}, {@link #ARC_SECOND}, <u>{@code GRAD}</u>.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #STERADIAN}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Angle> GRAD;
/**
* Unit of measurement defined as 10<sup>-3</sup> seconds (1 ms).
* This unit is useful for inter-operability with various methods from the standard Java library.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #SECOND}
* and the unlocalized name is “millisecond”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em"><u>{@code MILLISECOND}</u>, <b>{@link #SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #MINUTE}, {@link #HOUR}, {@link #DAY}, {@link #WEEK}, {@link #TROPICAL_YEAR}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #METRES_PER_SECOND}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @see java.util.concurrent.TimeUnit#MILLISECONDS
*
* @since 0.3
*/
public static final Unit<Time> MILLISECOND;
/**
* The SI base unit for durations (s).
* The unlocalized name is “second” and the identifier is EPSG:1040.
* This is the base of all other {@linkplain #isTemporal(Unit) temporal} units.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em">{@link #MILLISECOND}, <u><b>{@link #SECOND}</b></u>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #MINUTE}, {@link #HOUR}, {@link #DAY}, {@link #WEEK}, {@link #TROPICAL_YEAR}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #METRES_PER_SECOND}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Time> SECOND;
/**
* Unit of measurement defined as 60 seconds (1 min).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #SECOND}
* and the unlocalized name is “minute”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em">{@link #MILLISECOND}, <b>{@link #SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em"><u>{@code MINUTE}</u>, {@link #HOUR}, {@link #DAY}, {@link #WEEK}, {@link #TROPICAL_YEAR}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #METRES_PER_SECOND}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Time> MINUTE;
/**
* Unit of measurement defined as 60×60 seconds (1 h).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #SECOND}
* and the unlocalized name is “hour”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em">{@link #MILLISECOND}, <b>{@link #SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #MINUTE}, <u>{@code HOUR}</u>, {@link #DAY}, {@link #WEEK}, {@link #TROPICAL_YEAR}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #KILOMETRES_PER_HOUR}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Time> HOUR;
/**
* Unit of measurement defined as 24×60×60 seconds (1 d).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #SECOND}
* and the unlocalized name is “day”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em">{@link #MILLISECOND}, <b>{@link #SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #MINUTE}, {@link #HOUR}, <u>{@code DAY}</u>, {@link #WEEK}, {@link #TROPICAL_YEAR}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #KILOMETRES_PER_HOUR}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Time> DAY;
/**
* Unit of measurement defined as 7 days (1 wk).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #SECOND}
* and the unlocalized name is “week”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em">{@link #MILLISECOND}, <b>{@link #SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #MINUTE}, {@link #HOUR}, {@link #DAY}, <u>{@link #WEEK}</u>, {@link #TROPICAL_YEAR}.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #KILOMETRES_PER_HOUR}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Time> WEEK;
/**
* Unit of measurement approximately equals to 365.24219 days (1 a).
* This is defined by the International Union of Geological Sciences (IUGS) as exactly 31556925.445 seconds,
* taken as the length of the tropical year in the the year 2000.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #SECOND},
* the unlocalized name is “year” and the identifier is EPSG:1029.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI time units:</td> <td style="word-spacing:1em">{@link #MILLISECOND}, <b>{@link #SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #MINUTE}, {@link #HOUR}, {@link #DAY}, {@link #WEEK}, <u>{@code TROPICAL_YEAR}</u>.</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #KILOMETRES_PER_HOUR}, {@link #HERTZ}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Time> TROPICAL_YEAR;
/**
* The SI derived unit for frequency (Hz).
* One hertz is equal to one cycle per {@linkplain #SECOND second}.
* The unlocalized name is “hertz”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td><td style="word-spacing:0.5em">{@link #SECOND}<sup>-1</sup></td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Frequency> HERTZ;
/**
* The unit for angular velocity (rad/s).
* The identifier is EPSG:1035.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #RADIAN} ∕ {@link #SECOND}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<AngularVelocity> RADIANS_PER_SECOND;
/**
* The SI derived unit for speed (m/s).
* The unlocalized name is “metres per second” and the identifier is EPSG:1026.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI speed units:</td> <td style="word-spacing:1em"><u><b>{@code METRES_PER_SECOND}</b></u>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #KILOMETRES_PER_HOUR}.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #METRE} ∕ {@link #SECOND}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Speed> METRES_PER_SECOND;
/**
* Unit of measurement defined as 1/3.6 metres per second (1 km/h).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #METRES_PER_SECOND}
* and the unlocalized name is “kilometres per hour”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI speed units:</td> <td style="word-spacing:1em"><b>{@link #METRES_PER_SECOND}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em"><u>{@code KILOMETRES_PER_HOUR}</u>.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #KILOMETRE} ∕ {@link #HOUR}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Speed> KILOMETRES_PER_HOUR;
/**
* The SI derived unit for pressure (Pa).
* One pascal is equal to 1 N/m².
* Pressures are often used in {@linkplain org.apache.sis.referencing.crs.DefaultParametricCRS parametric CRS}
* for height measurements on a vertical axis.
* The unlocalized name is “pascal”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI pressure units:</td> <td style="word-spacing:1em"><u><b>{@code PASCAL}</b></u>, {@link #HECTOPASCAL}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DECIBAR}, {@link #BAR}, {@link #ATMOSPHERE}.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #NEWTON} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Pressure> PASCAL;
/**
* Unit of measurement defined as 100 pascals (1 hPa).
* The hectopascal is the international unit for measuring atmospheric or barometric pressure
* and is exactly equal to one millibar.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #PASCAL}
* and the unlocalized name is “hectopascal”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI pressure units:</td> <td style="word-spacing:1em"><b>{@link #PASCAL}</b>, <u>{@code HECTOPASCAL}</u>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DECIBAR}, {@link #BAR}, {@link #ATMOSPHERE}.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #NEWTON} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Pressure> HECTOPASCAL;
/**
* Unit of measurement defined as 10000 pascals (1 dbar).
* This unit is used in oceanography as there is an approximate numerical equivalence
* between pressure changes in decibars and depth changes in metres underwater.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #PASCAL}
* and the unlocalized name is “decibar”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI pressure units:</td> <td style="word-spacing:1em"><b>{@link #PASCAL}</b>, {@link #HECTOPASCAL}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em"><u>{@code DECIBAR}</u>, {@link #BAR}, {@link #ATMOSPHERE}.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #NEWTON} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Pressure> DECIBAR;
/**
* Unit of measurement defined as 100000 pascals (1 bar).
