@atomic-ehr/ucum/dist/special-functions.js

TypeScript implementation of UCUM (Unified Code for Units of Measure)

/**
 * Special function definitions for UCUM special units
 * Based on UCUM specification §21-§23
 */
// Registry of all 15 special functions used by 21 special units
const specialFunctions = new Map();
// Temperature Functions
specialFunctions.set('Cel', {
    name: 'Celsius',
    forward: (k) => k - 273.15,
    inverse: (c) => c + 273.15,
    inputDomain: (k) => k >= 0,
    outputDomain: (c) => c >= -273.15
});
specialFunctions.set('degF', {
    name: 'Fahrenheit',
    // Parameters value=5, unit=K/9 are incorporated
    forward: (k) => k * 9 / 5 - 459.67,
    inverse: (f) => (f + 459.67) * 5 / 9,
    inputDomain: (k) => k >= 0,
    outputDomain: (f) => f >= -459.67
});
specialFunctions.set('degRe', {
    name: 'Réaumur',
    // Parameters value=5, unit=K/4 are incorporated
    forward: (k) => (k - 273.15) * 4 / 5,
    inverse: (re) => re * 5 / 4 + 273.15,
    inputDomain: (k) => k >= 0,
    outputDomain: (re) => re >= -218.52
});
// Logarithmic Functions
specialFunctions.set('ln', {
    name: 'Natural logarithm',
    forward: (x) => Math.log(x),
    inverse: (x) => Math.exp(x),
    inputDomain: (x) => x > 0
});
specialFunctions.set('lg', {
    name: 'Common logarithm',
    forward: (x) => Math.log10(x),
    inverse: (x) => Math.pow(10, x),
    inputDomain: (x) => x > 0
});
specialFunctions.set('lgTimes2', {
    name: '2 × common logarithm',
    forward: (x) => 2 * Math.log10(x),
    inverse: (x) => Math.pow(10, x / 2),
    inputDomain: (x) => x > 0
});
specialFunctions.set('ld', {
    name: 'Binary logarithm',
    forward: (x) => Math.log2(x),
    inverse: (x) => Math.pow(2, x),
    inputDomain: (x) => x > 0
});
specialFunctions.set('pH', {
    name: 'pH scale',
    forward: (x) => -Math.log10(x),
    inverse: (x) => Math.pow(10, -x),
    inputDomain: (x) => x > 0
});
// Trigonometric Functions
specialFunctions.set('tanTimes100', {
    name: '100 × tangent (radians)',
    forward: (rad) => 100 * Math.tan(rad),
    inverse: (x) => Math.atan(x / 100)
});
specialFunctions.set('100tan', {
    name: '100 × tangent (degrees)',
    forward: (deg) => 100 * Math.tan(deg * Math.PI / 180),
    inverse: (x) => Math.atan(x / 100) * 180 / Math.PI
});
// Homeopathic Functions (retired but still supported)
specialFunctions.set('hpX', {
    name: 'Homeopathic decimal potency',
    forward: (x) => -Math.log10(x),
    inverse: (x) => Math.pow(10, -x),
    inputDomain: (x) => x > 0
});
specialFunctions.set('hpC', {
    name: 'Homeopathic centesimal potency',
    forward: (x) => -Math.log(x) / Math.log(100),
    inverse: (x) => Math.pow(100, -x),
    inputDomain: (x) => x > 0
});
specialFunctions.set('hpM', {
    name: 'Homeopathic millesimal potency',
    forward: (x) => -Math.log(x) / Math.log(1000),
    inverse: (x) => Math.pow(1000, -x),
    inputDomain: (x) => x > 0
});
specialFunctions.set('hpQ', {
    name: 'Homeopathic quintamillesimal potency',
    forward: (x) => -Math.log(x) / Math.log(50000),
    inverse: (x) => Math.pow(50000, -x),
    inputDomain: (x) => x > 0
});
// Mathematical Functions
specialFunctions.set('sqrt', {
    name: 'Square root',
    forward: (x) => Math.sqrt(x),
    inverse: (x) => x * x,
    inputDomain: (x) => x >= 0,
    outputDomain: (x) => x >= 0
});
/**
 * Get a special function definition by name
 */
export function getSpecialFunction(name) {
    return specialFunctions.get(name);
}
/**
 * Check if a function name corresponds to a special function
 */
export function isSpecialFunction(name) {
    return specialFunctions.has(name);
}
/**
 * Get all special function names
 */
export function getAllSpecialFunctionNames() {
    return Array.from(specialFunctions.keys());
}