mathjs/lib/type/Unit.js
2013-08-14 15:39:21 +04:00

726 lines
29 KiB
JavaScript

var util = require('../util/index.js'),
number = util.number,
string = util.string,
isNumber = util.number.isNumber,
isString = util.string.isString;
/**
* @constructor Unit
*
* A unit can be constructed in the following ways:
* var a = new Unit(value, unit);
* var b = new Unit(null, unit);
* var c = Unit.parse(str);
*
* Example usage:
* var a = new Unit(5, 'cm'); // 50 mm
* var b = Unit.parse('23 kg'); // 23 kg
* var c = math.in(a, new Unit(null, 'm'); // 0.05 m
*
* @param {Number} [value] A value like 5.2
* @param {String} [unit] A unit like "cm" or "inch"
*/
function Unit(value, unit) {
if (!(this instanceof Unit)) {
throw new Error('Unit constructor must be called with the new operator');
}
if (value != null && !isNumber(value)) {
throw new TypeError('First parameter in Unit constructor must be a number');
}
if (unit != null && !isString(unit)) {
throw new TypeError('Second parameter in Unit constructor must be a string');
}
if (unit != null) {
// find the unit and prefix from the string
var res = _findUnit(unit);
if (!res) {
throw new SyntaxError('String "' + unit + '" is no unit');
}
this.unit = res.unit;
this.prefix = res.prefix;
}
else {
this.unit = UNIT_NONE;
this.prefix = PREFIX_NONE; // link to a list with supported prefixes
}
if (value != null) {
this.value = this._normalize(value);
this.fixPrefix = false; // is set true by the methods Unit.in and math.in
}
else {
this.value = null;
this.fixPrefix = true;
}
}
// private variables and functions for the Unit parser
var text, index, c;
function skipWhitespace() {
while (c == ' ' || c == '\t') {
next();
}
}
function isDigitDot (c) {
return ((c >= '0' && c <= '9') || c == '.');
}
function isDigit (c) {
return ((c >= '0' && c <= '9'));
}
function next() {
index++;
c = text.charAt(index);
}
function revert(oldIndex) {
index = oldIndex;
c = text.charAt(index);
}
function parseNumber () {
var number = '';
var oldIndex;
oldIndex = index;
if (c == '+') {
next();
}
else if (c == '-') {
number += c;
next();
}
if (!isDigitDot(c)) {
// a + or - must be followed by a digit
revert(oldIndex);
return null;
}
// get number, can have a single dot
if (c == '.') {
number += c;
next();
if (!isDigit(c)) {
// this is no legal number, it is just a dot
revert(oldIndex);
return null;
}
}
else {
while (isDigit(c)) {
number += c;
next();
}
if (c == '.') {
number += c;
next();
}
}
while (isDigit(c)) {
number += c;
next();
}
// check for scientific notation like "2.3e-4" or "1.23e50"
if (c == 'E' || c == 'e') {
number += c;
next();
if (c == '+' || c == '-') {
number += c;
next();
}
// Scientific notation MUST be followed by an exponent
if (!isDigit(c)) {
// this is no legal number, exponent is missing.
revert(oldIndex);
return null;
}
while (isDigit(c)) {
number += c;
next();
}
}
return number;
}
function parseUnit() {
var unit = '';
skipWhitespace();
while (c && c != ' ' && c != '\t') {
unit += c;
next();
}
return unit || null;
}
/**
* Parse a string into a unit. Returns null if the provided string does not
* contain a valid unit.
* @param {String} str A string like "5.2 inch", "4e2 kg"
* @return {Unit | null} unit
*/
Unit.parse = function parse(str) {
text = str;
index = -1;
c = '';
if (!isString(text)) {
return null;
}
next();
skipWhitespace();
var value = parseNumber();
var unit;
if (value) {
unit = parseUnit();
next();
skipWhitespace();
if (c) {
// garbage at the end. not good.
return null;
}
if (value && unit) {
return new Unit(Number(value), unit);
}
}
else {
unit = parseUnit();
next();
skipWhitespace();
if (c) {
// garbage at the end. not good.
