number-scale

Convert numbers according to a given scale.

Avant propos

This module is heavily inspired from human-format. While there are still a strong base from that module, the API and behaviour is substantially different in number-scale.

Installation

npm install number-scale --save

Usage

var numberScale = require('number-scale');
 
var n = 123456.789;
 
console.log(numberScale(n));
// "123.46K"
 
console.log(numberScale(n, { 
  scale: 'time',
  roundMode: 'even',
  recursive: 3
}));
// [ '1d', '10h', '17m', '36.79s' ]

API

numberScale(n:Number[, options:Object]) : String|Array

A function receiving a number, and optionally some options, and return the scale (aka human readable) representation as a string.

• n:Number - any numeric value. If the argument is not a valid number, NaN is returned.
• options:Object - the formatting options
  • precision:Number - a numeric value indicating the number of decimal digits to round to. (Defaults to 2)
  • roundMode:String - the rounding method to use. May be one of the following : "up" always round up, "down" always round down, "even" round to nearest even value, "odd" round to nearest odd value. (Defaults to "up")
  • scale:String - the scale to use (see predefined scales, or custom scales.) (Defaults to "SI")
  • unit:String - the scale unit suffix (Defaults to "")
  • recursive:Number - instead of returning a string, return an array of length recursive + 1 elements.

NOTE : default options can be overridden by modifying numberScale.options.default.

Predefined Options

For convenience, these predefined options are specified

• numberScale.options.default:Object - predefined default options

numberScale.scales : Object

This is where the known scales are defined.

Known Scales

• SI - the International System of Units
• time - the time scale (i.e. day, hour, minute, second, milliseconds, microseconds, nanoseconds)
• IEEE1541 - is a powers of 2 scale for bytes measurements similar to the SI scale.

numberScale.defineScale(name:String, scale:Object, baseUnitValue:Number)

It is possible to define a new scale, or even override a current one, by calling numberScale.defineScale(name, scale, base) where scale is an Object defining the scale's properties. Take a look at the known scale definitions for more information.

Custom Scales

Custom scales are accessible just like any other scales, through the numberScale.scales object.

numberScale.parse(value:String|Array[, options:Object]) : Number

This is the inverse of numberScale(value, options). The function returns NaN is the given value cannot be parsed.

Contribution

All contributions welcome! Every PR must be accompanied by their associated unit tests!

License

The MIT License (MIT)

Copyright (c) 2014 Mind2Soft yanick.rochon@mind2soft.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.