# Function config Set configuration options for math.js, and get current options. Will emit a 'config' event, with arguments (curr, prev, changes). ## Syntax ```js math.config(config: Object): Object ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `options` | Object | Available options: {number} epsilon Minimum relative difference between two compared values, used by all comparison functions. {string} matrix A string 'Matrix' (default) or 'Array'. {string} number A string 'number' (default), 'BigNumber', or 'Fraction' {number} precision The number of significant digits for BigNumbers. Not applicable for Numbers. {string} parenthesis How to display parentheses in LaTeX and string output. {string} randomSeed Random seed for seeded pseudo random number generator. Set to null to randomly seed. ### Returns Type | Description ---- | ----------- Object | Returns the current configuration ## Examples ```js math.config().number; // outputs 'number' math.eval('0.4'); // outputs number 0.4 math.config({number: 'Fraction'}); math.eval('0.4'); // outputs Fraction 2/5 ```