* One bar is slightly less than the average atmospheric pressure on Earth at sea level.
* One millibar is exactly equal to one {@linkplain #HECTOPASCAL hectopascal}.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #PASCAL}
* and the unlocalized name is “bar”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI pressure units:</td> <td style="word-spacing:1em"><b>{@link #PASCAL}</b>, {@link #HECTOPASCAL}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DECIBAR}, <u>{@code BAR}</u>, {@link #ATMOSPHERE}.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #NEWTON} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Pressure> BAR;
/**
* Unit of measurement defined as 101325 pascals (1 atm).
* One atmosphere reflects the pressure at the mean sea level for countries around 49°N of latitude.
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #PASCAL}
* and the unlocalized name is “atmosphere”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI pressure units:</td> <td style="word-spacing:1em"><b>{@link #PASCAL}</b>, {@link #HECTOPASCAL}.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #DECIBAR}, {@link #BAR}, <u>{@code ATMOSPHERE}</u>.</td></tr>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #NEWTON} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Pressure> ATMOSPHERE;
/**
* The SI derived unit for force (N).
* One newton is the force required to give a mass of 1 kg an acceleration of 1 m/s².
* The unlocalized name is “newton”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #KILOGRAM} ⋅ {@link #METRES_PER_SECOND} ∕ {@link #SECOND}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #PASCAL}, {@link #JOULE}, {@link #WATT}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Force> NEWTON;
/**
* The SI derived unit for energy (J).
* The unlocalized name is “joule”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #NEWTON} ⋅ {@link #METRE}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #WATT}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Energy> JOULE;
/**
* The SI derived unit for power (W).
* One watt is equal to one joule per second.
* The unlocalized name is “watt”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #JOULE} ∕ {@link #SECOND}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #VOLT}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Power> WATT;
/**
* The SI derived unit for electric potential difference (V).
* The unlocalized name is “volt”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #WATT} ∕ {@link #AMPERE}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #FARAD}, {@link #OHM}, {@link #SIEMENS}, {@link #WEBER}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricPotential> VOLT;
/**
* The SI base unit for electric current (A).
* The unlocalized name is “ampere”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #COULOMB}, {@link #VOLT}, {@link #OHM}, {@link #SIEMENS}, {@link #HENRY}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricCurrent> AMPERE;
/**
* The SI derived unit for electric charge (C).
* One coulomb is the charge transfered by a current of one ampere during one second.
* The unlocalized name is “coulomb”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #AMPERE} ⋅ {@link #SECOND}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #FARAD}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricCharge> COULOMB;
/**
* The SI derived unit for electric capacitance (F).
* The unlocalized name is “farad”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #COULOMB} ∕ {@link #VOLT}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricCapacitance> FARAD;
/**
* The SI derived unit for electric resistance (Ω).
* This is the inverse of electric conductance.
* The unlocalized name is “ohm”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #VOLT} ∕ {@link #AMPERE}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #SIEMENS}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricResistance> OHM;
/**
* The SI derived unit for electric conductance (S).
* This is the inverse of electric resistance.
* The unlocalized name is “siemens”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #AMPERE} ∕ {@link #VOLT}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #OHM}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricConductance> SIEMENS;
/**
* The SI derived unit for magnetic flux (Wb).
* The unlocalized name is “weber”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #VOLT} ⋅ {@link #SECOND}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #TESLA}, {@link #HENRY}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<MagneticFlux> WEBER;
/**
* The SI derived unit for magnetic flux density (T).
* The unlocalized name is “tesla”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #WEBER} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<MagneticFluxDensity> TESLA;
/**
* The SI derived unit for inductance (H).
* The unlocalized name is “henry”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #WEBER} ∕ {@link #AMPERE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<ElectricInductance> HENRY;
/**
* The SI base unit for thermodynamic temperature (K).
* The unlocalized name is “kelvin”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI temperature units:</td> <td style="word-spacing:1em"><u><b>{@code KELVIN}</b></u>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #CELSIUS}, {@link #FAHRENHEIT}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Temperature> KELVIN;
/**
* Unit of measurement defined as the temperature in Kelvin minus 273.15.
* The symbol is °C and the unlocalized name is “Celsius”.
* Note that this is the only SI unit with an upper-case letter in its name.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI temperature units:</td> <td style="word-spacing:1em"><b>{@link #KELVIN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em"><u>{@code CELSIUS}</u>, {@link #FAHRENHEIT}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Temperature> CELSIUS;
/**
* Unit of measurement defined as 1.8 degree Celsius plus 32.
* The symbol is °F and the unlocalized name is “Fahrenheit”
* (note the upper-case "F" letter).
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>SI temperature units:</td> <td style="word-spacing:1em"><b>{@link #KELVIN}</b>.</td></tr>
* <tr><td>In other systems:</td> <td style="word-spacing:1em">{@link #CELSIUS}, <u>{@code FAHRENHEIT}</u>.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Temperature> FAHRENHEIT;
/**
* The SI base unit for luminous intensity (cd).
* The unlocalized name is “candela”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #LUMEN}, {@link #LUX}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<LuminousIntensity> CANDELA;
/**
* The SI derived unit for luminous flux (lm).
* The unlocalized name is “lumen”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #CANDELA} ⋅ {@link #STERADIAN}</td></tr>
* <tr><td>Derived units:</td> <td style="word-spacing:1em">{@link #LUX}.</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<LuminousFlux> LUMEN;
/**
* The SI derived unit for illuminance (lx).
* The unlocalized name is “lux”.
*
* <div class="note">
* <table class="compact" style="margin-left:30px; line-height:1.25">
* <caption>Related units</caption>
* <tr><td>Components:</td> <td style="word-spacing:0.5em">{@link #LUX} ∕ {@link #SQUARE_METRE}</td></tr>
* </table></div>
*
* @since 0.8
*/
public static final Unit<Illuminance> LUX;
/**
* A SI conventional unit for mass (g).
* The unlocalized name is “gram”.
*
* @since 0.8
*/
public static final Unit<Mass> GRAM;
/**
* The SI base unit for mass (kg).
* The unlocalized name is “kilogram”.