return null;
}
return new Unit(null, unit)
}
return null;
};
/**
* Test whether value is of type Unit
* @param {*} value
* @return {Boolean} isUnit
*/
Unit.isUnit = function isUnit(value) {
return (value instanceof Unit);
};
/**
* create a copy of this unit
* @return {Unit} clone
*/
Unit.prototype.clone = function () {
var clone = new Unit();
for (var p in this) {
if (this.hasOwnProperty(p)) {
clone[p] = this[p];
}
}
return clone;
};
/**
* Normalize a value, based on its currently set unit
* @param {Number} value
* @return {Number} normalized value
* @private
*/
Unit.prototype._normalize = function(value) {
return (value + this.unit.offset) *
this.unit.value * this.prefix.value;
};
/**
* Unnormalize a value, based on its currently set unit
* @param {Number} value
* @param {Number} [prefixValue] Optional prefix value to be used
* @return {Number} unnormalized value
* @private
*/
Unit.prototype._unnormalize = function (value, prefixValue) {
if (prefixValue == undefined) {
return value / this.unit.value / this.prefix.value -
this.unit.offset;
}
else {
return value / this.unit.value / prefixValue -
this.unit.offset;
}
};
/**
* Find a unit from a string
* @param {String} str A string like 'cm' or 'inch'
* @returns {Object | null} result When found, an object with fields unit and
* prefix is returned. Else, null is returned.
* @private
*/
function _findUnit(str) {
for (var i = 0, iMax = UNITS.length; i < iMax; i++) {
var UNIT = UNITS[i];
if (string.endsWith(str, UNIT.name) ) {
var prefixLen = (str.length - UNIT.name.length);
var prefixName = str.substring(0, prefixLen);
var prefix = UNIT.prefixes[prefixName];
if (prefix !== undefined) {
// store unit, prefix, and value
return {
unit: UNIT,
prefix: prefix
};
}
}
}
return null;
}
/**
* Test if the given expression is a unit.
* The unit can have a prefix but cannot have a value.
* @param {String} unit A plain unit without value. Can have prefix, like "cm"
* @return {Boolean} true if the given string is a unit
*/
Unit.isPlainUnit = function (unit) {
return (_findUnit(unit) != null);
};
/**
* check if this unit has given base unit
* @param {BASE_UNITS | undefined} base
*/
Unit.prototype.hasBase = function(base) {
if (this.unit.base === undefined) {
return (base === undefined);
}
return (this.unit.base === base);
};
/**
* Check if this unit has a base equal to another base
* @param {Unit} other
* @return {Boolean} true if equal base
*/
Unit.prototype.equalBase = function(other) {
return (this.unit.base === other.unit.base);
};
/**
* Check if this unit equals another unit
* @param {Unit} other
* @return {Boolean} true if both units are equal
*/
Unit.prototype.equals = function(other) {
return (this.equalBase(other) && this.value == other.value);
};
/**
* Create a clone of this unit with a representation
* @param {String | Unit} plainUnit A plain unit, without value. Can have prefix, like "cm"
* @returns {Unit} unit having fixed, specified unit
*/
Unit.prototype['in'] = function (plainUnit) {
var other;
if (isString(plainUnit)) {
other = new Unit(null, plainUnit);
if (!this.equalBase(other)) {
throw new Error('Units do not match');
}
other.value = this.value;
return other;
}
else if (plainUnit instanceof Unit) {
if (!this.equalBase(plainUnit)) {
throw new Error('Units do not match');
}
if (plainUnit.value != null) {
throw new Error('Cannot convert to a unit with a value');
}
if (plainUnit.unit == null) {
throw new Error('Unit expected on the right hand side of function in');
}
other = plainUnit.clone();
other.value = this.value;
other.fixPrefix = true;
return other;
}
else {
throw new Error('String or Unit expected as parameter');
}
};
/**
* Return the value of the unit when represented with given plain unit
* @param {String | Unit} plainUnit For example 'cm' or 'inch'
* @return {Number} value
*/
Unit.prototype.toNumber = function (plainUnit) {
var other = this['in'](plainUnit);
var prefix = this.fixPrefix ? other._bestPrefix() : other.prefix;
return other._unnormalize(other.value, prefix.value);
};
/**
* Get string representation
* @return {String}
*/
Unit.prototype.toString = function() {
var value, str;
if (!this.fixPrefix) {
var bestPrefix = this._bestPrefix();
value = this._unnormalize(this.value, bestPrefix.value);
str = (this.value != null) ? number.format(value) + ' ' : '';
str += bestPrefix.name + this.unit.name;
}
else {
value = this._unnormalize(this.value);
str = (this.value != null) ? number.format(value) + ' ' : '';
str += this.prefix.name + this.unit.name;
}
return str;
};
/**
* Calculate the best prefix using current value.
