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Beta distribution constructor.
npm install @stdlib/stats-base-dists-beta-ctorAlternatively,
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var Beta = require( '@stdlib/stats-base-dists-beta-ctor' );Returns a beta distribution object.
var beta = new Beta();
var mu = beta.mean;
// returns 0.5By default, alpha = 1.0 and beta = 1.0. To create a distribution having a different alpha (first shape parameter) and beta (second shape parameter), provide the corresponding arguments.
var beta = new Beta( 2.0, 4.0 );
var mu = beta.mean;
// returns ~0.333A beta distribution object has the following properties and methods...
First shape parameter of the distribution. alpha must be a positive number.
var beta = new Beta();
var alpha = beta.alpha;
// returns 1.0
beta.alpha = 3.0;
alpha = beta.alpha;
// returns 3.0Second shape parameter of the distribution. beta must be a positive number.
var beta = new Beta( 2.0, 4.0 );
var b = beta.beta;
// returns 4.0
beta.beta = 3.0;
b = beta.beta;
// returns 3.0Returns the differential entropy.
var beta = new Beta( 4.0, 12.0 );
var entropy = beta.entropy;
// returns ~-0.869Returns the excess kurtosis.
var beta = new Beta( 4.0, 12.0 );
var kurtosis = beta.kurtosis;
// returns ~0.082Returns the expected value.
var beta = new Beta( 4.0, 12.0 );
var mu = beta.mean;
// returns 0.25Returns the median.
var beta = new Beta( 4.0, 12.0 );
var median = beta.median;
// returns ~0.239Returns the mode.
var beta = new Beta( 4.0, 12.0 );
var mode = beta.mode;
// returns ~0.214Returns the skewness.
var beta = new Beta( 4.0, 12.0 );
var skewness = beta.skewness;
// returns ~0.529Returns the standard deviation.
var beta = new Beta( 4.0, 12.0 );
var s = beta.stdev;
// returns ~0.105Returns the variance.
var beta = new Beta( 4.0, 12.0 );
var s2 = beta.variance;
// returns ~0.011Evaluates the cumulative distribution function (CDF).
var beta = new Beta( 2.0, 4.0 );
var y = beta.cdf( 0.5 );
// returns ~0.813Evaluates the natural logarithm of the cumulative distribution function (CDF).
var beta = new Beta( 2.0, 4.0 );
var y = beta.logcdf( 0.5 );
// returns ~-0.208Evaluates the natural logarithm of the probability density function (PDF).
var beta = new Beta( 2.0, 4.0 );
var y = beta.logpdf( 0.8 );
// returns ~-2.0557Evaluates the moment-generating function (MGF).
var beta = new Beta( 2.0, 4.0 );
var y = beta.mgf( 0.5 );
// returns ~1.186Evaluates the probability density function (PDF).
var beta = new Beta( 2.0, 4.0 );
var y = beta.pdf( 0.8 );
// returns ~0.128Evaluates the quantile function at probability p.
var beta = new Beta( 2.0, 4.0 );
var y = beta.quantile( 0.5 );
// returns ~0.314
y = beta.quantile( 1.9 );
// returns NaNvar Beta = require( '@stdlib/stats-base-dists-beta-ctor' );
var beta = new Beta( 2.0, 4.0 );
var mu = beta.mean;
// returns ~0.333
var median = beta.median;
// returns ~0.314
var s2 = beta.variance;
// returns ~0.032
var y = beta.cdf( 0.8 );
// returns ~0.993This 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.
See LICENSE.
Copyright © 2016-2025. The Stdlib Authors.