*
* @since 0.8
*/
public static final Unit<Mass> KILOGRAM;
/**
* The SI base unit for amount of substance (mol).
* The unlocalized name is “mole”.
*
* @since 0.8
*/
public static final Unit<AmountOfSubstance> MOLE;
/**
* The base dimensionless unit for scale measurements.
* The unlocalized name is “unity” and the identifier is EPSG:9201.
* This is the base of all other {@linkplain #isScale(Unit) scale} units:
*
* {@link #PERCENT} (%),
* {@link #PPM} (ppm) and
* {@link #PIXEL} (px)
* among others.
*
* @since 0.8
*/
public static final Unit<Dimensionless> UNITY;
/**
* Dimensionless unit for percentages (%).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #UNITY}
* and the unlocalized name is “percentage”.
*
* @see #UNITY
* @see #PPM
*
* @since 0.8
*/
public static final Unit<Dimensionless> PERCENT;
/**
* Dimensionless unit for parts per million (ppm).
* The {@linkplain ConventionalUnit#getSystemUnit() system unit} is {@link #UNITY},
* the unlocalized name is “parts per million” and the identifier is EPSG:9202.
*
* @see #UNITY
* @see #PERCENT
*
* @since 0.3
*/
public static final Unit<Dimensionless> PPM;
/**
* Sub-division of logarithm of ratio of the measured quantity to a reference quantity (dB).
*
* @since 1.0
*/
public static final Unit<Dimensionless> DECIBEL;
/**
* Salinity measured using PSS-78. While this is a dimensionless measurement, the {@code "psu"} symbol
* is sometime added to PSS-78 measurement. However this is officially discouraged.
*
* @since 0.8
*/
public static final Unit<Salinity> PSU;
/**
* Sigma-level, used in oceanography. This is a way to measure a depth as a fraction of the sea floor depth.
*
* <p>If we make this field public in a future SIS version, we should consider introducing a new quantity type.
* The type to introduce has not yet been determined.</p>
*/
static final Unit<Dimensionless> SIGMA;
/**
* Dimensionless unit for pixels (px).
* The unlocalized name is “pixel”.
* This unity should not be confused with {@link #POINT}, which is approximately equal to 1/72 of inch.
*
* @see #POINT
*/
public static final Unit<Dimensionless> PIXEL;
/**
* Sets to {@code true} by the static initializer after the initialization has been completed.
* This is a safety against unexpected changes in the {@link UnitRegistry#HARD_CODED} map.
*
* <p>We use here a "lazy final initialization" pattern. We rely on the fact that this field is
* initialized to {@code true} only at the end of the following static initializer. All methods
* invoked in the static initializer will see the default value, which is {@code false}, until
* the initializer fully completed. While apparently dangerous, this behavior is actually documented
* in <a href="http://docs.oracle.com/javase/specs/jls/se8/html/jls-12.html#jls-12.4.1">section 12.4.1
* of Java language specification</a>:</p>
*
* <blockquote>The fact that initialization code is unrestricted allows examples to be constructed where
* the value of a class variable can be observed when it still has its initial default value, before its
* initializing expression is evaluated, but such examples are rare in practice. (…snip…) The full power
* of the Java programming language is available in these initializers; programmers must exercise some care.
* This power places an extra burden on code generators, but this burden would arise in any case because
* the Java programming language is concurrent.</blockquote>
*/
static final boolean initialized;
static {
final UnitDimension length = new UnitDimension('L');
final UnitDimension mass = new UnitDimension('M');
final UnitDimension time = new UnitDimension('T');
final UnitDimension current = new UnitDimension('I');
final UnitDimension temperature = new UnitDimension('Θ');
final UnitDimension amount = new UnitDimension('N');
final UnitDimension luminous = new UnitDimension('J');
final UnitDimension frequency = time.pow(-1);
final UnitDimension area = length.pow(2);
final UnitDimension speed = length.divide(time);
final UnitDimension force = mass.multiply(speed).divide(time);
final UnitDimension energy = force.multiply(length);
final UnitDimension power = energy.divide(time);
final UnitDimension charge = current.multiply(time);
final UnitDimension potential = power.divide(current);
final UnitDimension magneticFlux = potential.multiply(time);
final UnitDimension pressure = force.divide(area);
final UnitDimension dimensionless = UnitDimension.NONE;
/*
* Base, derived or alternate units that we need to reuse more than once in this static initializer.
*/
final SystemUnit<Length> m = add(Length.class, Scalar.Length::new, length, "m", (byte) (SI | PREFIXABLE), Constants.EPSG_METRE);
final SystemUnit<Area> m2 = add(Area.class, Scalar.Area::new, area, "m²", (byte) (SI | PREFIXABLE), (short) 0);
final SystemUnit<Volume> m3 = add(Volume.class, Scalar.Volume::new, length.pow(3), "m³", (byte) (SI | PREFIXABLE), (short) 0);
final SystemUnit<Time> s = add(Time.class, Scalar.Time::new, time, "s", (byte) (SI | PREFIXABLE), (short) 1040);
final SystemUnit<Temperature> K = add(Temperature.class, Scalar.Temperature.FACTORY, temperature, "K", (byte) (SI | PREFIXABLE), (short) 0);
final SystemUnit<Speed> mps = add(Speed.class, Scalar.Speed::new, speed, "m∕s", (byte) (SI | PREFIXABLE), (short) 1026);
final SystemUnit<Pressure> Pa = add(Pressure.class, Scalar.Pressure::new, pressure, "Pa", (byte) (SI | PREFIXABLE), (short) 0);
final SystemUnit<Angle> rad = add(Angle.class, Scalar.Angle::new, dimensionless, "rad", (byte) (SI | PREFIXABLE), (short) 9101);
final SystemUnit<Dimensionless> one = add(Dimensionless.class, Scalar.Dimensionless::new, dimensionless, "", SI, (short) 9201);
final SystemUnit<Mass> kg = add(Mass.class, Scalar.Mass::new, mass, "kg", SI, (short) 0);
/*
* All SI prefix to be used below, with additional converters to be used more than once.
*/
final LinearConverter nano = Prefixes.converter('n');
final LinearConverter micro = Prefixes.converter('µ');
final LinearConverter milli = Prefixes.converter('m');
final LinearConverter centi = Prefixes.converter('c');
final LinearConverter hecto = Prefixes.converter('h');
final LinearConverter kilo = Prefixes.converter('k');
final LinearConverter ten4 = LinearConverter.scale(10000, 1);
/*
* All Unit<Angle>.
