Package com.dautelle.physics

Provides support for physical quantities, automatic error calculation (including numeric errors), and dimension-checking done in the form of class-type checking.

See:
Description

Class Summary

Acceleration	This class represents the rate of change of velocity with respect to time.
AmountOfSubstance	This class represents the number of elementary entities (molecules, for example) of a substance.
Angle	This class represents the figure formed by two lines diverging from a common point.
AngularAcceleration	This class represents the rate of change of angular velocity with respect to time.
AngularVelocity	This class represents the rate of change of angular displacement with respect to time.
Area	This class represents the extent of a planar region or of the surface of a solid measured in square units.
CatalyticActivity	This class represents a catalytic activity.
Constants	This class defines fundamental physical constants in their symbolic form.
DataAmount	This class represents a measure of data amount.
DataRate	This class represents the speed of data-transmission.
Duration	This class represents a period of existence or persistence.
ElectricCapacitance	This class represents an electric capacitance.
ElectricCharge	This class represents an electric charge.
ElectricConductance	This class represents an electric conductance.
ElectricCurrent	This class represents the amount of electric charge flowing past a specified circuit point per unit time.
ElectricInductance	This class represents an electric inductance.
ElectricPotential	This class represents an electric potential or electromotive force.
ElectricResistance	This class represents an Electric Resistance.
Energy	This class represents the capacity of a physical system to do work.
Force	This class represents a quantity that tends to produce an acceleration of a body in the direction of its application.
Frequency	This class represents the number of times a specified phenomenon occurs within a specified interval.
Illuminance	This class represents an illuminance.
Length	This class represents the extent of something along its greatest dimension or the extent of space between two objects or places.
LuminousFlux	This class represents a luminous flux.
LuminousIntensity	This class represents the luminous flux density per solid angle as measured in a given direction relative to the emitting source.
MagneticFlux	This class represents a magnetic flux.
MagneticFluxDensity	This class represents a magnetic flux density.
Mass	This class represents the measure of the quantity of matter that a body or an object contains.
Power	This class represents the rate at which work is done.
Pressure	This class represents a force applied uniformly over a surface.
Quantity	This class represents a measurable amount.
Quantity.Factory	This inner-class represents the ObjectFactory producing Quantity instances.
Quantity.Value	This inner class represents a mutable image of an imutable Quantity.
QuantityFormat	This class provides the interface for formatting and parsing quantities.
RadiationDoseAbsorbed	This class represents the amount of energy deposited per unit of mass.
RadiationDoseEffective	This class represents the effective (or "equivalent") dose of radiation received by a human or some other living organism.
RadioactiveActivity	This class represents a radioactive activity.
Scalar	This class represents a dimensionless quantity.
SolidAngle	This class represents the angle formed by three or more planes intersecting at a common point.
Temperature	This class represents the degree of hotness or coldness of a body or an environment.
Torque	This class represents the moment of a force.
Velocity	This class represents a distance traveled divided by the time of travel.
Volume	This class represents the amount of space occupied by a three-dimensional object or region of space, expressed in cubic units.
VolumetricDensity	This class represents a mass per unit volume of a substance under specified conditions of pressure and temperature.

Package com.dautelle.physics Description

Provides support for physical quantities, automatic error calculation (including numeric errors), and dimension-checking done in the form of class-type checking.

1. Physical quantities:

   This package contains more than 40 predefined quantities with specific methods (e.g. Angle.sin(), Scalar.log()) and constants (e.g. Velocity.SPEED_OF_LIGHT, Mass.PROTON, Constants.µ0). The appropriate quantity sub-class is automatically instantiated when needed.

   Quantity classes support derivation, making the framework easily extendable. For example:

   
           // Derives from top Quantity class.
           public class MagneticDipoleMoment extends Quantity {
               private final static Factory FACTORY = new Factory(SI.AMPERE.multiply(SI.METER.pow(2))) {
                   protected Quantity create() {
                      return new MagneticDipoleMoment();
                   }
               };
           }
   
           // Derives from quantities other than the Quantity class.
           public class Altitude extends Length {
               private final static Factory FACTORY = new Factory(SI.METER.alternate("meter_height")) {
                   protected Quantity create() {
                      return new Altitude();
                   }
               };
           };

   Note: Mapping of the predefined quantities occurs automatically when the library is initialized If the framework is extended (e.g. new quantity sub-classes) the application has to make sure that the new classes are initialized to ensure proper unit registration.

2. Error calculations:

   Quantities take into account measurement errors as well as numeric errors. The default QuantityFormat outputs only the decimal digits being exact. For example:

             Length   x = (Length)   Quantity.valueOf(1, SI.METER);
             Velocity v = (Velocity) Quantity.valueOf(0.01, SI.METER.divide(SI.SECOND));
             Duration t = (Duration) Quantity.valueOf(1, SI.MICRO(SI.SECOND));
             for (int i=0; i < 10000000; i++) {
                 x = (Length) x.add(v.multiply(t));
             }
             System.out.println(x);
   
             > 1.10000000 m

   The exact value is guaranteed to be in the range: ]1.09999999 m, 1.10000001 m[. The same calculation using double would have printed

             > 1.099999999392253

   with no idea on the accuracy of this result.

3. Dimension checking:

   The system unit of a quantity determinates its class. For example, Quantity.valueOf("1 µm") and Quantity.valueOf("1.2 ft") return a Length instance (both "µm" and "ft" units are derived from SI.METER).

   Multiple physical models are supported (e.g. Standard, Relativistic, High-Energy, Quantum and Natural). The current model defines the conversions being allowed as well as the default units to output quantities. For example:

           final Quantity x = Length.valueOf(1, NonSI.INCH);
           System.out.println(x); // Default standard model, length are stated in meters.
           LocalContext.enter();
           try {
               RelativisticModel.select(); // Selects the relativistic model.
               System.out.println(x); // Lengths are stated in second.
               Quantity y = x.add(Duration.valueOf("2.3 µs")); // Length and Duration can be added.
               Mass m = Mass.massOf(Quantity.valueOf("12 GeV")); // Energy is compatible with mass (E=mc2)
           } finally {
              LocalContext.exit();
           }
           > 0.02540000000000000 m
           > 8.47252801803306E-11 s

   Custom units for quantity output is allowed. For example:

           Length x = (Length) Quantity.valueOf(123, SI.CENTI(SI.METER));
           Length.showAs(NonSI.INCH); // Context-local.
           System.out.println(x);
   
           > 48.42519685039370 in