linear-big.js

A small, fast JavaScript library for arbitrary-precision decimal arithmetic.

The little little sister to big.js and bignumber.js. See also decimal.js, and here for the difference between them.

Load

The library is the single JavaScript file linear-big.js (or linear-big.min.js, which is linear-big.js minified).

It can be loaded via a script tag in an HTML document for the browser

<script src='./relative/path/to/big.js'></script>

or as a CommonJS, Node.js or AMD module using require.

var Big = require('linear-big.js');

For Node.js, the library is available from the npm registry:

$ npm install linear-big.js

Use

In all examples below, var, semicolons and toString calls are not shown. If a commented-out value is in quotes it means toString has been called on the preceding expression.

The library exports a single function: Big, the constructor of Big number instances. It accepts a value of type Number, String or Big number Object.

x = new Big(123.4567)
y = Big('123456.7e-3')             // 'new' is optional

A Big number is immutable in the sense that it is not changed by its methods.

0.3 - 0.1                          // 0.19999999999999998
x = new Big(0.3)
x.minus(0.1)                       // "0.2"
x                                  // "0.3"

The methods that return a Big number can be chained.

x.div(y).plus(z).times(9).minus('1.234567801234567e+8').plus(976.54321).div('2598.11772')

The maximum number of decimal places and the rounding mode used to round the results of the div method is determined by the value of the DP and RM properties of the Big number constructor.

(From v3.0.0, multiple Big number constructors can be created, see Change Log below.)

Big.DP = 10
Big.RM = 1

x = new Big(2);
y = new Big(3);
z = x.div(y)                       // "0.6666666667"
z.times(z)                         // "0.44444444448888888889"

The value of a Big number is stored in a decimal floating point format in terms of a coefficient, exponent and sign.

x = new Big(-123.456);
x.c                                // [1,2,3,4,5,6]    coefficient (i.e. significand)
x.e                                // 2                exponent
x.s                                // -1               sign

For further information see the API reference from the doc folder.

Test

The test directory contains the test scripts for each Big number method.

The tests can be run with Node or a browser.

To test all the methods from a command-line shell at the test directory,

$ node every-test

For the browser, see single-test.html and every-test.html in the test/browser directory.

Build

I.e. minify.

For Node, if uglify-js is installed globally ( npm install uglify-js -g ) then

uglifyjs -o ./linear-big.min.js ./linear-big.js

will create linear-big.min.js.

Feedback

Feedback is welcome.

Bugs/comments/questions? Open an issue, or email

Michael [email protected]

Bitcoin donation to: 1DppGRQSjVSMgGxuygDEHQuWEdTiVEzJYG Thank you

Licence

See LICENCE.