* 20 is the greatest common denominator between 180 and 200. The intent is to have arguments as small
* as possible in the call to the scale(double, double) method, while keeping the right side integer.
* Staying closer to zero during conversions helo to reduce rounding errors.
*/
rad.related(4);
RADIAN = rad;
GRAD = add(rad, LinearConverter.scale(Math.PI / 20, 200 / 20), "grad", OTHER, (short) 9105);
DEGREE = add(rad, LinearConverter.scale(Math.PI / 20, 180 / 20), "°", ACCEPTED, Constants.EPSG_PARAM_DEGREES);
ARC_MINUTE = add(rad, LinearConverter.scale(Math.PI / 20, 180*60 / 20), "′", ACCEPTED, (short) 9103);
ARC_SECOND = add(rad, LinearConverter.scale(Math.PI / 20, 180*60*60 / 20), "″", ACCEPTED, (short) 9104);
MICRORADIAN = add(rad, micro, "µrad", SI, (short) 9109);
/*
* All Unit<Length>.
*/
m.related(7);
METRE = m;
NANOMETRE = add(m, nano, "nm", SI, (short) 0);
MILLIMETRE = add(m, milli, "mm", SI, (short) 1025);
CENTIMETRE = add(m, centi, "cm", SI, (short) 1033);
KILOMETRE = add(m, kilo, "km", SI, (short) 9036);
NAUTICAL_MILE = add(m, LinearConverter.scale( 1852, 1), "M", OTHER, (short) 9030);
STATUTE_MILE = add(m, LinearConverter.scale(1609344, 100), "mi", IMPERIAL, (short) 9093);
US_SURVEY_FOOT = add(m, LinearConverter.scale( 1200, 3937), "ftUS", OTHER, (short) 9003);
CLARKE_FOOT = add(m, LinearConverter.scale(3047972654d, 1E10), "ftCla", OTHER, (short) 9005);
FOOT = add(m, LinearConverter.scale( 3048, 10000), "ft", IMPERIAL, (short) 9002);
INCH = add(m, LinearConverter.scale( 254, 10000), "in", IMPERIAL, (short) 0);
POINT = add(m, LinearConverter.scale( 996264, 72000000), "pt", OTHER, (short) 0);
/*
* All Unit<Time>.
*/
s.related(5);
SECOND = s;
MILLISECOND = add(s, milli, "ms", SI, (short) 0);
MINUTE = add(s, LinearConverter.scale( 60, 1), "min", ACCEPTED, (short) 0);
HOUR = add(s, LinearConverter.scale( 60*60, 1), "h", ACCEPTED, (short) 0);
DAY = add(s, LinearConverter.scale( 24*60*60, 1), "d", ACCEPTED, (short) 0);
WEEK = add(s, LinearConverter.scale( 7*24*60*60, 1), "wk", OTHER, (short) 0);
TROPICAL_YEAR = add(s, LinearConverter.scale(31556925445.0, 1000), "a", OTHER, (short) 1029);
/*
* All Unit<Speed>, Unit<AngularVelocity> and Unit<ScaleRateOfChange>.
* The 'unityPerSecond' unit is not added to the registry because it is specific to the EPSG database,
* has no clear symbol and is easy to confuse with Hertz. We create that unit only for allowing us to
* create the "ppm/a" units.
*/
final SystemUnit<ScaleRateOfChange> unityPerSecond;
unityPerSecond = new SystemUnit<>(ScaleRateOfChange.class, frequency, null, OTHER, (short) 1036, null);
unityPerSecond.related(1);
mps.related(1);
METRES_PER_SECOND = mps;
KILOMETRES_PER_HOUR = add(mps, LinearConverter.scale(10, 36), "km∕h", ACCEPTED, (short) 0);
RADIANS_PER_SECOND = add(AngularVelocity.class, null, frequency, "rad∕s", SI, (short) 1035);
add(unityPerSecond, LinearConverter.scale(1, 31556925445E6), "ppm∕a", OTHER, (short) 1030);
/*
* All Unit<Pressure>.
*/
Pa.related(3);
PASCAL = Pa;
HECTOPASCAL = add(Pa, hecto, "hPa", SI, (short) 0);
DECIBAR = add(Pa, ten4, "dbar", OTHER, (short) 0);
BAR = add(Pa, LinearConverter.scale(100000, 1), "bar", OTHER, (short) 0);
ATMOSPHERE = add(Pa, LinearConverter.scale(101325, 1), "atm", OTHER, (short) 0);
/*
* All Unit<Temperature>.
*/
K.related(2);
KELVIN = K;
CELSIUS = add(K, LinearConverter.offset( 27315, 100), "°C", SI, (short) 0);
FAHRENHEIT = add(K, new LinearConverter(100, 45967, 180), "°F", OTHER, (short) 0);
/*
* Unit<Volume> and Unit<Mass>. Those units need to be handled in a special way because:
* 1) The base unit of mass is "kg", not "g". This is handled by a hard-coded case in SystemUnit.
* 2) The liter unit is not a SI units, but despite that is commonly used with SI prefixes.
*/
SQUARE_METRE = m2;
CUBIC_METRE = m3;
KILOGRAM = kg;
HECTARE = add(m2, ten4, "ha", ACCEPTED, (short) 0);
LITRE = add(m3, milli, "L", (byte) (ACCEPTED | PREFIXABLE), (short) 0);
GRAM = add(kg, milli, "g", (byte) (ACCEPTED | PREFIXABLE), (short) 0);
/*
* Force, energy, electricity, magnetism and other units.
* Frequency must be defined after angular velocities.
