javax.measure

Interface Measurable<Q extends Quantity>

All Superinterfaces:

java.lang.Comparable<Measurable<Q>>

All Known Implementing Classes:

DecimalMeasure, Measure, VectorMeasure

public interface Measurable<Q extends Quantity>
extends java.lang.Comparable<Measurable<Q>>

This interface represents the measurable, countable, or comparable property or aspect of a thing. Implementing instances are typically the result of a measurement:

 Measurable<Mass> weight = Measure.valueOf(180.0, POUND);
 

They can also be created from custom classes:

 class Delay implements Measurable<Duration> {
     private long nanoSeconds; // Implicit internal unit.
     public double doubleValue(Unit<Velocity> unit) { ... }
     public long longValue(Unit<Velocity> unit) { ... }
 }
 
 Thread.wait(new Delay(24, HOUR)); // Assuming Thread.wait(Measurable<Duration>) method.
 

Although measurable instances are for the most part scalar quantities; more complex implementations (e.g. vectors, data set) are allowed as long as an aggregate magnitude can be determined. For example:

 class Velocity3D implements Measurable<Velocity> {
     private double x, y, z; // Meter per seconds.
     public double doubleValue(Unit<Velocity> unit) { ... } // Returns vector norm.
     ...
 }
 
 class Sensors<Q extends Quantity> extends Measure<double[], Q> {
     public doubleValue(Unit<Q> unit) { ... } // Returns median value.
     ...
 }
 

Method Summary

Methods

Modifier and Type	Method and Description
Measurable<Q>	add(Measurable<Q> other) Adds the other Measurable to this one, returning a Measurable object of the same type as the original.
double	doubleValue(Unit<Q> unit) Returns the value of this measurable stated in the specified unit as a double.
long	longValue(Unit<Q> unit) Returns the estimated integral value of this measurable stated in the specified unit as a long.

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

doubleValue

double doubleValue(Unit<Q> unit)

Returns the value of this measurable stated in the specified unit as a double. If the measurable has too great a magnitude to be represented as a double, it will be converted to Double.NEGATIVE_INFINITY or Double.POSITIVE_INFINITY as appropriate.

Parameters:

unit - the unit in which this measurable value is stated.

Returns:

the numeric value after conversion to type double.

longValue

long longValue(Unit<Q> unit)
               throws java.lang.ArithmeticException

Returns the estimated integral value of this measurable stated in the specified unit as a long.

Note: This method differs from the Number.longValue() in the sense that the closest integer value is returned and an ArithmeticException is raised instead of a bit truncation in case of overflow (safety critical).

Parameters:

unit - the unit in which the measurable value is stated.

Returns:

the numeric value after conversion to type long.

Throws:

java.lang.ArithmeticException - if this quantity cannot be represented as a long number in the specified unit.

add

Measurable<Q> add(Measurable<Q> other)

Adds the other Measurable to this one, returning a Measurable object of the same type as the original.

Parameters:

other - The measurable that should be added to this one.

Returns:

A new measurable that contains the summed up value of this and the other one.