visad
Class OffsetUnit

java.lang.Object
  visad.Unit
      visad.OffsetUnit

All Implemented Interfaces:

Serializable

public final class OffsetUnit
extends Unit
implements Serializable

A class that represents a scaled unit with an offset. Instances are immutable.

Author:

Steven R. Emmerson This is part of Steve Emerson's Unit package that has been incorporated into VisAD. Instances are immutable.

See Also:

Serialized Form

Field Summary

Fields inherited from class visad.Unit

hashCode

Constructor Summary

OffsetUnit(double offset)
Construct an offset, dimensionless unit.

OffsetUnit(double offset, String identifier)
Construct an offset, dimensionless unit with an identifier.

OffsetUnit(double offset, Unit unit)
Construct an offset unit from another unit.

OffsetUnit(double offset, Unit unit, String identifier)
Construct an offset unit from another unit and an identifier.

Method Summary

Unit	divide(Unit that) Divide an offset unit by another unit.
protected Unit	divideInto(Unit that) Divide an offset unit into another unit.
boolean	equals(Unit unit) Indicates if this instance equals a unit.
Unit	getAbsoluteUnit() Gets the absolute unit of this unit.
String	getDefinition() Return the definition of this unit.
DerivedUnit	getDerivedUnit() Returns the derived unit that underlies this unit.
int	hashCode() Returns the hash code of this instance.
boolean	isConvertible(Unit unit) Indicate whether this unit is convertible with another unit.
boolean	isDimensionless() Indicates if this instance is dimensionless.
protected boolean	isTime() Indicates if this instance is a unit of time.
Unit	log(double base) Returns the logarithmic unit that has this unit as its reference level.
static void	main(String[] args) Test this class.
Unit	multiply(Unit that) Multiply an offset unit by another unit.
Unit	pow(double power) Raises an offset unit to a power.
Unit	pow(int power) Raises an offset unit to a power.
protected Unit	protectedClone(String identifier) Clones this unit, changing the identifier.
Unit	root(int root) Returns the N-th root of this unit.
Unit	scale(double amount) Scale this unit by an amount.
Unit	shift(double offset) Shift this unit by an amount.
double[]	toThat(double[] values, Unit that) Convert values from this unit to another unit.
double[]	toThat(double[] values, Unit that, boolean copy) Convert values from this unit to another unit.
float[]	toThat(float[] values, Unit that) Convert values from this unit to another unit.
float[]	toThat(float[] values, Unit that, boolean copy) Convert values from this unit to another unit.
double[]	toThis(double[] values, Unit that) Convert values to this unit from another unit.
double[]	toThis(double[] values, Unit that, boolean copy) Convert values to this unit from another unit.
float[]	toThis(float[] values, Unit that) Convert values to this unit from another unit.
float[]	toThis(float[] values, Unit that, boolean copy) Convert values to this unit from another unit.

Methods inherited from class visad.Unit

adjustCheckAndCache, canConvert, canConvertArray, clone, convertTuple, convertTuple, convertTuple, convertTuple, copyUnitsArray, equals, getIdentifier, sqrt, toString, toThat, toThis, transformUnits, transformUnits, transformUnits, transformUnits

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

OffsetUnit

public OffsetUnit(double offset)

Construct an offset, dimensionless unit. The identifier will be empty.

Parameters:

offset - The amount of offset.

OffsetUnit

public OffsetUnit(double offset,
                  String identifier)

Construct an offset, dimensionless unit with an identifier.

Parameters:

offset - The amount of offset.

identifier - The name or abbreviation for the cloned unit. May be null or empty.

OffsetUnit

public OffsetUnit(double offset,
                  Unit unit)

Construct an offset unit from another unit. The identifier will be that of the base unit if the offset is zero; otherwise, the identifier will be null.

Parameters:

offset - The amount of offset.

unit - The other unit.

OffsetUnit

public OffsetUnit(double offset,
                  Unit unit,
                  String identifier)

Construct an offset unit from another unit and an identifier.

Parameters:

offset - The amount of offset.

unit - The other unit.

identifier - The name or abbreviation for the cloned unit. May be null or empty.

Method Detail

isDimensionless

public boolean isDimensionless()

Indicates if this instance is dimensionless. A unit is dimensionless if it is a measure of a dimensionless quantity like angle or concentration. Examples of dimensionless units include radian, degree, steradian, and "g/kg".