*/
HERTZ = add(Frequency.class, Scalar.Frequency::new, frequency, "Hz", (byte) (SI | PREFIXABLE), (short) 0);
NEWTON = add(Force.class, Scalar.Force::new, force, "N", (byte) (SI | PREFIXABLE), (short) 0);
JOULE = add(Energy.class, Scalar.Energy::new, energy, "J", (byte) (SI | PREFIXABLE), (short) 0);
WATT = add(Power.class, Scalar.Power::new, power, "W", (byte) (SI | PREFIXABLE), (short) 0);
AMPERE = add(ElectricCurrent.class, null, current, "A", (byte) (SI | PREFIXABLE), (short) 0);
COULOMB = add(ElectricCharge.class, null, charge, "C", (byte) (SI | PREFIXABLE), (short) 0);
VOLT = add(ElectricPotential.class, null, potential, "V", (byte) (SI | PREFIXABLE), (short) 0);
FARAD = add(ElectricCapacitance.class, null, charge.divide(potential), "F", (byte) (SI | PREFIXABLE), (short) 0);
SIEMENS = add(ElectricConductance.class, null, current.divide(potential), "S", (byte) (SI | PREFIXABLE), (short) 0);
OHM = add(ElectricResistance.class, null, potential.divide(current), "Ω", (byte) (SI | PREFIXABLE), (short) 0);
WEBER = add(MagneticFlux.class, null, magneticFlux, "Wb", (byte) (SI | PREFIXABLE), (short) 0);
TESLA = add(MagneticFluxDensity.class, null, magneticFlux.divide(area), "T", (byte) (SI | PREFIXABLE), (short) 0);
HENRY = add(ElectricInductance.class, null, magneticFlux.divide(current), "H", (byte) (SI | PREFIXABLE), (short) 0);
LUX = add(Illuminance.class, null, luminous.divide(area), "lx", (byte) (SI | PREFIXABLE), (short) 0);
LUMEN = add(LuminousFlux.class, null, luminous, "lm", (byte) (SI | PREFIXABLE), (short) 0);
CANDELA = add(LuminousIntensity.class, null, luminous, "cd", (byte) (SI | PREFIXABLE), (short) 0); // Must be after Lumen.
MOLE = add(AmountOfSubstance.class, null, amount, "mol", (byte) (SI | PREFIXABLE), (short) 0);
STERADIAN = add(SolidAngle.class, null, dimensionless, "sr", (byte) (SI | PREFIXABLE), (short) 0);
/*
* All Unit<Dimensionless>.
*/
final SystemUnit<Salinity> sal;
ConventionalUnit<Dimensionless> bel;
SIGMA = add(Dimensionless.class, Scalar.Dimensionless::new, dimensionless, "sigma", OTHER, (short) 0);
PIXEL = add(Dimensionless.class, Scalar.Dimensionless::new, dimensionless, "px", OTHER, (short) 0);
sal = add(Salinity.class, null, dimensionless, null, OTHER, (short) 0);
PSU = add(sal, milli, "psu", OTHER, (short) 0);
PERCENT = add(one, centi, "%", OTHER, (short) 0);
PPM = add(one, micro, "ppm", OTHER, (short) 9202);
bel = add(one, PowerOf10.belToOne(), "B", (byte) (ACCEPTED | PREFIXABLE), (short) 0);
DECIBEL = add(bel, Prefixes.converter('d'), "dB", ACCEPTED, (short) 0);
UNITY = UnitRegistry.init(one); // Must be last in order to take precedence over all other units associated to UnitDimension.NONE.
UnitRegistry.alias(UNITY, Short.valueOf((short) 9203));
UnitRegistry.alias(DEGREE, Short.valueOf(Constants.EPSG_AXIS_DEGREES));
UnitRegistry.alias(ARC_MINUTE, "'");
UnitRegistry.alias(ARC_SECOND, "\"");
UnitRegistry.alias(KELVIN, "K"); // Ordinary "K" letter (not the dedicated Unicode character).
UnitRegistry.alias(CELSIUS, "℃");
UnitRegistry.alias(CELSIUS, "Cel");
UnitRegistry.alias(FAHRENHEIT, "℉");
UnitRegistry.alias(GRAD, "gon");
UnitRegistry.alias(HECTARE, "hm²");
UnitRegistry.alias(LITRE, "l");
UnitRegistry.alias(LITRE, "ℓ");
UnitRegistry.alias(UNITY, SystemUnit.ONE);
initialized = true;
}
/**
* Invoked by {@code Units} static class initializer for registering SI base and derived units.
* This method shall be invoked in a single thread by the {@code Units} class initializer only.
*
* @param quantity the type of quantity that uses this unit (should not be null).
* @param factory the factory to use for creating quantities, or {@code null} if none.
* @param dimension the unit dimension.
* @param symbol the unit symbol, or {@code null} if this unit has no specific symbol.
* @param scope {@link UnitRegistry#SI}, {@link UnitRegistry#ACCEPTED}, other constants or 0 if unknown.
* @param epsg the EPSG code, or 0 if this unit has no EPSG code.
*/
private static <Q extends Quantity<Q>> SystemUnit<Q> add(Class<Q> quantity, ScalarFactory<Q> factory,
UnitDimension dimension, String symbol, byte scope, short epsg)
{
return UnitRegistry.init(new SystemUnit<>(quantity, dimension, symbol, scope, epsg, factory));
}
/**
* Invoked by {@code Units} static class initializer for registering SI conventional units.
* This method shall be invoked in a single thread by the {@code Units} class initializer only.
*
* <p>The {@code target} argument should be an instance of {@link SystemUnit}.
* The only exception is for creating the {@link #DECIBEL} unit base on the bel conventional unit.</p>
*
* <p>If the {@code target} unit holds a list of {@linkplain SystemUnit#related() related units}
* (i.e. conventional units that can not be computed easily by appending a SI prefix), then the new
* conventional unit is added to that list of related units. For example "foot" is related to "metre"
* and "degree Celsius" is related to "Kelvin", but "kilometre" is not recorded as related to "metre"
* because this relationship can be inferred automatically without the need of a {@code related} table.
* The unrecorded units are all SI units related to {@code target} by a scale factor without offset.</p>
*/
private static <Q extends Quantity<Q>> ConventionalUnit<Q> add(AbstractUnit<Q> target, UnitConverter toTarget, String symbol, byte scope, short epsg) {
final ConventionalUnit<Q> unit = UnitRegistry.init(new ConventionalUnit<>(target, toTarget, symbol, scope, epsg));
final ConventionalUnit<Q>[] related = target.related();
if (related != null && (unit.scope != UnitRegistry.SI || !toTarget.isLinear())) {
// Search first empty slot. This algorithm is inefficient, but the length of those arrays is small (<= 7).
int i = 0;
while (related[i] != null) i++;
related[i] = unit;
}
return unit;
}
/**
* Returns the system unit for the given dimension, or {@code null} if none.
* Note that this method can not distinguish the different kinds of dimensionless units.
