tech.units.indriya.unit (Units of Measurement Reference Implementation 2.1.2 API)

Class Summary
Class	Description
AlternateUnit<Q extends javax.measure.Quantity<Q>>	This class represents units used in expressions to distinguish between quantities of a different nature but of the same dimensions.
AnnotatedUnit<Q extends javax.measure.Quantity<Q>>	This class represents an annotated unit.
BaseUnit<Q extends javax.measure.Quantity<Q>>	This class represents the building blocks on top of which all others physical units are created.
DefaultSystemOfUnitsService
ProductUnit<Q extends javax.measure.Quantity<Q>>	This class represents units formed by the product of rational powers of existing physical units.
TransformedUnit<Q extends javax.measure.Quantity<Q>>	This class represents the units derived from other units using converters.
UnitDimension	This class represents a dimension of a unit of measurement.
Units	This class defines common units.

Package tech.units.indriya.unit Description

This package provides supports for physics units, in conformity with the Units of Measurement API.

Usage:



 import javax.measure.quantity.*; // Holds quantity types.
 
 import tech.units.indriya.AbstractUnit;
 import tech.units.indriya.function.AbstractConverter;
 
 import static tech.units.indriya.unit.Units.*; // Standard units.
 import static javax.measure.MetricPrefix.*;
 import ...US.*; // US units (external module)
 
 public class Main {
     public void main(String[] args) {

         // Conversion between units (explicit way).
         AbstractUnit sourceUnit = KILO(METRE);
         AbstractUnit targetUnit = MILE;
         PhysicsConverter uc = sourceUnit.getConverterTo(targetUnit);
         System.out.println(uc.convert(10)); // Converts 10 km to miles.

         // Same conversion than above, packed in one line.
         System.out.println(KILO(METRE).getConverterTo(MILE).convert(10));

         // Retrieval of the SI unit (identifies the measurement type).
         System.out.println(REVOLUTION.divide(MINUTE).toSystemUnit());

         // Dimension checking (allows/disallows conversions)
         System.out.println(ELECTRON_VOLT.isCompatible(WATT.times(HOUR)));

         // Retrieval of the unit dimension (depends upon the current model).
         System.out.println(ELECTRON_VOLT.getDimension());
     }
 }

 > 6.2137119223733395
 > 6.2137119223733395
 > rad/s
 > true
 > [L]²·[M]/[T]²

Unit Parameterization

CommonUnits are parameterized enforce compile-time checks of units/measures consistency, for example:



     Unit MINUTE = SECOND.times(60); // Ok.
     tUnit MINUTE = METRE.times(60); // Compile error.

     Unit HECTOPASCAL = HECTO(PASCAL); // Ok.
     Unit HECTOPASCAL = HECTO(NEWTON); // Compile error.

     Quantity duration = ComparableQuantity.of(2, MINUTE); // Ok.
     Quantity duration = ComparableQuantity.of(2, CELSIUS); // Compile error.

     long milliseconds = duration.longValue(MILLI(SECOND)); // Ok.
     long milliseconds = duration.longValue(POUND); // Compile error.

Runtime checks of dimension consistency can be done for more complex cases.


     Unit SQUARE_METRE = METRE.times(METRE).asType(Area.class); // Ok.
     Unit SQUARE_METRE = METRE.times(KELVIN).asType(Area.class); // Runtime error.

     Unit KELVIN = AbstractUnit.of("K").asType(Temperature.class); // Ok.
     Unit KELVIN = AbstractUnit.of("kg").asType(Temperature.class); // Runtime error.

Version:: 2.0
Author:: Jean-Marie Dautelle, Werner Keil