Package org.apache.sis.measure

package org.apache.sis.measure
Units of measurements, values related to measurement (like angles and ranges) and their formatters. A key class in this package is Units, which provides static constants for about 50 units of measurement including all the SI base units (metre, kilogram second, ampere, kelvin, mole and candela) together with some derived units (square metre, cubic metre, metres per second, hertz, pascal, newton, joule, watt, tesla, etc.) and some dimensionless units (radian, steradian, pixel, unity). In relation to units of measurement, this package also defines: Apache SIS supports arithmetic operations on units and on quantities. The unit (including SI prefix) and the quantity type resulting from those arithmetic operations are automatically inferred. For example this line of code:
System.out.println( Units.PASCAL.multiply(1000) );
prints "kPa", i.e. the kilo prefix has been automatically applied (SI prefixes are applied on SI units only, not on other systems). Other example:
Force  f = Quantities.create(4, Units.NEWTON);
Length d = Quantities.create(6, Units.MILLIMETRE);
Time   t = Quantities.create(3, Units.SECOND);
Quantity<?> e = f.multiply(d).divide(t);
System.out.println("Instance of Power: " + (e instanceof Power));
prints "8 mW" and "Instance of Power: true", i.e. Apache SIS detects that the result of N⋅m∕s is Watt, inherits the milli prefix from millimetre and creates an instance of Power, not just Quantity<Power> (the generic parent).

Parsing and formatting use Unicode symbols by default, as in µg/m². Parenthesis are recognized at parsing time and used for denominators at formatting time, as in kg/(m²⋅s). While uncommon, Apache SIS accepts fractional powers as in m^⅔. Some sentences like "100 feet", "square metre" and "degree Kelvin" are also recognized at parsing time.


Defined in the sis-utility module