Built-in Units

While users can define their own unit system (see Defining Quantities), Safe Units also comes with a large collection of built-in quantities and units based on the SI unit system.

All quantities provided are generic, of the form type Quantity<N = number> so all quantity types will default to using number as the numeric type but may be passed another numeric type.

Base Units

The built-in units include the standard set of SI base dimension and corresponding units:

• Length / meters
• Mass / kilograms
• Time / seconds
• ElectricCurrent / amperes
• Temperature / kelvin
• AmountOfSubstance / moles
• LuminousIntensity / candelas

In addition, several extra dimensions are defined:

• PlaneAngle / radians
• SolidAngle / steradians
• Memory / bits

While plane and solid angles are defined as dimensionless in the SI specification, they are defined here in case users want to be more rigorous with their angles. If not, then these can be safely ignored.

Generic Base Units

The base units are only provided for number measures, but users can create the base units for a given measure type through:

type SpecialNumber = /* ... */;
const numericOps: NumericOperations<SpecialNumber> = {/* ... */};
const SpecialMeasure = createMeasureType(numericOps);
const {
    meters,
    kilograms,
    seconds,
    amperes,
    kelvin,
    moles,
    candelas,
    radians,
    steradians,
    bits,
} = createBaseUnits(SpecialMeasure);

These versions of meters, kilograms, etc. will all operator on measures whose numeric types are SpecialNumber.

Provided Units

A large number of built in quantities (e.g. distance, velocity, force and magnetic flux density) are provided. See here for a full list.

Many units are provided from the metric, Imperial and U.S. customary unit systems. See here for all of the units.

Prefix functions are provided for both standard SI prefixes and for memory prefixes.

Trigonometric functions are provided in the Trig namespace for converting between plane angles and dimensionless values, the signatures are as follows:

namespace Trig {
    function cos(x: PlaneAngle): Dimensionless;
    function sin(x: PlaneAngle): Dimensionless;
    function tan(x: PlaneAngle): Dimensionless;
    function acos(x: Dimensionless): PlaneAngle;
    function asin(x: Dimensionless): PlaneAngle;
    function atan(x: Dimensionless): PlaneAngle;
    function atan2(y: Length, x: Length): PlaneAngle;
}