* @returns {Object} prefix
* @private
*/
Unit.prototype._bestPrefix = function () {
// find the best prefix value (resulting in the value of which
// the absolute value of the log10 is closest to zero,
// though with a little offset of 1.2 for nicer values: you get a
// sequence 1mm 100mm 500mm 0.6m 1m 10m 100m 500m 0.6km 1km ...
var absValue = Math.abs(this.value / this.unit.value);
var bestPrefix = PREFIX_NONE;
var bestDiff = Math.abs(
Math.log(absValue / bestPrefix.value) / Math.LN10 - 1.2);
var prefixes = this.unit.prefixes;
for (var p in prefixes) {
if (prefixes.hasOwnProperty(p)) {
var prefix = prefixes[p];
if (prefix.scientific) {
var diff = Math.abs(
Math.log(absValue / prefix.value) / Math.LN10 - 1.2);
if (diff < bestDiff) {
bestPrefix = prefix;
bestDiff = diff;
}
}
}
}
return bestPrefix;
};
var PREFIXES = {
'NONE': {
'': {'name': '', 'value': 1, 'scientific': true}
},
'SHORT': {
'': {'name': '', 'value': 1, 'scientific': true},
'da': {'name': 'da', 'value': 1e1, 'scientific': false},
'h': {'name': 'h', 'value': 1e2, 'scientific': false},
'k': {'name': 'k', 'value': 1e3, 'scientific': true},
'M': {'name': 'M', 'value': 1e6, 'scientific': true},
'G': {'name': 'G', 'value': 1e9, 'scientific': true},
'T': {'name': 'T', 'value': 1e12, 'scientific': true},
'P': {'name': 'P', 'value': 1e15, 'scientific': true},
'E': {'name': 'E', 'value': 1e18, 'scientific': true},
'Z': {'name': 'Z', 'value': 1e21, 'scientific': true},
'Y': {'name': 'Y', 'value': 1e24, 'scientific': true},
'd': {'name': 'd', 'value': 1e-1, 'scientific': false},
'c': {'name': 'c', 'value': 1e-2, 'scientific': false},
'm': {'name': 'm', 'value': 1e-3, 'scientific': true},
// 'µ': {'name': 'µ', 'value': 1e-6, 'scientific': true},
'u': {'name': 'u', 'value': 1e-6, 'scientific': true},
'n': {'name': 'n', 'value': 1e-9, 'scientific': true},
'p': {'name': 'p', 'value': 1e-12, 'scientific': true},
'f': {'name': 'f', 'value': 1e-15, 'scientific': true},
'a': {'name': 'a', 'value': 1e-18, 'scientific': true},
'z': {'name': 'z', 'value': 1e-21, 'scientific': true},
'y': {'name': 'y', 'value': 1e-24, 'scientific': true}
},
'LONG': {
'': {'name': '', 'value': 1, 'scientific': true},
'deca': {'name': 'deca', 'value': 1e1, 'scientific': false},
'hecto': {'name': 'hecto', 'value': 1e2, 'scientific': false},
'kilo': {'name': 'kilo', 'value': 1e3, 'scientific': true},
'mega': {'name': 'mega', 'value': 1e6, 'scientific': true},
'giga': {'name': 'giga', 'value': 1e9, 'scientific': true},
'tera': {'name': 'tera', 'value': 1e12, 'scientific': true},
'peta': {'name': 'peta', 'value': 1e15, 'scientific': true},
'exa': {'name': 'exa', 'value': 1e18, 'scientific': true},
'zetta': {'name': 'zetta', 'value': 1e21, 'scientific': true},
'yotta': {'name': 'yotta', 'value': 1e24, 'scientific': true},
'deci': {'name': 'deci', 'value': 1e-1, 'scientific': false},
'centi': {'name': 'centi', 'value': 1e-2, 'scientific': false},
'milli': {'name': 'milli', 'value': 1e-3, 'scientific': true},
'micro': {'name': 'micro', 'value': 1e-6, 'scientific': true},
'nano': {'name': 'nano', 'value': 1e-9, 'scientific': true},
'pico': {'name': 'pico', 'value': 1e-12, 'scientific': true},
'femto': {'name': 'femto', 'value': 1e-15, 'scientific': true},
'atto': {'name': 'atto', 'value': 1e-18, 'scientific': true},
'zepto': {'name': 'zepto', 'value': 1e-21, 'scientific': true},
'yocto': {'name': 'yocto', 'value': 1e-24, 'scientific': true}
},
'BINARY_SHORT': {
'': {'name': '', 'value': 1, 'scientific': true},
'k': {'name': 'k', 'value': 1024, 'scientific': true},
'M': {'name': 'M', 'value': Math.pow(1024, 2), 'scientific': true},
'G': {'name': 'G', 'value': Math.pow(1024, 3), 'scientific': true},
'T': {'name': 'T', 'value': Math.pow(1024, 4), 'scientific': true},
