Holds the dimensionless unit ONE.

See Also

Wikipedia: Natural Units - Choosing constants to normalize, Units of Dimension One

Implements javax.measure.Unit.alternate.

Doc from javax.measure.Unit.alternate.

Returns a system unit equivalent to this unscaled standard unit but used in expressions to distinguish between quantities of a different nature but of the same dimensions.

Examples of alternate units:

Parameters

newSymbol:String

the new symbol for the alternate unit.

Returns:Unit<Q>

the alternate unit.

Annotations

@Override

Annotates the specified unit. Annotation does not change the unit semantic. Annotations are often written between curly braces behind units. For example:
Unit PERCENT_VOL = ((AbstractUnit)Units.PERCENT).annotate("vol"); // "%{vol}" Unit KG_TOTAL = ((AbstractUnit)Units.KILOGRAM).annotate("total"); // "kg{total}" Unit RED_BLOOD_CELLS = ((AbstractUnit)Units.ONE).annotate("RBC"); // "{RBC}" Note: Annotation of system units are not considered themselves as system units.

Parameters

annotation:String

the unit annotation.

Returns:Unit<Q>

the annotated unit.

Implements javax.measure.Unit.asType.

Casts this unit to a parameterized unit of specified nature or throw a ClassCastException if the dimension of the specified quantity and this unit's dimension do not match (regardless whether or not the dimensions are independent or not).

Parameters

<T>

Doc from javax.measure.Unit.asType. The type of the quantity measured by the unit.

type:Class<T>

the quantity class identifying the nature of the unit.

Returns:Unit<T>

Doc from javax.measure.Unit.asType.

this unit parameterized with the specified type.

Annotations

@SuppressWarnings:unchecked

@Override

Exceptions

ClassCastException:

if the dimension of this unit is different from the SI dimension of the specified type.

See Also

Units#getUnit(Class)

Implements java.lang.Comparable.compareTo.

Compares this unit to the specified unit. The default implementation compares the name and symbol of both this unit and the specified unit, giving precedence to the symbol.

Parameters

that:Unit<Q>

Doc from java.lang.Comparable.compareTo.

the object to be compared.

Returns:int

a negative integer, zero, or a positive integer as this unit is less than, equal to, or greater than the specified unit.

Annotations

@Override

Implements javax.measure.Unit.divide.

Doc from javax.measure.Unit.divide.

Returns the result of dividing this unit by an approximate divisor. For example:
GRAM = KILOGRAM.divide(1000d);

Parameters

divisor:double

the divisor value.

Returns:Unit<Q>

this unit divided by the specified divisor.

Annotations

@Override

Implements javax.measure.Unit.divide.

Returns the result of dividing this unit by the specified divisor. If the factor is an integer value, the division is exact. For example:

   QUART = GALLON_LIQUID_US.divide(4); // Exact definition.

Parameters

divisor:Number

the divisor value.

Returns:Unit<Q>

this unit divided by the specified divisor.

Annotations

@Override

Implements javax.measure.Unit.divide.

Returns the quotient of this unit with the one specified.

Parameters

that:Unit<?>

the unit divisor.

Returns:Unit<?>

this.multiply(that.inverse())

Annotations

@Override

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

obj:Object

the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

Redeclares javax.measure.Unit.getBaseUnits.

Doc from javax.measure.Unit.getBaseUnits.

Returns the base units and their exponent whose product is this unit, or null if this unit is a base unit (not a product of existing units).

Returns:Map<? extends Unit<?>, Integer>

the base units and their exponent making up this unit.

Annotations

@Override

Implements javax.measure.Unit.getConverterTo.

Doc from javax.measure.Unit.getConverterTo.

Returns a converter of numeric values from this unit to another unit of same type. This method performs the same work as getConverterToAny(Unit) without raising checked exception.

Parameters

that:Unit<Q>

the unit of same type to which to convert the numeric values.

Returns:UnitConverter

the converter from this unit to that unit.

Annotations

@Override

Exceptions

UnconvertibleException:

if a converter cannot be constructed.

Returns a converter of numeric values from this unit to another unit of same type. This method performs the same work as getConverterToAny(Unit) without raising checked exception.

Parameters

that:Unit<Q>

the unit of same type to which to convert the numeric values.

scale:Quantity.Scale

the measurement scale.

Returns:UnitConverter

the converter from this unit to that unit in the given scale.

Annotations

@API

status:EXPERIMENTAL

Exceptions

UnconvertibleException:

if a converter cannot be constructed.

See Also

getConverterToAny(Unit)

Implements javax.measure.Unit.getConverterToAny.