Specified by:

isDimensionless in class Unit

Returns:

True if an only if this unit is dimensionless.

isTime

protected boolean isTime()

Indicates if this instance is a unit of time.

Returns:

true if and only if this instance is a unit of time.

protectedClone

protected Unit protectedClone(String identifier)

Clones this unit, changing the identifier.

Specified by:

protectedClone in class Unit

Parameters:

identifier - The name or abbreviation for the cloned unit. May be null or empty.

Returns:

A unit equal to this unit but with the given identifier.

scale

public Unit scale(double amount)
           throws UnitException

Description copied from class: Unit

Scale this unit by an amount.

Specified by:

scale in class Unit

Parameters:

amount - The amount by which to scale this unit. E.g. Unit yard = meter.scale(0.9144);

Returns:

A unit equal to this instance scaled by the given amount.

Throws:

UnitException - This unit cannot be scaled.

shift

public Unit shift(double offset)
           throws UnitException

Description copied from class: Unit

Shift this unit by an amount.

Specified by:

shift in class Unit

Parameters:

offset - The amount by which to shift this unit. E.g. Unit celsius = kelvin.shift(273.15);

Returns:

A unit equal to this instance with the origin shifted by the given amount.

Throws:

UnitException - The unit subclass is unknown.

log

public Unit log(double base)
         throws UnitException

Description copied from class: Unit

Returns the logarithmic unit that has this unit as its reference level. Not all units can be used as a reference level.

Specified by:

log in class Unit

Parameters:

base - The logarithmic base: one of 2, Math.E, or 10.

Returns:

The logarithmic unit that has this instance as its reference level.

Throws:

UnitException - if this unit can't be used as a reference level for a logarithmic unit.

pow

public Unit pow(int power)
         throws UnitException

Raises an offset unit to a power. Raising an offset unit to a power is equivalent to first stripping-off the offset amount and then raising the resulting non-offset unit to the power.

Specified by:

pow in class Unit

Parameters:

power - The power to raise this unit by.

Returns:

A corresponding unit.

Throws:

UnitException - if the underlying unit can't be raised to the given power.

pow

public Unit pow(double power)
         throws UnitException

Raises an offset unit to a power. Raising an offset unit to a power is equivalent to first stripping-off the offset amount and then raising the resulting non-offset unit to the power.

Specified by:

pow in class Unit

Parameters:

power - The power to raise this unit by.

Returns:

A corresponding unit.

Throws:

UnitException - if the underlying unit can't be raised to the given power.

root

public Unit root(int root)
          throws IllegalArgumentException,
                 UnitException

Returns the N-th root of this unit. Taking the root of an offset unit is equivalent to first stripping-off the offset amount and then taking the root of the resulting non-offset unit.

Specified by:

root in class Unit

Parameters:

root - The root to take (e.g. 2 means square root). May not be zero.

Returns:

The unit corresponding to the root-th root of this unit.

Throws:

IllegalArgumentException - The root value is zero or the resulting unit would have a non-integral unit dimension.

UnitException - if the underlying unit can't have the given root taken.

getDefinition

public String getDefinition()

Return the definition of this unit.

Specified by:

getDefinition in class Unit

Returns:

The definition of this unit (e.g. "K @ 273.15" for degree celsius).

multiply

public Unit multiply(Unit that)
              throws UnitException

Multiply an offset unit by another unit.

Specified by:

multiply in class Unit

Parameters:

that - The unit with which to multiply this unit.

Returns:

A unit equal to this instance multiplied by the given unit.

Throws:

UnitException - Can't multiply units.

divide

public Unit divide(Unit that)
            throws UnitException

Divide an offset unit by another unit.

Specified by:

divide in class Unit

Parameters:

that - The unit to divide into this unit.

Returns:

A unit equal to this instance divided by the given unit.

Throws:

UnitException - Can't divide units.

divideInto

protected Unit divideInto(Unit that)
                   throws UnitException

Divide an offset unit into another unit.

Specified by:

divideInto in class Unit

Parameters:

that - The unit to be divide by this unit.

Returns:

The quotient of the two units. promise: Neither unit has been modified.

Throws:

UnitException - Meaningless operation.

toThis

public double[] toThis(double[] values,
                       Unit that)
                throws UnitException

Convert values to this unit from another unit.