* If the symbol or the quantity type is known, use {@link #get(String)} or {@link #get(Class)} instead.
*
* <p><b>Implementation note:</b> this method must be defined in this {@code Units} class
* in order to force a class initialization before use.</p>
*/
static SystemUnit<?> get(final Dimension dim) {
return (SystemUnit<?>) UnitRegistry.get(dim);
}
/**
* Returns the system unit for the given quantity, or {@code null} if none.
*
* <p><b>Implementation note:</b> this method must be defined in this {@code Units} class
* in order to force a class initialization before use.</p>
*/
@SuppressWarnings("unchecked")
static <Q extends Quantity<Q>> SystemUnit<Q> get(final Class<Q> type) {
return (SystemUnit<Q>) UnitRegistry.get(type);
}
/**
* Returns the system unit for the given symbol, or {@code null} if none.
* This method does not perform any parsing (prefix, exponents, <i>etc</i>).
* It is only for getting one of the pre-defined constants, for example after deserialization.
*
* <p><b>Implementation note:</b> this method must be defined in this {@code Units} class
* in order to force a class initialization before use.</p>
*
* @see Prefixes#getUnit(String)
*/
@SuppressWarnings("unchecked")
static Unit<?> get(final String symbol) {
return (Unit<?>) UnitRegistry.get(symbol);
}
/**
* Do not allows instantiation of this class.
*/
private Units() {
}
/**
* Returns {@code true} if the given unit is a linear unit.
* Linear units are convertible to {@link #DEGREE}.
*
* <p>Angular units are dimensionless, which may be a cause of confusion with other
* dimensionless units like {@link #UNITY} or {@link #PPM}. This method take care
* of differentiating angular units from other dimensionless units.</p>
*
* @param unit the unit to check (may be {@code null}).
* @return {@code true} if the given unit is non-null and angular.
*
* @see #ensureAngular(Unit)
*/
public static boolean isAngular(final Unit<?> unit) {
return (unit != null) && unit.getSystemUnit().equals(RADIAN);
}
/**
* Returns {@code true} if the given unit is a linear unit.
* Linear units are convertible to {@link #METRE}.
*
* @param unit the unit to check (may be {@code null}).
* @return {@code true} if the given unit is non-null and linear.
*
* @see #METRE
* @see #ensureLinear(Unit)
*/
public static boolean isLinear(final Unit<?> unit) {
return (unit != null) && unit.getSystemUnit().equals(METRE);
}
/**
* Returns {@code true} if the given unit is a pressure unit.
* Pressure units are convertible to {@link #PASCAL}.
* Those units are sometime used instead of linear units for altitude measurements.
*
* @param unit the unit to check (may be {@code null}).
* @return {@code true} if the given unit is non-null and a pressure unit.
*/
public static boolean isPressure(final Unit<?> unit) {
return (unit != null) && unit.getSystemUnit().equals(PASCAL);
}
/**
* Returns {@code true} if the given unit is a temporal unit.
* Temporal units are convertible to {@link #SECOND}.
*
* @param unit the unit to check (may be {@code null}).
* @return {@code true} if the given unit is non-null and temporal.
*
* @see #ensureTemporal(Unit)
*/
public static boolean isTemporal(final Unit<?> unit) {
return (unit != null) && unit.getSystemUnit().equals(SECOND);
}
/**
* Returns {@code true} if the given unit is a dimensionless scale unit.
* This include {@link #UNITY} and {@link #PPM}.
*
* @param unit the unit to check (may be {@code null}).
* @return {@code true} if the given unit is non-null and a dimensionless scale.
*
* @see #UNITY
* @see #ensureScale(Unit)
*/
public static boolean isScale(final Unit<?> unit) {
return (unit != null) && unit.getSystemUnit().equals(UNITY);
}
/**
* Makes sure that the specified unit is either null or an angular unit.
* This method is used for argument checks in constructors and setter methods.
*
* @param unit the unit to check, or {@code null} if none.
* @return the given {@code unit} argument, which may be null.
* @throws IllegalArgumentException if {@code unit} is non-null and not an angular unit.
*
* @see #isAngular(Unit)
*/
@SuppressWarnings("unchecked")
public static Unit<Angle> ensureAngular(final Unit<?> unit) throws IllegalArgumentException {
if (unit != null && !isAngular(unit)) {
throw new IllegalArgumentException(Errors.format(Errors.Keys.NonAngularUnit_1, unit));
}
return (Unit<Angle>) unit;
}
/**
* Makes sure that the specified unit is either null or a linear unit.
* This method is used for argument checks in constructors and setter methods.
*
* @param unit the unit to check, or {@code null} if none.
* @return the given {@code unit} argument, which may be null.
* @throws IllegalArgumentException if {@code unit} is non-null and not a linear unit.
*
* @see #isLinear(Unit)
*/
@SuppressWarnings("unchecked")
public static Unit<Length> ensureLinear(final Unit<?> unit) throws IllegalArgumentException {
if (unit != null && !isLinear(unit)) {
throw new IllegalArgumentException(Errors.format(Errors.Keys.NonLinearUnit_1, unit));
}
return (Unit<Length>) unit;
}
/**
* Makes sure that the specified unit is either null or a temporal unit.
* This method is used for argument checks in constructors and setter methods.
*
* @param unit the unit to check, or {@code null} if none.
* @return the given {@code unit} argument, which may be null.
* @throws IllegalArgumentException if {@code unit} is non-null and not a temporal unit.
*
* @see #isTemporal(Unit)
*/
@SuppressWarnings("unchecked")
public static Unit<Time> ensureTemporal(final Unit<?> unit) throws IllegalArgumentException {
if (unit != null && !isTemporal(unit)) {
throw new IllegalArgumentException(Errors.format(Errors.Keys.NonTemporalUnit_1, unit));
}
return (Unit<Time>) unit;
}
/**
* Makes sure that the specified unit is either null or a scale unit.
* This method is used for argument checks in constructors and setter methods.
*
* @param unit the unit to check, or {@code null} if none.
* @return the given {@code unit} argument, which may be null.
* @throws IllegalArgumentException if {@code unit} is non-null and not a scale unit.