'P': {'name': 'P', 'value': Math.pow(1024, 5), 'scientific': true},
'E': {'name': 'E', 'value': Math.pow(1024, 6), 'scientific': true},
'Z': {'name': 'Z', 'value': Math.pow(1024, 7), 'scientific': true},
'Y': {'name': 'Y', 'value': Math.pow(1024, 8), 'scientific': true},
'Ki': {'name': 'Ki', 'value': 1024, 'scientific': true},
'Mi': {'name': 'Mi', 'value': Math.pow(1024, 2), 'scientific': true},
'Gi': {'name': 'Gi', 'value': Math.pow(1024, 3), 'scientific': true},
'Ti': {'name': 'Ti', 'value': Math.pow(1024, 4), 'scientific': true},
'Pi': {'name': 'Pi', 'value': Math.pow(1024, 5), 'scientific': true},
'Ei': {'name': 'Ei', 'value': Math.pow(1024, 6), 'scientific': true},
'Zi': {'name': 'Zi', 'value': Math.pow(1024, 7), 'scientific': true},
'Yi': {'name': 'Yi', 'value': Math.pow(1024, 8), 'scientific': true}
},
'BINARY_LONG': {
'': {'name': '', 'value': 1, 'scientific': true},
'kilo': {'name': 'kilo', 'value': 1024, 'scientific': true},
'mega': {'name': 'mega', 'value': Math.pow(1024, 2), 'scientific': true},
'giga': {'name': 'giga', 'value': Math.pow(1024, 3), 'scientific': true},
'tera': {'name': 'tera', 'value': Math.pow(1024, 4), 'scientific': true},
'peta': {'name': 'peta', 'value': Math.pow(1024, 5), 'scientific': true},
'exa': {'name': 'exa', 'value': Math.pow(1024, 6), 'scientific': true},
'zetta': {'name': 'zetta', 'value': Math.pow(1024, 7), 'scientific': true},
'yotta': {'name': 'yotta', 'value': Math.pow(1024, 8), 'scientific': true},
'kibi': {'name': 'kibi', 'value': 1024, 'scientific': true},
'mebi': {'name': 'mebi', 'value': Math.pow(1024, 2), 'scientific': true},
'gibi': {'name': 'gibi', 'value': Math.pow(1024, 3), 'scientific': true},
'tebi': {'name': 'tebi', 'value': Math.pow(1024, 4), 'scientific': true},
'pebi': {'name': 'pebi', 'value': Math.pow(1024, 5), 'scientific': true},
'exi': {'name': 'exi', 'value': Math.pow(1024, 6), 'scientific': true},
'zebi': {'name': 'zebi', 'value': Math.pow(1024, 7), 'scientific': true},
'yobi': {'name': 'yobi', 'value': Math.pow(1024, 8), 'scientific': true}
}
};
var PREFIX_NONE = {'name': '', 'value': 1, 'scientific': true};
var BASE_UNITS = {
'NONE': {},
'LENGTH': {}, // meter
'MASS': {}, // kilogram
'TIME': {}, // second
'CURRENT': {}, // ampere
'TEMPERATURE': {}, // kelvin
'LUMINOUS_INTENSITY': {}, // candela
'AMOUNT_OF_SUBSTANCE': {}, // mole
'FORCE': {}, // Newton
'SURFACE': {}, // m2
'VOLUME': {}, // m3
'ANGLE': {}, // rad
'BIT': {} // bit (digital)
};
BASE_UNIT_NONE = {};
UNIT_NONE = {'name': '', 'base': BASE_UNIT_NONE, 'value': 1, 'offset': 0};
var UNITS = [
// length
{'name': 'meter', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.LONG, 'value': 1, 'offset': 0},
{'name': 'inch', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.0254, 'offset': 0},
{'name': 'foot', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.3048, 'offset': 0},
{'name': 'yard', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.9144, 'offset': 0},
{'name': 'mile', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 1609.344, 'offset': 0},
{'name': 'link', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.201168, 'offset': 0},
{'name': 'rod', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 5.029210, 'offset': 0},
{'name': 'chain', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 20.1168, 'offset': 0},
{'name': 'angstrom', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 1e-10, 'offset': 0},
{'name': 'm', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.SHORT, 'value': 1, 'offset': 0},
//{'name': 'in', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.0254, 'offset': 0}, not supported, In is an operator
{'name': 'ft', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.3048, 'offset': 0},
