@stdlib/stats-base-dists-chisquare-kurtosis NPM

Kurtosis

Chi-squared distribution excess kurtosis.

The excess kurtosis for a chi-squared random variable is

where k > 0 is the degrees of freedom.

Installation

npm install @stdlib/stats-base-dists-chisquare-kurtosis

Usage

var kurtosis = require( '@stdlib/stats-base-dists-chisquare-kurtosis' );

kurtosis( k )

Returns the excess kurtosis of a chi-squared distribution with degrees of freedom k.

var v = kurtosis( 9.0 );
// returns ~1.333

v = kurtosis( 0.5 );
// returns 24.0

If provided k <= 0, the function returns NaN.

var v = kurtosis( -1.0 );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var kurtosis = require( '@stdlib/stats-base-dists-chisquare-kurtosis' );

var k;
var v;
var i;

for ( i = 0; i < 10; i++ ) {
    k = randu() * 20.0;
    v = kurtosis( k );
    console.log( 'k: %d, Kurt(X,k): %d', k.toFixed( 4 ), v.toFixed( 4 ) );
}

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.