Specified by:

toThis in class Unit

Parameters:

values - The values to be converted.

that - The unit of values.

Returns:

The converted values in units of this unit. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThis

public float[] toThis(float[] values,
                      Unit that)
               throws UnitException

Convert values to this unit from another unit.

Specified by:

toThis in class Unit

Parameters:

values - The values to be converted.

that - The unit of values.

Returns:

The converted values in units of this unit. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThis

public double[] toThis(double[] values,
                       Unit that,
                       boolean copy)
                throws UnitException

Convert values to this unit from another unit.

Overrides:

toThis in class Unit

Parameters:

values - The values to be converted.

that - The unit of values.

copy - if false and that equals this, return values, else return a new array

Returns:

The converted values in units of this unit. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThis

public float[] toThis(float[] values,
                      Unit that,
                      boolean copy)
               throws UnitException

Convert values to this unit from another unit.

Overrides:

toThis in class Unit

Parameters:

values - The values to be converted.

that - The unit of values.

copy - if false, convert values in place.

Returns:

The converted values in units of this unit. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThat

public double[] toThat(double[] values,
                       Unit that)
                throws UnitException

Convert values from this unit to another unit.

Specified by:

toThat in class Unit

Parameters:

values - The values to be converted in units of this unit.

that - The unit to which to convert the values.

Returns:

The converted values. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThat

public float[] toThat(float[] values,
                      Unit that)
               throws UnitException

Convert values from this unit to another unit.

Specified by:

toThat in class Unit

Parameters:

values - The values to be converted in units of this unit.

that - The unit to which to convert the values.

Returns:

The converted values. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThat

public double[] toThat(double[] values,
                       Unit that,
                       boolean copy)
                throws UnitException

Convert values from this unit to another unit.

Overrides:

toThat in class Unit

Parameters:

values - The values to be converted in units of this unit.

that - The unit to which to convert the values.

copy - if false and that equals this, return a values, else return a new array

Returns:

The converted values. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

toThat

public float[] toThat(float[] values,
                      Unit that,
                      boolean copy)
               throws UnitException

Convert values from this unit to another unit.

Overrides:

toThat in class Unit

Parameters:

values - The values to be converted in units of this unit.

that - The unit to which to convert the values.

copy - if false and that equals this, return a values, else return a new array

Returns:

The converted values. require: The units are convertible. promise: Neither unit has been modified.

Throws:

UnitException - The units are not convertible.

getAbsoluteUnit

public Unit getAbsoluteUnit()

Gets the absolute unit of this unit. An interval in the underlying physical quantity has the same numeric value in an absolute unit of a unit as in the unit itself -- but an absolute unit is always referenced to the physical origin of the underlying physical quantity. For example, the absolute unit corresponding to degrees celsius is degrees kelvin -- and calling this method on a degrees celsius unit obtains a degrees kelvin unit.

Overrides:

getAbsoluteUnit in class Unit

Returns:

The absolute unit corresponding to this unit.

isConvertible

public boolean isConvertible(Unit unit)

Indicate whether this unit is convertible with another unit. If one unit is convertible with another, then the toThis(...)/ and toThat(...) methods will not throw a UnitException. Unit A is convertible with unit B if and only if unit B is convertible with unit A; hence, calling-order is irrelevant.

Specified by:

isConvertible in class Unit

Parameters:

unit - The other unit.

Returns:

True if and only if this unit is convertible with the other unit.

main

public static void main(String[] args)
                 throws UnitException

Test this class.

Parameters:

args - Arguments (ignored).

Throws:

UnitException - A problem occurred.

equals

public boolean equals(Unit unit)

Indicates if this instance equals a unit.

Specified by:

equals in class Unit

Parameters:

unit - The unit.

Returns:

true if and only if this instance equals the unit.

hashCode

public int hashCode()

Returns the hash code of this instance. Object.hashCode() should be overridden whenever Object.equals(Object) is.

Specified by:

hashCode in class Unit

Returns:

The hash code of this instance (includes the values).

getDerivedUnit

public DerivedUnit getDerivedUnit()

Description copied from class: Unit

Returns the derived unit that underlies this unit.

Specified by:

getDerivedUnit in class Unit

Returns:

The derived unit that underlies this unit.