Package org.unitsofmeasurement.quantity

Provides quantitative properties such as mass, time, distance, heat, and angular separation.

See:
Description

Interface Summary

Acceleration	Rate of change of speed with respect to time.
Action	Energy multiplied by a duration (quantity associated to the Planck Constant).
AmountOfSubstance	Number of elementary entities (molecules, for example) of a substance.
Angle	Figure formed by two lines diverging from a common point.
AngularAcceleration	Rate of change of angular speed with respect to time.
AngularSpeed	Rate of change of angular displacement with respect to time.
AngularVelocity	Deprecated. Renamed AngularSpeed, because speed is a scalar value while velocity is a vector.
Area	Extent of a planar region or of the surface of a solid measured in square units.
CatalyticActivity	Catalytic activity.
Dimensionless	Quantity for which all exponents of the dimensions corresponding to the base units are zero.
DynamicViscosity	Dynamic viscosity.
ElectricCapacitance	Electric capacitance.
ElectricCharge	Electric charge.
ElectricConductance	Electric conductance.
ElectricCurrent	Amount of electric charge flowing past a specified circuit point per unit time.
ElectricInductance	Electric inductance.
ElectricPermittivity	How an electric field affects, and is affected, by a dielectric medium.
ElectricPotential	Electric potential or electromotive force.
ElectricResistance	Electric resistance.
Energy	Capacity of a physical system to do work.
Force	Quantity that tends to produce an acceleration of a body in the direction of its application.
Frequency	Number of times a specified phenomenon occurs within a specified interval.
Illuminance	Illuminance.
Information	Measure of information.
InformationRate	Speed of data-transmission.
IonizingRadiation	Quantity of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them.
KinematicViscosity	Diffusion of momentum.
Length	Extent of something along its greatest dimension or the extent of space between two objects or places.
Luminance	Luminous intensity per unit area of light traveling in a given direction.
LuminousFlux	Luminous flux.
LuminousIntensity	Luminous flux density per solid angle as measured in a given direction relative to the emitting source.
MagneticFieldStrength	Magnetic field strength.
MagneticFlux	Magnetic flux.
MagneticFluxDensity	Magnetic flux density.
MagneticPermeability	Degree of magnetization of a material that responds linearly to an applied magnetic field.
MagnetomotiveForce	Force that produces magnetic flux.
Mass	Measure of the quantity of matter that a body or an object contains.
MassFlowRate	Movement of mass per time.
Power	Rate at which work is done.
Pressure	Force applied uniformly over a surface.
Quantity<Q extends Quantity<Q>>	Property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a unit (adapted from VIM).
RadiationDoseAbsorbed	Amount of energy deposited per unit of mass.
RadiationDoseEffective	Effective (or "equivalent") dose of radiation received by a human or some other living organism.
RadioactiveActivity	Deprecated. Renamed Radioactivity.
Radioactivity	Radioactive activity.
SolidAngle	Angle formed by three or more planes intersecting at a common point.
Speed	Distance traveled divided by the time of travel.
Temperature	Degree of hotness or coldness of a body or an environment.
Time	Period of existence or persistence.
Torque	Moment of a force.
Velocity	Deprecated. Renamed Speed, because speed is a scalar value while velocity is a vector.
Volume	Amount of space occupied by a three-dimensional object or region of space.
VolumetricDensity	Mass per unit volume of a substance under specified conditions of pressure and temperature.
VolumetricFlowRate	Volume of fluid passing a point in a system per unit of time.
WaveNumber	This interface represents a wave property inversely related to wavelength.

Package org.unitsofmeasurement.quantity Description

Provides quantitative properties such as mass, time, distance, heat, and angular separation. Quantities of different kinds are represented by sub-types of the Quantity interface. This package provides sub-types for the quantities defined in the International System of Units (SI), together with a few non-SI quantities. Users can create their own quantity types by extending the Quantity interface.

This package supports measurable quantities, which can be expressed as (Number, Unit) tuples. Those tuples are not expected to be used directly in numerically intensive code. They are more useful as metadata converted to the application internal representation (for example double primitive type with the requirement to provide values in metres) before computation begins.

Quantities sub-types are also used as parameterized type to characterize generic classes and provide additional compile time check. This technic is used extensively by the Unit interface, but users can apply the same approach to their own classes. In the example below, Sensor and Vector3D are user-defined classes:

    // A general-purpose Sensor class used for temperature measurements:
    Sensor<Temperature> sensor ...;
    Temperature temp = sensor.getValue();

    // Velocity vector (a vector of speeds) in a three-dimensional space.
    Unit<Speed> = metrePerSecond = METRE.divide(SECOND);
    Vector3D<Speed> aircraftSpeed = new Vector3D(200.0, 50.0, -0.5, metrePerSecond);
 

Definition of terms
This package adopts the definitions provided by the International vocabulary of metrology, with some adaptations:

• Quantity: property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a unit.
• Kind of quantity: aspect common to mutually comparable quantities.

Since:

0.6.0

Author:

Jean-Marie Dautelle, Werner Keil

See Also:

Quantity, International vocabulary of metrology