{'name': 'yd', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.9144, 'offset': 0},
{'name': 'mi', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 1609.344, 'offset': 0},
{'name': 'li', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.201168, 'offset': 0},
{'name': 'rd', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 5.029210, 'offset': 0},
{'name': 'ch', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 20.1168, 'offset': 0},
{'name': 'mil', 'base': BASE_UNITS.LENGTH, 'prefixes': PREFIXES.NONE, 'value': 0.0000254, 'offset': 0}, // 1/1000 inch
// Surface
{'name': 'm2', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.SHORT, 'value': 1, 'offset': 0},
{'name': 'sqin', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 0.00064516, 'offset': 0}, // 645.16 mm2
{'name': 'sqft', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 0.09290304, 'offset': 0}, // 0.09290304 m2
{'name': 'sqyd', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 0.83612736, 'offset': 0}, // 0.83612736 m2
{'name': 'sqmi', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 2589988.110336, 'offset': 0}, // 2.589988110336 km2
{'name': 'sqrd', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 25.29295, 'offset': 0}, // 25.29295 m2
{'name': 'sqch', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 404.6873, 'offset': 0}, // 404.6873 m2
{'name': 'sqmil', 'base': BASE_UNITS.SURFACE, 'prefixes': PREFIXES.NONE, 'value': 6.4516e-10, 'offset': 0}, // 6.4516 * 10^-10 m2
// Volume
{'name': 'm3', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.SHORT, 'value': 1, 'offset': 0},
{'name': 'L', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.SHORT, 'value': 0.001, 'offset': 0}, // litre
{'name': 'litre', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.LONG, 'value': 0.001, 'offset': 0},
{'name': 'cuin', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 1.6387064e-5, 'offset': 0}, // 1.6387064e-5 m3
{'name': 'cuft', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.028316846592, 'offset': 0}, // 28.316 846 592 L
{'name': 'cuyd', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.764554857984, 'offset': 0}, // 764.554 857 984 L
{'name': 'teaspoon', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.000005, 'offset': 0}, // 5 mL
{'name': 'tablespoon', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.000015, 'offset': 0}, // 15 mL
//{'name': 'cup', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.000240, 'offset': 0}, // 240 mL // not possible, we have already another cup
// Liquid volume
{'name': 'minim', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.00000006161152, 'offset': 0}, // 0.06161152 mL
{'name': 'fluiddram', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0000036966911, 'offset': 0}, // 3.696691 mL
{'name': 'fluidounce', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.00002957353, 'offset': 0}, // 29.57353 mL
{'name': 'gill', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0001182941, 'offset': 0}, // 118.2941 mL
{'name': 'cup', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0002365882, 'offset': 0}, // 236.5882 mL
{'name': 'pint', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0004731765, 'offset': 0}, // 473.1765 mL
{'name': 'quart', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0009463529, 'offset': 0}, // 946.3529 mL
{'name': 'gallon', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.003785412, 'offset': 0}, // 3.785412 L
{'name': 'beerbarrel', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.1173478, 'offset': 0}, // 117.3478 L
{'name': 'oilbarrel', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.1589873, 'offset': 0}, // 158.9873 L
{'name': 'hogshead', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.2384810, 'offset': 0}, // 238.4810 L
