Measurements

A Measurement object represents a quantity and unit of measure. The Measurement type provides a programmatic interface to converting measurements into different units, as well as calculating the sum or difference between two measurements.

Measurements are initialized with a UnitMeasure and a value.

Measurements support operator functions, including scale, add, subtract, divide as well as comparison and equality operators.

import { Measurement, UnitEnergy } from "measurements";

//Declare a value that holds 100 calories
const caloriesValue = new Measurement(100, UnitEnergy.calories);

//Convert it to kiloJoules
const kiloJoulesValue = caloriesValue.converted(UnitEnergy.kiloJoules);

//Print a formatted label
console.log(kiloJoulesValue.shortLabel);

//Add the two energy values together, the unit type is the last parameter used
const addedValues = UnitEnergy.add(caloriesValue,kiloJoulesValue);
console.log(addedValues.longLabel);

//Check if two values are equal
const equals = UnitEnergy.equal(caloriesValue,kiloJoulesValue);
console.log(equals);

API

All measurments share a common API.

• converted(unit: MeasurementType): Measurement<MeasurementType>

  Converts a mesaurement from a specific unit type to another

const calories = new Measurement(100, UnitEnergy.calories)
const kilojoules = calories.converted(UnitEnergy.kiloJoules)

or

const meters = new Measurement(100, UnitLength.meters)
const kilometers = meters.converted(UnitLength.kilometers)

Measurement objects are mutable

• convert(to: MeasurementType)

  Transforms a measurement from its existing type to another

const weight = new Measurement(1, UnitMass.kilograms)
weight.convert(UnitMass.grams)

Get values from a measurement

• measure.name

  Returns the name of the measurement e.g. Kilograms

• measure.symbol

  Returns the symbol of the measurment e.g. kg

• measure.shortLabel

  Returns a formatted label with the value and symbol e.g. 100 L

• measure.longLabel

  Returns a full label with value and name e.g. 100 Kilograms

Perform Operations on measurements

All operations return new Measurement object

• Measurement.add(gramsValue, kilosVaulue)

  Takes two measurmenets of same dimensions and performs addition operation

• Measurement.scale(2, gramsValue)

  Takes a scalar value e.g. 2 and applies it to measurement

• Measurement.substract(kilosValue, gramsValue)

  Takes two measurements of same dimensions and performs substraction

• Measurement.divide(kilosValue, gramsValue)

  Takes two measurments of same dimensions and performs division

Perform Equality check on measurements

• Measurement.equals(m1, m2): boolean

  Takes two measurements of same dimension and returns true if they're equal

• Measurement.netEquals(m1, m2): boolean

  Takes two measurements of same dimension and returns true if they're not equal

• Measurement.greaterThan(m1, m2): boolean

  Takes two measurements and checks if the first measure is greater than the second measure

• Measurement.lessThan(m1, m2): boolean

  Takes two measurements and checks if the first measure is less than the second measure

• Measurement.greaterThanOrEqual(m1, m2): boolean

  Takes two measurements and checks if the first measure is greater than or equal the second measure

• Measurement.lessThanOrEqual(m1, m2): boolean

  Takes two measurements and checks if the first measure is less than or equal the second measure

Supported MeasurementTypes

• UnitEnergy

  This measurement type supports kilojoules, joules, kilocalories, calories & kilowattHours.

  The base unit is joules.

• UnitMass

  This measurement type supports kilograms, grams, decigrams, centigrams, milligrams, micrograms, nanograms, picograms, ounces, pounds, stones, metricTons, shortTons, carats, ouncesTroy, slugs.

  The base unit is kilograms.

• UnitLength

  This measurement type supports megameters, kilometers, hectometers, decameters, meters, decimeters, centimeters, millimeters, micrometers, nanometers, picometers, inches, feet, yards, miles, scandinavianMiles, lightyears, fathoms, furlongs, astronomicalUnits, parsecs.

  The base unit is meters/

• UnitVolume

  This measurement type supports megaliters, kiloliters, liters, deciliters, centiliters, milliliters, cubicKilometers, cubicMeters, cubicDecimeters, cubicMilliliters, cubicInches, cubicFeet, cubicYards, cubicMiles, acreFeet, bushels, teaspoons, tablespoons, fluidOunces, cups, pints, quarts, gallons, imperialTeaspoons, imperialTablespoons, imperialFluidOunces, imperialPints, imperialQuarts, imperialGallons, metricCups.

  The base unit is liters.

• UnitTemperature

  This measurement type supports kelvin, celsius, fahrenheit.

  The base unit is kelvin.

Examples

Convert celsius to fahrenheit

const celsius = new Measurement(32, UnitTemperature.celsius);
const fahrenheit = celsius.converted(UnitTemperature.fahrenheit);
console.log(fahrenheit.shortLabel)

More Measurement Dimensions To Come

The following is a list to be implemented

UnitAcceleration UnitAngle UnitArea UnitConcentrationMass UnitDisperion UnitDuration UnitElectricalCharge UnitElectricCurrent UnitElectricPotentialDifference UnitElectricResistance UnitFrequency UnitFuelEfficiency UnitIllumination UnitInformationStorage UnitPower UnitPressure UnitSpeed

Custom measurement types and overrides coming soon