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Kumaraswamy
Kumaraswamy's double bounded distribution constructor.
Installation
npm install @stdlib/stats-base-dists-kumaraswamy-ctor
Usage
var Kumaraswamy = require( '@stdlib/stats-base-dists-kumaraswamy-ctor' );
Kumaraswamy( [a, b] )
Returns a Kumaraswamy's double bounded distribution object.
var kumaraswamy = new Kumaraswamy();
var mu = kumaraswamy.mean;
// returns 0.5
By default, a = 1.0
and b = 1.0
. To create a distribution having a different a
(first shape parameter) and b
(second shape parameter), provide the corresponding arguments.
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var mu = kumaraswamy.mean;
// returns ~0.406
kumaraswamy
A Kumaraswamy's double bounded distribution object has the following properties and methods...
Writable Properties
kumaraswamy.a
First shape parameter of the distribution. a
must be a positive number.
var kumaraswamy = new Kumaraswamy();
var a = kumaraswamy.a;
// returns 1.0
kumaraswamy.a = 3.0;
a = kumaraswamy.a;
// returns 3.0
kumaraswamy.b
Second shape parameter of the distribution. b
must be a positive number.
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var b = kumaraswamy.b;
// returns 4.0
kumaraswamy.b = 3.0;
b = kumaraswamy.b;
// returns 3.0
Computed Properties
Kumaraswamy.prototype.kurtosis
Returns the excess kurtosis.
var kumaraswamy = new Kumaraswamy( 4.0, 12.0 );
var kurtosis = kumaraswamy.kurtosis;
// returns ~2.704
Kumaraswamy.prototype.mean
Returns the expected value.
var kumaraswamy = new Kumaraswamy( 4.0, 12.0 );
var mu = kumaraswamy.mean;
// returns ~0.481
Kumaraswamy.prototype.mode
Returns the mode.
var kumaraswamy = new Kumaraswamy( 4.0, 12.0 );
var mode = kumaraswamy.mode;
// returns ~0.503
Kumaraswamy.prototype.skewness
Returns the skewness.
var kumaraswamy = new Kumaraswamy( 4.0, 12.0 );
var skewness = kumaraswamy.skewness;
// returns ~-0.201
Kumaraswamy.prototype.stdev
Returns the standard deviation.
var kumaraswamy = new Kumaraswamy( 4.0, 12.0 );
var s = kumaraswamy.stdev;
// returns ~0.13
Kumaraswamy.prototype.variance
Returns the variance.
var kumaraswamy = new Kumaraswamy( 4.0, 12.0 );
var s2 = kumaraswamy.variance;
// returns ~0.017
Methods
Kumaraswamy.prototype.cdf( x )
Evaluates the cumulative distribution function (CDF).
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var y = kumaraswamy.cdf( 0.5 );
// returns ~0.684
Kumaraswamy.prototype.logcdf( x )
Evaluates the natural logarithm of the cumulative distribution function (CDF).
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var y = kumaraswamy.logcdf( 0.5 );
// returns ~-0.38
Kumaraswamy.prototype.logpdf( x )
Evaluates the natural logarithm of the probability density function (PDF).
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var y = kumaraswamy.logpdf( 0.8 );
// returns ~-1.209
Kumaraswamy.prototype.pdf( x )
Evaluates the probability density function (PDF).
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var y = kumaraswamy.pdf( 0.8 );
// returns ~0.299
Kumaraswamy.prototype.quantile( p )
Evaluates the quantile function at probability p
.
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var y = kumaraswamy.quantile( 0.5 );
// returns ~0.399
y = kumaraswamy.quantile( 1.9 );
// returns NaN
Examples
var Kumaraswamy = require( '@stdlib/stats-base-dists-kumaraswamy-ctor' );
var kumaraswamy = new Kumaraswamy( 2.0, 4.0 );
var mu = kumaraswamy.mean;
// returns ~0.406
var mode = kumaraswamy.mode;
// returns ~0.378
var s2 = kumaraswamy.variance;
// returns ~0.035
var y = kumaraswamy.cdf( 0.8 );
// returns ~0.983
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.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.