javax.measure

Interface UnitConverter

public interface UnitConverter

A converter of numeric values between different units.

Instances of this class are usually obtained through the Unit.getConverterTo(Unit) method.

Since:

1.0

Version:

1.1, March 25, 2018

Author:

Jean-Marie Dautelle, Werner Keil

See Also:

Unit, Wikipedia: Conversion of units

Method Summary

Modifier and Type	Method and Description
UnitConverter	concatenate(UnitConverter converter) Concatenates this converter with another converter.
double	convert(double value) Converts a double value.
java.lang.Number	convert(java.lang.Number value) Converts a Number value.
java.util.List<? extends UnitConverter>	getConversionSteps() Returns the steps of fundamental converters making up this converter or this if the converter is a fundamental converter.
UnitConverter	inverse() Returns the inverse of this converter.
boolean	isIdentity() Indicates if this converter is an identity converter.
boolean	isLinear() Indicates if this converter is linear.

Method Detail

isIdentity

boolean isIdentity()

Indicates if this converter is an identity converter. The identity converter returns its input argument (convert(x) == x).

Returns:

true if this converter is an identity converter.

isLinear

boolean isLinear()

Indicates if this converter is linear. A converter is linear if:

• convert(u + v) == convert(u) + convert(v)
• convert(r * u) == r * convert(u)

For linear converters the following property always hold:

y1 = c1.convert(x1); y2 = c2.convert(x2); assert y1*y2 == c1.concatenate(c2).convert(x1*x2);

Returns:

true if this converter is linear; false otherwise.

inverse

UnitConverter inverse()

Returns the inverse of this converter. If x is a valid value, then x == inverse().convert(convert(x)) to within the accuracy of computer arithmetic.

Returns:

the inverse of this converter.

convert

java.lang.Number convert(java.lang.Number value)

Converts a Number value.

Parameters:

value - the Number value to convert.

Returns:

the Number value after conversion.

convert

double convert(double value)

Converts a double value.

Parameters:

value - the numeric value to convert.

Returns:

the double value after conversion.

concatenate

UnitConverter concatenate(UnitConverter converter)

Concatenates this converter with another converter. The resulting converter is equivalent to first converting by the specified converter (right converter), and then converting by this converter (left converter).

Parameters:

converter - the other converter to concatenate with this converter.

Returns:

the concatenation of this converter with the other converter.

getConversionSteps

java.util.List<? extends UnitConverter> getConversionSteps()

Returns the steps of fundamental converters making up this converter or this if the converter is a fundamental converter.

For example, converter1.getConversionSteps() returns converter1 while converter1.concatenate(converter2).getConversionSteps() returns converter1, converter2.

Returns:

the list of fundamental converters which concatenated make up this converter.