math-digamma

    1.0.2 • Public • Published

    digamma

    NPM version Build Status Coverage Status Dependencies

    Digamma function.

    The digamma function ψ is the logarithmic derivative of the gamma function, i.e.

    Digamma function.

    Installation

    $ npm install math-digamma

    Usage

    var digamma = require( 'math-digamma' );

    digamma( x )

    Evaluates the digamma function.

    var v = digamma( -2.5 );
    // returns ~1.103
     
    = digamma( 1 );
    // returns ~-0.577
     
    = digamma( 10 );
    // returns ~2.252

    If x is 0 or a negative integer, the function returns NaN.

    var v = digamma( 0 );
    // returns NaN
     
    = digamma( -1 );
    // returns NaN
     
    = digamma( -2 );
    // returns NaN

    If provided NaN, the function returns NaN.

    var v = digamma( NaN );
    // returns NaN

    Examples

    var digamma = require( 'math-digamma' );
     
    var x;
    var v;
    var i;
     
    for ( i = 0; i < 10; i++ ) {
        x = Math.random()*10 - 5;
        v = digamma( x );
        console.log( 'x: %d, f(x): %d', x, v );
    }

    To run the example code from the top-level application directory,

    $ node ./examples/index.js

    Tests

    Unit

    This repository uses tape for unit tests. To run the tests, execute the following command in the top-level application directory:

    $ make test

    All new feature development should have corresponding unit tests to validate correct functionality.

    Test Coverage

    This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:

    $ make test-cov

    Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

    $ make view-cov

    Browser Support

    This repository uses Testling for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:

    $ make test-browsers

    To view the tests in a local web browser,

    $ make view-browser-tests

    License

    MIT license.

    Copyright

    Copyright © 2016. The Compute.io Authors.

    Install

    npm i math-digamma

    DownloadsWeekly Downloads

    6

    Version

    1.0.2

    License

    MIT

    Last publish

    Collaborators

    • kgryte
    • planeshifter