Doc from javax.measure.Unit.getConverterToAny.

Returns a converter from this unit to the specified unit of type unknown. This method can be used when the quantity type of the specified unit is unknown at compile-time or when dimensional analysis allows for conversion between units of different type.

To convert to a unit having the same parameterized type, getConverterTo(Unit) is preferred (no checked exception raised).

Parameters

that:Unit<?>

the unit to which to convert the numeric values.

Returns:UnitConverter

the converter from this unit to that unit.

Annotations

@Override

Exceptions

IncommensurableException:

if this unit is not compatible with that unit.

UnconvertibleException:

if a converter cannot be constructed.

Returns a converter from this unit to the specified unit of type unknown in the given scale. This method can be used when the quantity type of the specified unit is unknown at compile-time or when dimensional analysis allows for conversion between units of different type.

To convert to a unit having the same parameterized type, getConverterTo(Unit, Scale) is preferred (no checked exception raised).

Parameters

that:Unit<?>

the unit to which to convert the numeric values.

scale:Quantity.Scale

the measurement scale.

Returns:UnitConverter

the converter from this unit to that unit using the given scale.

Annotations

@API

status:EXPERIMENTAL

@SuppressWarnings:rawtypes

Exceptions

IncommensurableException:

if this unit is not compatible with that.

UnconvertibleException:

if a converter cannot be constructed.

See Also

getConverterTo(Unit), isCompatible(Unit)

Redeclares javax.measure.Unit.getDimension.

Doc from javax.measure.Unit.getDimension.

Returns the dimension of this unit. Two units u1 and u2 are compatible if and only if u1.getDimension().equals(u2.getDimension()).

Returns:Dimension

the dimension of this unit.

Annotations

@Override

Implements javax.measure.Unit.getName, tech.uom.lib.common.function.Nameable.getName.

Doc from javax.measure.Unit.getName.

Returns the name (if any) of this unit. This method returns null if this unit has no specific name associated with.

Returns:String

this unit name, or null if this unit has not specific name associated with (e.g. product of units).

Implements javax.measure.Unit.getSymbol, tech.uom.lib.common.function.SymbolSupplier.getSymbol.

Doc from javax.measure.Unit.getSymbol.

Returns the symbol (if any) of this unit. This method returns null if this unit has no specific symbol associated with.

Returns:String

this unit symbol, or null if this unit has not specific symbol associated with (e.g. product of units).

Returns the converter from this unit to its unscaled System Unit unit.

Returns:UnitConverter

getConverterTo(this.toSystemUnit())

See Also

toSystemUnit

Implements javax.measure.Unit.getSystemUnit.

Returns the system unit (unscaled SI unit) from which this unit is derived. They can be be used to identify a quantity given the unit. For example:
static boolean isAngularVelocity(AbstractUnit unit) {
  return unit.getSystemUnit().equals(RADIAN.divide(SECOND));
}
assert(REVOLUTION.divide(MINUTE).isAngularVelocity()); // Returns true.

Returns:Unit<Q>

the unscaled metric unit from which this unit is derived.

Annotations

@Override

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object

Annotations

@Override

Implements javax.measure.Unit.inverse.

Returns the inverse of this physical unit.

Returns:Unit<?>

1 / this

Annotations

@Override

Implements javax.measure.Unit.isCompatible.

Indicates if this unit is compatible with the unit specified. To be compatible both units must be physics units having the same fundamental dimension.

Parameters

that:Unit<?>

the other unit.

Returns:boolean

true if this unit and that unit have the same fundamental dimension according to the current dimensional model; false otherwise.

Annotations

@Override

Implements javax.measure.Unit.isEquivalentTo.

Doc from javax.measure.Unit.isEquivalentTo.

Indicates if this unit represents the same quantity than the given unit, ignoring name and symbols. Two units are equivalent if the conversion between them is identity.

Unlike isCompatible(Unit) an equivalence check requires both units to be strictly type-compatible, because it makes no sense to compare e.g. gram and mm for equivalence. By contrast, the compatibility check can works across different quantity types.

Parameters

that:Unit<Q>

the Unit<Q> to be compared with this instance.

Returns:boolean

true if that ≡ this.

Annotations

@Override

Indicates if this unit belongs to the set of coherent SI units (unscaled SI units). The base and coherent derived units of the SI form a coherent set, designated the set of coherent SI units. The word coherent is used here in the following sense: when coherent units are used, equations between the numerical values of quantities take exactly the same form as the equations between the quantities themselves. Thus if only units from a coherent set are used, conversion factors between units are never required.

Returns:boolean

equals(toSystemUnit())

Implements javax.measure.Unit.multiply.

