SIUnitsArithmetic 1.3.4

SI Units library for dimensional arithmetic

SIUnitsArithmetic defines metric system units and provides related arithmetic operations including unit to unit multiplication even with derived units of any combination of basic units, resulting in higher or lower dimensional units (m², 1/m or kg.m/s²).

Derived units compund of basic units (length, time, mass, temperature, electric current) are supported, Newton, Joule, Volt and Ohm units are also included as special derived units.

This library uses Dimensional arithmetic. In the dimensional analysis there are fundamental base quantities and the derived quantities. Dimension of basic quantities are like Length (L), Time (T), Mass (M), Electric Currency (A). Some dimensions of quantities like area are power of these dimensions (L²). Dimension of derived quantites such as Acceleration is (T⁻²L) and Force (T⁻²LM).

Quantities with same dimension are called Commensurable Quantities. Only Commensurable Quantities can be summed or sobtracted. On the otherhand, multiplication and division operations generates a quantity with a higher or lower dimension.

The demand for such libraries has grown alongside the development of engineering programs that require specific numbers with specified units. My solution eliminates the challenge of managing units by allowing you to focus on the metric types, such as MetricLength or MetricTime. The library takes care of the underlying mathematics, seamlessly handling unit conversions and enabling operations like unit to unit multiplication, resulting in higher or lower order units like m² or 1/m. Consider the Square class below:

Square sq = new Square(2.5.km(), 4.3.km(), 10.005.m());
Console.WriteLine(sq.Volume());

class Square
{
    MetricLength _length;
    MetricLength _width;
    MetricLength -height;

    public Square(MetricLength l, MetricLength w, MetricLength h)
    {
        _length = l; _width = w; _height = h;
    }
    public Metric Volume()
    {
        return _length * _width * _height;
    }
}

The units of the inputs of the constructor won't be a problem anymore. The same class can handle the values with various units (mm, m, cm) and return the same result with correct unit.

Extensiblity

Now custom units can be defined by the users of this library. Example of a Customunit:

// Special unit has to be registered
// call this method only once in the application
// derived degree indicates the exponents of length, time, mass and ampere unit components of the custom derived unit.
public static void TestCustomSpecialUnit()
    {
        // Registerethe CustomUnit only once
        CustomUnit.RegisterSpecialUnit(new DerivedDegree(2, -2, 2, 0), CustomUnit.Instance);

        var custom2 = (400.mm(2) / 9.minute(2)) * 100.g(2);
        var customUnit = (CustomUnit)DerivedUnit.New(2.m(2), 3.second(-2), 3.kg(2));

        string s1 = customUnit.ToString();
        string s2 = custom2.ToString();

        Console.WriteLine(s1); // 18,000000 m².kg²/sec²
        Console.WriteLine(s2); // 1,234568 mm².g²/sec²

        // change unit precision configuration
        UnitConfig.UnitPrecision = 3;
        string s3 = custom2.ToString();
        Console.WriteLine(s3); // 1,235 mm².g²/sec²

        // convert time unit to hour.
        CustomUnit convertedUNit = (CustomUnit)customUnit.ConvertTo(SiTimeUnits.hour);

        string s4 = convertedUNit?.ToString() ?? "null";
        Console.WriteLine(s4); // 233280000,000 m².kg²/hour²

        // convert length to metre
        convertedUNit = (CustomUnit)convertedUNit.ConvertTo(SiMetricUnits.kilometre);
        string s5 = convertedUNit?.ToString() ?? "null";
        Console.WriteLine(s5); // 233,280 km².kg²/hour²
    }

class CustomUnit : CustomSpecialUnit<CustomUnit>
    {
        public new string Symbol { get; } = "custom";
        /// <summary>
        /// This constructor is only for wrapping base class constructor.
        /// Values of each unit and the scaler value are multiplied and the result becomes the value of the initialized Customunit.
        /// </summary>
        CustomUnit(MetricLength l_unit, MetricTime t_unit, MetricMass m_unit, double scaler) : base(l_unit, t_unit, m_unit, scaler)
        {

        }
        /// <summary>
        /// This method is defined inside the base abstract class that is used for unit conversions.
        /// </summary>
        protected override CustomUnit New(MetricLength l_unit, MetricTime t_unit, MetricMass m_unit, Ampere a_unit)
        {
            return new CustomUnit(l_unit, t_unit, m_unit, 1);
        }
        /// <summary>
        /// This method is used as a delegate for registry of the CustomUnit.
        /// </summary>
        public static CustomUnit Instance(MetricLength l_unit, MetricTime t_unit, MetricMass m_unit, Ampere a_unit)
        {
            return new CustomUnit(l_unit, t_unit, m_unit, 1);
        }
    }

Examples

// now supports derived unit arithmetics and special units Joule and newton.
var speed = 2.km() / 1.hour();
var acc = speed / 1.hour();
var f2 = acc * 80.kg();
var e1 = f2 * 500.mm();
Joule e2 = (Joule)(f1 * 10.m());
Assert.IsTrue(e1 is Joule); //true
Assert.IsTrue(f2 is Newton); //true
Assert.IsTrue(e2 is Joule); //true

var speed = 1.m() / 1.second()
// 1 m/s

3.kg() / (2.m() * 2.second(2));
// 0,75 kg/m.s²

5.m(2) * 2.second(3) / 3.kg(2);
//10,000000000000002 m².s³/kg²

var m1 = 2.m();
// 2 m

m1.cm()
// 200 cm

var s1 = 3.hour();
// 3 s

s1.minute()
// 180 m

s1.second()
// 10800 s

var m12 = (2.mm() * 10.cm() + 4.m(2)).dm();
// 400,02000000000004 dm2

var m13 = 2 * m12;
// 800,0400000000001 dm2

var m14 = (m12 / 2).m();
// 2,0001 m²

Note: zero degree metrics [Metric(0)] are equal to scalers.

Conversions

Supported Units

Project Repository

https://github.com/kzlsahin/SiUnitsArithmetic

Contributions are welcome.

Lisance

This package is released under the MIT licence.