@neutrium/quantity/dist/operations/temperature.js

The NeutriumJS unit conversion module.

import { Decimal } from '@neutrium/math';
import { compareArray } from '@neutrium/utilities';
import { Quantity } from '../Quantity.js';
// Numbers for conversion
const FIVE_NINTHS = new Decimal("5").div("9");
const NINE_FIFTHS = new Decimal("9").div("5");
export function isTemperature(a) {
    return isDegrees(a) && /<temp-[CFRK]>/.test(a.numerator[0]);
}
export function isDegrees(a) {
    // signature may not have been calculated yet
    return (a.signature === null || a.signature === 400) &&
        a.numerator.length === 1 &&
        compareArray(a.denominator, ["<1>"]) &&
        (/<temp-[CFRK]>/.test(a.numerator[0]) || /<(kelvin|celsius|rankine|fahrenheit)>/.test(a.numerator[0]));
}
export function addTempDegrees(temp, deg) {
    let tempDegrees = deg.to(getDegreeUnits(temp.units()));
    return new Quantity({
        scalar: temp.scalar.add(tempDegrees.scalar),
        numerator: temp.numerator,
        denominator: temp.denominator
    });
}
export function subtractTemperatures(a, b) {
    let aUnits = a.units(), bConverted = b.to(aUnits), dstDegrees = new Quantity(getDegreeUnits(aUnits));
    return new Quantity({
        scalar: a.scalar.sub(bConverted.scalar),
        numerator: dstDegrees.numerator,
        denominator: dstDegrees.denominator
    });
}
export function subtractTempDegrees(temp, deg) {
    let tempDegrees = deg.to(getDegreeUnits(temp.units()));
    return new Quantity({
        scalar: temp.scalar.sub(tempDegrees.scalar),
        numerator: temp.numerator,
        denominator: temp.denominator
    });
}
export function toDegrees(src, dst) {
    let srcDegK = toDegK(src), dstUnits = dst.units(), dstScalar;
    switch (dstUnits) {
        case "degK":
            dstScalar = srcDegK.scalar;
            break;
        case "degC":
            dstScalar = srcDegK.scalar;
            break;
        case "degF":
            dstScalar = srcDegK.scalar.mul(NINE_FIFTHS);
            break;
        case "degR":
            dstScalar = srcDegK.scalar.mul(NINE_FIFTHS);
            break;
        default:
            throw new Error("Unknown type for degree conversion to: " + dstUnits);
    }
    return new Quantity({
        scalar: dstScalar,
        numerator: dst.numerator,
        denominator: dst.denominator
    });
}
export function toDegK(qty) {
    let units = qty.units(), q;
    if (units.match(/(deg)[CFRK]/)) {
        q = qty.baseScalar;
    }
    else {
        switch (units) {
            case "tempK":
                q = qty.scalar;
                break;
            case "tempC":
                q = qty.scalar;
                break;
            case "tempF":
                q = qty.scalar.mul(FIVE_NINTHS);
                break;
            case "tempR":
                q = qty.scalar.mul(FIVE_NINTHS);
                break;
            default: throw new Error("Unknown type for temp conversion from: " + units);
        }
    }
    return new Quantity({
        scalar: q,
        numerator: ["<kelvin>"],
        denominator: ["<1>"]
    });
}
export function toTemp(src, dst) {
    let dstUnits = dst.units(), dstScalar;
    switch (dstUnits) {
        case "tempK":
            dstScalar = src.baseScalar;
            break;
        case "tempC":
            dstScalar = src.baseScalar.sub("273.15");
            break;
        case "tempF":
            dstScalar = src.baseScalar.mul(NINE_FIFTHS).sub("459.67");
            break;
        case "tempR":
            dstScalar = src.baseScalar.mul(NINE_FIFTHS);
            break;
        default:
            throw new Error("Unknown type for temp conversion to: " + dstUnits);
    }
    return new Quantity({
        scalar: dstScalar,
        numerator: dst.numerator,
        denominator: dst.denominator
    });
}
export function toTempK(qty) {
    let units = qty.units(), q;
    if (units.match(/(deg)[CFRK]/)) {
        q = qty.baseScalar;
    }
    else {
        switch (units) {
            case "tempK":
                q = qty.scalar;
                break;
            case "tempC":
                q = qty.scalar.add("273.15");
                break;
            case "tempF":
                q = qty.scalar.add("459.67").mul(FIVE_NINTHS);
                break;
            case "tempR":
                q = qty.scalar.mul(FIVE_NINTHS);
                break;
            default:
                throw new Error("Unknown type for temp conversion from: " + units);
        }
    }
    return new Quantity({
        scalar: q,
        numerator: ["<temp-K>"],
        denominator: ["<1>"]
    });
}
// converts temp[C|K|F|R] to deg[C|K|F|R]
export function getDegreeUnits(units) {
    let degrees = 'CKFR', unit = units.slice(-1);
    if (degrees.indexOf(unit) !== -1) {
        return 'deg' + unit;
    }
    else {
        throw new Error("Unknown type for temp conversion from: " + units);
    }
}