Doc from javax.measure.Unit.multiply.

Returns the result of multiplying this unit by the specified factor. If the factor is an integer value, the multiplication is exact (recommended). For example:
FOOT = METRE.multiply(3048).divide(10000); // Exact definition.
ELECTRON_MASS = KILOGRAM.multiply(9.10938188e-31); // Approximation.

Parameters

factor:Number

the multiplier

Returns:Unit<Q>

this unit scaled by the specified multiplier.

Annotations

@Override

Implements javax.measure.Unit.multiply.

Doc from javax.measure.Unit.multiply.

Returns the result of multiplying this unit by the specified factor. For example:
FOOT = METRE.multiply(3048).divide(10000); // Exact definition.
ELECTRON_MASS = KILOGRAM.multiply(9.10938188e-31); // Approximation.

Parameters

multiplier:double

the multiplier

Returns:Unit<Q>

this unit scaled by the specified multiplier.

Annotations

@Override

Implements javax.measure.Unit.multiply.

Returns the product of this physical unit with the one specified.

Parameters

that:Unit<?>

the physical unit multiplicand.

Returns:Unit<?>

this * that

Returns the abstract unit represented by the specified characters as per default format. Locale-sensitive unit parsing could be handled using LocalUnitFormat in subclasses of AbstractUnit.

Parameters

charSequence:CharSequence

the character sequence to parse.

Returns:Unit<?>

SimpleUnitFormat.getInstance().parse(csq)

Exceptions

MeasurementParseException:

if the specified character sequence cannot be correctly parsed (e.g. not UCUM compliant).

Implements javax.measure.Unit.pow.

Returns a unit equals to this unit raised to an exponent.

Parameters

n:int

the exponent.

Returns:Unit<?>

the result of raising this unit to the exponent.

Annotations

@Override

Implements javax.measure.Unit.prefix, tech.uom.lib.common.function.PrefixOperator.prefix.

Doc from javax.measure.Unit.prefix.

Returns a new unit equal to this unit prefixed by the specified prefix.

Parameters

prefix:Prefix

the prefix to apply on this unit.

Returns:Unit<Q>

the unit with the given prefix applied.

Annotations

@Override

Implements javax.measure.Unit.root.

Returns a unit equals to the given root of this unit.

Parameters

n:int

the root's order.

Returns:Unit<?>

the result of taking the given root of this unit.

Annotations

@Override

Exceptions

ArithmeticException:

if n == 0 or if this operation would result in an unit with a fractional exponent.

Implements javax.measure.Unit.shift.

Doc from javax.measure.Unit.shift.

Returns the result of setting the origin of the scale of measurement to the given value. The returned unit is convertible with all units that are convertible with this unit. For example the following code:
CELSIUS = KELVIN.shift(273.15); creates a new unit where 0°C (the origin of the new unit) is equals to 273.15 K. Converting from the old unit to the new one is equivalent to subtracting the offset to the value in the old unit.

Parameters

offset:Number

the offset added (expressed in this unit).

Returns:Unit<Q>

this unit offset by the specified value.

Annotations

@Override

Implements javax.measure.Unit.shift.

Doc from javax.measure.Unit.shift.

Returns the result of setting the origin of the scale of measurement to the given value. The returned unit is convertible with all units that are convertible with this unit. For example the following code:
CELSIUS = KELVIN.shift(273.15); creates a new unit where 0°C (the origin of the new unit) is equals to 273.15 K. Converting from the old unit to the new one is equivalent to subtracting the offset to the value in the old unit.

Parameters

offset:double

the offset added (expressed in this unit).

Returns:Unit<Q>

this unit offset by the specified value.

Annotations

@Override

Overrides java.lang.Object.toString.

Implements javax.measure.Unit.toString.

Returns the standard representation of this physics unit. The string produced for a given unit is always the same; it is not affected by the locale. It can be used as a canonical string representation for exchanging units, or as a key for a Hashtable, etc. Locale-sensitive unit parsing could be handled using LocalUnitFormat in subclasses of AbstractUnit.

Returns:String

SimpleUnitFormat.getInstance().format(this)

Annotations

@Override

Implements javax.measure.Unit.transform.

Doc from javax.measure.Unit.transform.

Returns the unit derived from this unit using the specified converter. The converter does not need to be linear. For example:

    Unit<Dimensionless> DECIBEL = Unit.ONE.transform(
        new LogConverter(10).inverse().concatenate(
            new RationalConverter(1, 10)));

Parameters

operation:UnitConverter

the converter from the transformed unit to this unit.

Returns:Unit<Q>

the unit after the specified transformation.

Annotations

@Override