*
* @see #isScale(Unit)
*/
@SuppressWarnings("unchecked")
public static Unit<Dimensionless> ensureScale(final Unit<?> unit) throws IllegalArgumentException {
if (unit != null && !isScale(unit)) {
throw new IllegalArgumentException(Errors.format(Errors.Keys.NonScaleUnit_1, unit));
}
return (Unit<Dimensionless>) unit;
}
/**
* Multiplies the given unit by the given ratio. For example multiplying {@link #CENTIMETRE} by 254/100 gives
* {@link #INCH}. Invoking this method is equivalent to invoking <code>{@linkplain Unit#multiply(double)
* Unit.multiply}(numerator / denominator)</code> except that the use of a ration of integer values help
* Apache SIS to improve accuracy when more than one arithmetic operation are chained.
*
* @param <Q> the quantity measured by the unit.
* @param unit the unit to multiply.
* @param numerator the numerator of the multiplication factor.
* @param denominator the denominator of the multiplication factor.
* @return the unit multiplied by the given factor.
*
* @since 0.8
*/
public static <Q extends Quantity<Q>> Unit<Q> multiply(Unit<Q> unit, double numerator, double denominator) {
return unit.transform(LinearConverter.scale(numerator, denominator));
}
/**
* Returns the factor by which to multiply the standard unit in order to get the given unit.
* The "standard" unit is usually the SI unit on which the given unit is based, as given by
* {@link Unit#getSystemUnit()}.
*
* <div class="note"><b>Example:</b>
* if the given unit is {@link #KILOMETRE}, then this method returns 1000 since a measurement in kilometres
* must be multiplied by 1000 in order to give the equivalent measurement in the "standard" units
* (here {@link #METRE}).</div>
*
* If the given unit is {@code null} or if the conversion to the "standard" unit can not be expressed
* by a single multiplication factor, then this method returns {@link Double#NaN}.
*
* @param <Q> the quantity measured by the unit, or {@code null}.
* @param unit the unit for which we want the multiplication factor to standard unit, or {@code null}.
* @return the factor by which to multiply a measurement in the given unit in order to get an equivalent
* measurement in the standard unit, or NaN if the conversion can not be expressed by a scale factor.
*/
public static <Q extends Quantity<Q>> double toStandardUnit(final Unit<Q> unit) {
return AbstractConverter.scale(unit == null ? null : unit.getConverterTo(unit.getSystemUnit()));
}
/**
* Creates a linear converter from the given scale and offset.
*
* @param scale the scale factor, or {@code null} if none (default value of 1).
* @param offset the offset, or {@code null} if none (default value of 0).
* @return a converter for the given scale and offset.
*
* @see org.apache.sis.referencing.operation.transform.MathTransforms#linear(double, double)
*
* @since 1.0
*/
public static UnitConverter converter(final Number scale, final Number offset) {
return LinearConverter.create(scale, offset);
}
/**
* Returns the coefficients of the given converter expressed as a polynomial equation.
* This method returns the first of the following choices that apply:
*
* <ul>
* <li>If the given converter {@linkplain UnitConverter#isIdentity() is identity}, returns an empty array.</li>
* <li>If the given converter shifts the values without scaling them (for example the conversion from Kelvin to
* Celsius degrees), returns an array of length 1 containing only the offset.</li>
* <li>If the given converter scales the values (optionally in addition to shifting them), returns an array of
* length 2 containing the offset and scale factor, in that order.</li>
* </ul>
*
* This method returns {@code null} if it can not get the polynomial equation coefficients from the given converter.
*
* @param converter the converter from which to get the coefficients of the polynomial equation, or {@code null}.
* @return the polynomial equation coefficients (may be any length, including zero), or {@code null} if the given
* converter is {@code null} or if this method can not get the coefficients.
*
* @since 0.8
*/
@SuppressWarnings("fallthrough")
public static Number[] coefficients(final UnitConverter converter) {
if (converter != null) {
if (converter instanceof AbstractConverter) {
return ((AbstractConverter) converter).coefficients();
}
if (converter.isIdentity()) {
return new Number[0];
}
if (converter.isLinear()) {
final double offset = converter.convert(0); // Should be zero as per JSR-363 specification, but we are paranoiac.
final double scale = converter.convert(1) - offset;
final Number[] c = new Number[(scale != 1) ? 2 : (offset != 0) ? 1 : 0];
switch (c.length) {
case 2: c[1] = scale; // Fall through
case 1: c[0] = offset;
case 0: break;
}
return c;
}
}
return null;
}
/**
* Returns the derivative of the given converter at the given value,
* or {@code NaN} if this method can not compute it.
*
* @param converter the converter for which we want the derivative at a given point, or {@code null}.
* @param value the point at which to compute the derivative.
* @return the derivative at the given point, or {@code NaN} if unknown.
*
* @see org.apache.sis.referencing.operation.transform.AbstractMathTransform#derivative(DirectPosition)
*/
public static double derivative(final UnitConverter converter, final double value) {
return AbstractConverter.derivative(converter, value);
}
/**
* Parses the given symbol. Invoking this method is equivalent to invoking
* {@link UnitFormat#parse(CharSequence)} on a shared locale-independent instance.
* This method is capable to handle some symbols found during WKT parsing or in XML files.
* The list of symbols supported by this method is implementation-dependent
* and may change in future SIS versions.
*
* <div class="section">Parsing authority codes</div>
* As a special case, if the given {@code uom} arguments is of the form {@code "EPSG:####"}
* or {@code "urn:ogc:def:uom:EPSG:####"} (ignoring case and whitespaces), then {@code "####"}
* is parsed as an integer and forwarded to the {@link #valueOfEPSG(int)} method.
*
* <div class="section">NetCDF unit symbols</div>
* The attributes in netCDF files often merge the axis direction with the angular unit,
* as in {@code "degrees_east"} or {@code "degrees_north"}. This {@code valueOf} method
* ignores those suffixes and unconditionally returns {@link #DEGREE} for all axis directions.
* In particular, the units for {@code "degrees_west"} and {@code "degrees_east"}
* do <strong>not</strong> have opposite sign.
* It is caller responsibility to handle the direction of axes associated to netCDF units.
*
* @param uom the symbol to parse, or {@code null}.
* @return the parsed symbol, or {@code null} if {@code uom} was null.
* @throws ParserException if the given symbol can not be parsed.