//{'name': 'min', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.00000006161152, 'offset': 0}, // 0.06161152 mL // min is already in use as minute
{'name': 'fldr', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0000036966911, 'offset': 0}, // 3.696691 mL
{'name': 'floz', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.00002957353, 'offset': 0}, // 29.57353 mL
{'name': 'gi', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0001182941, 'offset': 0}, // 118.2941 mL
{'name': 'cp', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0002365882, 'offset': 0}, // 236.5882 mL
{'name': 'pt', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0004731765, 'offset': 0}, // 473.1765 mL
{'name': 'qt', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.0009463529, 'offset': 0}, // 946.3529 mL
{'name': 'gal', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.003785412, 'offset': 0}, // 3.785412 L
{'name': 'bbl', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.1173478, 'offset': 0}, // 117.3478 L
{'name': 'obl', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.1589873, 'offset': 0}, // 158.9873 L
//{'name': 'hogshead', 'base': BASE_UNITS.VOLUME, 'prefixes': PREFIXES.NONE, 'value': 0.2384810, 'offset': 0}, // 238.4810 L // TODO: hh?
// Mass
{'name': 'g', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.SHORT, 'value': 0.001, 'offset': 0},
{'name': 'gram', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.LONG, 'value': 0.001, 'offset': 0},
{'name': 'ton', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.SHORT, 'value': 907.18474, 'offset': 0},
{'name': 'tonne', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.SHORT, 'value': 1000, 'offset': 0},
{'name': 'grain', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 64.79891e-6, 'offset': 0},
{'name': 'dram', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 1.7718451953125e-3, 'offset': 0},
{'name': 'ounce', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 28.349523125e-3, 'offset': 0},
{'name': 'poundmass', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 453.59237e-3, 'offset': 0},
{'name': 'hundredweight', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 45.359237, 'offset': 0},
{'name': 'stick', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 115e-3, 'offset': 0},
{'name': 'gr', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 64.79891e-6, 'offset': 0},
{'name': 'dr', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 1.7718451953125e-3, 'offset': 0},
{'name': 'oz', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 28.349523125e-3, 'offset': 0},
{'name': 'lbm', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 453.59237e-3, 'offset': 0},
{'name': 'cwt', 'base': BASE_UNITS.MASS, 'prefixes': PREFIXES.NONE, 'value': 45.359237, 'offset': 0},
// Time
{'name': 's', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.SHORT, 'value': 1, 'offset': 0},
{'name': 'min', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 60, 'offset': 0},
{'name': 'h', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 3600, 'offset': 0},
{'name': 'seconds', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.LONG, 'value': 1, 'offset': 0},
{'name': 'second', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.LONG, 'value': 1, 'offset': 0},
{'name': 'sec', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.LONG, 'value': 1, 'offset': 0},
{'name': 'minutes', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 60, 'offset': 0},
{'name': 'minute', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 60, 'offset': 0},
{'name': 'hours', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 3600, 'offset': 0},
{'name': 'hour', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 3600, 'offset': 0},
