thingtalk-units

A small library to convert and normalize between measurement units. This library is used by the ThingTalk language to support measurements.

The library converts to and from base units of various supported types, and various additional units for each base unit.

Usage

const TTUnits = require('thingtalk-units');

API

function normalizeUnit(unit : String) : String

Convert a unit name to the base unit, which is a standard unit for the same property. This method throws if the unit is invalid. Example:

TTUnits.normalizeUnit('F') === 'C'
TTUnits.normalizeUnit('km') === 'm'

function transformToBaseUnit(value : Number, unit : String) : Number

Convert the value value, expressed in the unit unit, in the same amount in the corresponding base unit. Example:

TTUnits.transformToBaseUnit(1, 'km') === 1000

function transformFromBaseUnit(value : Number, unit : String) : Number

Convert the value value, expressed in the base unit, to the unit unit. This is the inverse operation to transformToBaseUnit(). Example:

TTUnits.transformToBaseUnit(1000, 'km') === 1

const BaseUnit : Array

The list of the supported base units.

Supported Units

Base Units

• ms: time (milliseconds)
• m: distance (meters)
• mps: speed (meters per second)
• kg: mass (kilograms)
• Pa: pressure (Pascal)
• C: temperature (Celsius)
• kcal: energy (kilocalories)
• byte: data size (Byte)
• W: power (Watt)
• lm: luminous flux (lumen)
• lx: illuminance (lux)

The choice of base units is mostly historical. Some units follow SI convention (mps, kg, Pa), some follow common usage (kcal, C).

Additional Units

| Unit | Base Unit | Physical quantity | | --------------------------------- | --------- | ----------------- | | s (seconds) | ms | time | | min (minutes) | ms | time | | h (hours) | ms | time | | day (days) | ms | time | | week (weeks) | ms | time | | mon (business month = 30 days) | ms | time | | year (business year = 365 days) | ms | time | | km (kilometers) | m | distance | | mm (millimeters) | m | distance | | cm (centimeters) | m | distance | | mi (miles) | m | distance | | in (inches) | m | distance | | kmph (kilometers per hour) | mps | speed | | mph (miles per hour) | mps | speed | | g (grams) | kg | mass | | lb (US pound) | kg | mass | | oz (US ounce) | kg | mass | | bar (bar) | Pa | pressure | | psi (pounds per square inch) | Pa | pressure | | mmHg (millimeters of mercury) | Pa | pressure | | inHg (inches of mercury) | Pa | pressure | | F (Fahrenheit) | C | temperature | | K (Kelvin) | C | temperature | | kJ (kilojoule) | kcal | energy | | KB (kilobyte) | byte | data size | | KiB (kibibyte) | byte | data size | | MB (megabyte) | byte | data size | | MiB (mebibyte) | byte | data size | | GB (gigabyte) | byte | data size | | GiB (gibibyte) | byte | data size | | TB (terabyte) | byte | data size | | TiB (tebibyte) | byte | data size | | kW (kilowatt) | W | power |