*
* @see UnitFormat#parse(CharSequence)
*/
public static Unit<?> valueOf(String uom) throws ParserException {
return (uom != null) ? UnitFormat.INSTANCE.parse(uom) : null;
}
/**
* Returns a hard-coded unit from an EPSG code. The {@code code} argument given to this method shall
* be a code identifying a record in the {@code "Unit of Measure"} table of the EPSG geodetic dataset.
* If this method does not recognize the given code, then it returns {@code null}.
*
* <p>The list of units recognized by this method is not exhaustive. This method recognizes
* the base units declared in the {@code TARGET_UOM_CODE} column of the above-cited table,
* and some frequently-used units. The list of recognized units may be updated in any future
* version of SIS.</p>
*
* <p>The {@link org.apache.sis.referencing.factory.sql.EPSGDataAccess} class uses this method
* for fetching the base units, and derives automatically other units from the information
* found in the EPSG database. This method is also used by other classes not directly related
* to the EPSG database, like {@link org.apache.sis.referencing.factory.CommonAuthorityFactory}
* which uses EPSG codes for identifying units.</p>
*
* <p>The currently recognized values are:</p>
* <table class="sis">
* <caption>EPSG codes for units</caption>
* <tr>
* <td><table class="compact">
* <caption>Angular units</caption>
* <tr><td style="width: 40px"><b>Code</b></td><td><b>Unit</b></td></tr>
* <tr><td>9101</td><td>radian</td></tr>
* <tr><td>9102</td><td>decimal degree</td></tr>
* <tr><td>9103</td><td>minute</td></tr>
* <tr><td>9104</td><td>second</td></tr>
* <tr><td>9105</td><td>grad</td></tr>
* <tr><td>9107</td><td>degree-minute-second</td></tr>
* <tr><td>9108</td><td>degree-minute-second</td></tr>
* <tr><td>9109</td><td>microradian</td></tr>
* <tr><td>9110</td><td>sexagesimal degree-minute-second</td></tr>
* <tr><td>9111</td><td>sexagesimal degree-minute</td></tr>
* <tr><td>9122</td><td>decimal degree</td></tr>
* </table></td>
* <td class="sep"><table class="compact">
* <caption>Linear units</caption>
* <tr><td style="width: 40px"><b>Code</b></td><td><b>Unit</b></td></tr>
* <tr><td>1025</td><td>millimetre</td></tr>
* <tr><td>1033</td><td>centimetre</td></tr>
* <tr><td>9001</td><td>metre</td></tr>
* <tr><td>9002</td><td>foot</td></tr>
* <tr><td>9003</td><td>US survey foot</td></tr>
* <tr><td>9030</td><td>nautical mile</td></tr>
* <tr><td>9036</td><td>kilometre</td></tr>
* <tr><td>9093</td><td>statute mile</td></tr>
* </table></td>
* <td class="sep"><table class="compact">
* <caption>Time units</caption>
* <tr><td style="width: 40px"><b>Code</b></td><td><b>Unit</b></td></tr>
* <tr><td>1029</td><td>year</td></tr>
* <tr><td>1040</td><td>second</td></tr>
* </table></td>
* <td class="sep"><table class="compact">
* <caption>Scale units</caption>
* <tr><td style="width: 40px"><b>Code</b></td><td><b>Unit</b></td></tr>
* <tr><td>9201</td><td>unity</td></tr>
* <tr><td>9202</td><td>parts per million</td></tr>
* <tr><td>9203</td><td>unity</td></tr>
* </table></td>
* </tr>
* </table>
*
* <div class="note"><b>Note:</b>
* EPSG uses code 9102 (<cite>degree</cite>) for prime meridian and coordinate operation parameters,
* and code 9122 (<cite>degree (supplier to define representation)</cite>) for coordinate system axes.
* But Apache SIS considers those two codes as synonymous.</div>
*
* @param code the EPSG code for a unit of measurement.
* @return the unit, or {@code null} if the code is unrecognized.
*
* @see org.apache.sis.referencing.factory.GeodeticAuthorityFactory#createUnit(String)
*/
public static Unit<?> valueOfEPSG(final int code) {
/*
* The switch for the SexagesimalConverter cases are needed since we did not put those units
* in the UnitRegistry map for reducing a little bit class loading in the common cases where
* those units are not needed. Other cases are redundant with the UnitRegistry check, but we
* add them opportunistically as a shortcut since those units are frequently used.
*/
switch (code) {
case Constants.EPSG_PARAM_DEGREES: // Fall through
case Constants.EPSG_AXIS_DEGREES: return DEGREE;
case Constants.EPSG_METRE: return METRE;
case 9107: // Fall through
case 9108: return SexagesimalConverter.DMS_SCALED;
case 9110: return SexagesimalConverter.DMS;
case 9111: return SexagesimalConverter.DM;
case 9203: // Fall through
case 9201: return UNITY;
default: {
return (code > 0 && code <= Short.MAX_VALUE) ? (Unit<?>) UnitRegistry.get((short) code) : null;
}
}
}
/**
* Returns the EPSG code of the given units, or {@code null} if unknown.
* This method is the converse of {@link #valueOfEPSG(int)}.
*
* <p>The same unit may be represented by different EPSG codes depending on the context:</p>
* <ul>
* <li>EPSG:9102 – <cite>degree</cite> – is used for prime meridian and coordinate operation parameters.</li>
* <li>EPSG:9122 – <cite>degree (supplier to define representation)</cite> – is used for coordinate system axes.</li>
* </ul>
*
* When such choice exists, the code to return is determined by the {@code inAxis} argument,
* which specifies whether the code will be used for axis definition or in other context.
*
* @param unit the unit for which to get the EPSG code.
* @param inAxis {@code true} for a unit used in Coordinate System Axis definition.
* @return the EPSG code of the given units, or {@code null} if unknown.
*
* @see org.apache.sis.referencing.cs.CoordinateSystems#getEpsgCode(Unit, AxisDirection...)
*
* @since 0.4
*/
public static Integer getEpsgCode(Unit<?> unit, final boolean inAxis) {
if (unit != null) {
if (!(unit instanceof AbstractUnit<?>)) {
unit = get(unit.getSymbol());
if (!(unit instanceof AbstractUnit<?>)) {
return null;
}
}
short code = ((AbstractUnit<?>) unit).epsg;
if (code != 0) {
if (inAxis && code == Constants.EPSG_PARAM_DEGREES) {
code = Constants.EPSG_AXIS_DEGREES;
}
return Integer.valueOf(code);
}
}
return null;
}
}