mathjs/docs/configuration.md

Configuration

Math.js contains a number of configuration settings. Configuration can be set when creating a math.js instance, or later on using the function config. Available configuration settings are:

• matrix. The default type of matrix output for functions. Available values are: 'matrix' (default) or 'array'. Where possible, the type of matrix output from functions is determined from the function input: An array as input will return an Array, a Matrix as input will return a Matrix. In case of no matrix as input, the type of output is determined by the option matrix. In case of mixed matrix inputs, a matrix will be returned always.

• number. The default type of numbers. This setting is used by functions like eval which cannot determine the correct type of output from the functions input. For most functions though, the type of output is determined from the the input: a number as input will return a number as output, a bignumber as input returns a bignumber as output. Available values are: 'number' (default) or 'bignumber'. Big numbers have higher precision than the default numbers of JavaScript.

• decimals. The maximum number of decimal places behind the decimal point (not the number of significant digits). Only applies to big numbers, not to numbers. Default value is 20.

  Important: This setting is applied application wide to all BigNumbers. Behind the scenes, this setting is applied as the global DECIMAL_PLACES setting of the bignumber.js library used by math.js.

Examples

This section shows a number of configuration examples.

Default settings

// load the library
var mathjs = require('mathjs');

// create an instance of math.js with default configuration
var math1 = mathjs();

// range will output a matrix
math1.range(0, 4); // Matrix [0, 1, 2, 3]

Configuration for matrices

// load the library
var mathjs = require('mathjs');

// create an instance of math.js with configuration settings
var settings = {
  matrix: 'array'
};
var math2 = mathjs(settings);

// range will output an Array
math2.range(0, 4); // Array [0, 1, 2, 3]

// change configuration
math2.config({
  matrix: 'matrix'
});

// range will output a Matrix
math2.range(0, 4); // Matrix [0, 1, 2, 3]

Configuration for big numbers

// load the library
var mathjs = require('mathjs');

// use big numbers by default
var math3 = mathjs({
  number: 'bignumber',
  decimals: 32
});

// parser will parse numbers as BigNumber now:
math3.eval('1 / 3'); // BigNumber, 0.33333333333333333333333333333333