{'name': 'day', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 86400, 'offset': 0},
{'name': 'days', 'base': BASE_UNITS.TIME, 'prefixes': PREFIXES.NONE, 'value': 86400, 'offset': 0},
// Angles
{'name': 'rad', 'base': BASE_UNITS.ANGLE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
{'name': 'deg', 'base': BASE_UNITS.ANGLE, 'prefixes': PREFIXES.NONE, 'value': 0.017453292519943295769236907684888, 'offset': 0}, // deg = rad / (2*pi) * 360 = rad / 0.017453292519943295769236907684888
{'name': 'grad', 'base': BASE_UNITS.ANGLE, 'prefixes': PREFIXES.NONE, 'value': 0.015707963267948966192313216916399, 'offset': 0}, // grad = rad / (2*pi) * 400 = rad / 0.015707963267948966192313216916399
{'name': 'cycle', 'base': BASE_UNITS.ANGLE, 'prefixes': PREFIXES.NONE, 'value': 6.2831853071795864769252867665793, 'offset': 0}, // cycle = rad / (2*pi) = rad / 6.2831853071795864769252867665793
// Electric current
{'name': 'A', 'base': BASE_UNITS.CURRENT, 'prefixes': PREFIXES.SHORT, 'value': 1, 'offset': 0},
{'name': 'ampere', 'base': BASE_UNITS.CURRENT, 'prefixes': PREFIXES.LONG, 'value': 1, 'offset': 0},
// Temperature
// K(C) = °C + 273.15
// K(F) = (°F + 459.67) / 1.8
// K(R) = °R / 1.8
{'name': 'K', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
{'name': 'degC', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 273.15},
{'name': 'degF', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1/1.8, 'offset': 459.67},
{'name': 'degR', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1/1.8, 'offset': 0},
{'name': 'kelvin', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
{'name': 'celsius', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 273.15},
{'name': 'fahrenheit', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1/1.8, 'offset': 459.67},
{'name': 'rankine', 'base': BASE_UNITS.TEMPERATURE, 'prefixes': PREFIXES.NONE, 'value': 1/1.8, 'offset': 0},
// amount of substance
{'name': 'mol', 'base': BASE_UNITS.AMOUNT_OF_SUBSTANCE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
{'name': 'mole', 'base': BASE_UNITS.AMOUNT_OF_SUBSTANCE, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
// luminous intensity
{'name': 'cd', 'base': BASE_UNITS.LUMINOUS_INTENSITY, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
{'name': 'candela', 'base': BASE_UNITS.LUMINOUS_INTENSITY, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
// TODO: units STERADIAN
//{'name': 'sr', 'base': BASE_UNITS.STERADIAN, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
//{'name': 'steradian', 'base': BASE_UNITS.STERADIAN, 'prefixes': PREFIXES.NONE, 'value': 1, 'offset': 0},
// Force
{'name': 'N', 'base': BASE_UNITS.FORCE, 'prefixes': PREFIXES.SHORT, 'value': 1, 'offset': 0},
{'name': 'newton', 'base': BASE_UNITS.FORCE, 'prefixes': PREFIXES.LONG, 'value': 1, 'offset': 0},
{'name': 'lbf', 'base': BASE_UNITS.FORCE, 'prefixes': PREFIXES.NONE, 'value': 4.4482216152605, 'offset': 0},
{'name': 'poundforce', 'base': BASE_UNITS.FORCE, 'prefixes': PREFIXES.NONE, 'value': 4.4482216152605, 'offset': 0},
// Binary
{'name': 'b', 'base': BASE_UNITS.BIT, 'prefixes': PREFIXES.BINARY_SHORT, 'value': 1, 'offset': 0},
{'name': 'bits', 'base': BASE_UNITS.BIT, 'prefixes': PREFIXES.BINARY_LONG, 'value': 1, 'offset': 0},
{'name': 'B', 'base': BASE_UNITS.BIT, 'prefixes': PREFIXES.BINARY_SHORT, 'value': 8, 'offset': 0},
{'name': 'bytes', 'base': BASE_UNITS.BIT, 'prefixes': PREFIXES.BINARY_LONG, 'value': 8, 'offset': 0}
];
Unit.PREFIXES = PREFIXES;
Unit.BASE_UNITS = BASE_UNITS;
Unit.UNITS = UNITS;
// exports
module.exports = Unit;
// to trick my IDE which doesn't get it
exports.isUnit = Unit.isUnit;
exports.isPlainUnit = Unit.isPlainUnit;
exports.parse = Unit.parse;
util.types.addType('unit', Unit);