pedro-borges / unified-world-units

A generic library of world units.

units

A generic library of world units for type-safe calculation of amounts.

Work in progress since Oct 2017. Fully functional but not ready for use in production.

Use at own risk, contribute at own heart.

Quick example:

Length distance = new Meters(10, Magnitude.KILO);
Time duration = new Hours(2);
Speed speed = distance.div(duration, MathContext.UNLIMITED);
Pace pace = duration.div(distance, MathContext.UNLIMITED);

System.out.println(speed.getAmount() + " " + speed.getUnit());
System.out.println(pace.getAmount() + " " + pace.getUnit());

5000 h⁻¹⋅m

0.0002 h⋅m⁻¹

Soon to be:

 Length distance = new Meters(10, Magnitude.KILO);
 Time duration = new Hours(2);
 Speed speed = distance.div(duration);
 Pace pace = duration.div(distance);
 
 System.out.println(speed.getAmount(MathContext.UNLIMITED) + " " + speed.getUnit());
 System.out.println(pace.getAmount(MathContext.UNLIMITED) + " " + pace.getUnit());

unified-world-units's Issues

Drop funky Magnitude calculation from the core

Guru: Because 1m² = 10dm² is true, if you read "ten deci squaremeters" instead of "ten square decimeters" little grasshopper

Add ElectricPotential

spark spark!

Add UnitAmount.invert()

Things also make sense upside down.

Add Power

With a bang!

Use Magnitudes

Add ElectricalCapacitance

Things don't get much more boring than "electrical capacitance"

Add ElectricCharge

Can't drive a Tesla without it

Create Area and Volume units

Add MagneticField

Extract common code to AbstractUnitAmount

Add java-doc to interfaces and inherit on implementing classes

Add BigDecimal Amount.getValue(Label)

Make amounts generic again

• Make Amount a generic interface for algebraic calculations
• Move back Amount implementation to BigDecimalAmount

Implement Lumen

Let there be light

Add constructors for BigDecimal, Number and String to unidimensional unit amounts

Create frequencyUnit

Interest rate is no more than a frequency, but it's entitled it's name.

Make UnitAmount extend Comparable

Add Scalar unit

Explode generic Space interface to specific Length, Area and Volume

Allow construct of Time units from java.time.Duration

Java has some units after all

Create the Label enum to index elements on multi-dimensional amounts

Create InterestRate UnitAmount

Turn concrete units into singletons

Add ElectricalInductance

Implement base si units

Add Pressure

But do it smoothly

Create ComposedUnit that implements Unit

Make use of the ObjectCounter to track the order of individual units in a formula.

For example:

speed = space / time:
ObjectCounter {
    space = +1
    time = -1
}

acceleration = space / time^2:
ObjectCounter {
    space = +1
    time = -2
}

Devise a way to work with scaled composite units

So we can actually create LITRE or NEWTON units, absolutely necessary to estimate the drinking skills of Mr. Isaac

Add MagneticFlux

Webber was not the inventor of the web.

Create class to manage composed unit magnitudes

Add BigDecimal Amount.getValue()

Add Energy

And then there was light! oh wait that's a different ticket

Add ElectricResistance

It's no use resisting this

Separate into two projects, core and concrete

Divide & conquer said Julius Caesar (or some other famous very old guy)

Implement Gray

But give it a little colour

Force BigDecimalAmount on uni-dimensional units

Of course :)

Fix algebra between composite unit amounts

Bugs are not fun

Make ComposedUnit.operatorByAmount() protected

Booooooring!

Store values in multi-dimensions as an array

Make BaseUnit extend Comparable

This is no joke, really, for example by convention mass supersedes length: 1N = 1Kgm/s² and not 1Kmg/s²

Create Speed composed unit

Add ElectricConductance

Add CurrencyConversion capability

Can I pay in BitCoin?

Create MitchGoesRunningTest

Add pace unit

on the double!

Implement Becquerel

Sounds weird but it's just a concrete type of Frequency (same as Hertz)

Implement abstract composition

The api should allow the user to navigate between unnamed composite units, just because meter * second * volt doesn't make apparent sense that doesn't make it less a unit.

Infer types to allow CompositeUnitAmount.divideBy(UnitAmount)

Need to get the corresponding unit in order to compute the result, what good is to multiply if you can't divide?

Implement Lux

Great club in Lisbon, everyone should visit Lux!

Implement BigDecimal2DAmount and BigDecimal3DAmount