@stdlib/stats-base-dists-chisquare-ctor
v0.2.2
Published
Chi-squared distribution constructor.
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ChiSquare
Chi-squared distribution constructor.
Installation
npm install @stdlib/stats-base-dists-chisquare-ctor
Usage
var ChiSquare = require( '@stdlib/stats-base-dists-chisquare-ctor' );
ChiSquare( [k] )
Returns an chi-squared distribution object.
var chisquare = new ChiSquare();
var mu = chisquare.mean;
// returns 1.0
By default, k = 1.0
. To create a distribution having a different degrees of freedom k
, provide a parameter value.
var chisquare = new ChiSquare( 4.0 );
var mu = chisquare.mean;
// returns 4.0
chisquare
A chi-squared distribution object has the following properties and methods...
Writable Properties
chisquare.k
Rate parameter of the distribution. k
must be a positive number.
var chisquare = new ChiSquare( 2.0 );
var k = chisquare.k;
// returns 2.0
chisquare.k = 3.0;
k = chisquare.k;
// returns 3.0
Computed Properties
ChiSquare.prototype.entropy
Returns the differential entropy.
var chisquare = new ChiSquare( 4.0 );
var entropy = chisquare.entropy;
// returns ~2.27
ChiSquare.prototype.kurtosis
Returns the excess kurtosis.
var chisquare = new ChiSquare( 4.0 );
var kurtosis = chisquare.kurtosis;
// returns 3.0
ChiSquare.prototype.mean
Returns the expected value.
var chisquare = new ChiSquare( 4.0 );
var mu = chisquare.mean;
// returns 4.0
ChiSquare.prototype.median
Returns the median.
var chisquare = new ChiSquare( 4.0 );
var median = chisquare.median;
// returns ~3.357
ChiSquare.prototype.mode
Returns the mode.
var chisquare = new ChiSquare( 4.0 );
var mode = chisquare.mode;
// returns 2.0
ChiSquare.prototype.skewness
Returns the skewness.
var chisquare = new ChiSquare( 4.0 );
var skewness = chisquare.skewness;
// returns ~1.414
ChiSquare.prototype.stdev
Returns the standard deviation.
var chisquare = new ChiSquare( 4.0 );
var s = chisquare.stdev;
// returns ~2.828
ChiSquare.prototype.variance
Returns the variance.
var chisquare = new ChiSquare( 4.0 );
var s2 = chisquare.variance;
// returns 8.0
Methods
ChiSquare.prototype.cdf( x )
Evaluates the cumulative distribution function (CDF).
var chisquare = new ChiSquare( 2.0 );
var y = chisquare.cdf( 0.5 );
// returns ~0.221
ChiSquare.prototype.mgf( t )
Evaluates the moment-generating function (MGF).
var chisquare = new ChiSquare( 2.0 );
var y = chisquare.mgf( 0.2 );
// returns ~1.667
ChiSquare.prototype.pdf( x )
Evaluates the probability density function (PDF).
var chisquare = new ChiSquare( 2.0 );
var y = chisquare.pdf( 0.8 );
// returns ~0.335
ChiSquare.prototype.quantile( p )
Evaluates the quantile function at probability p
.
var chisquare = new ChiSquare( 2.0 );
var y = chisquare.quantile( 0.5 );
// returns ~1.386
y = chisquare.quantile( 1.9 );
// returns NaN
Examples
var ChiSquare = require( '@stdlib/stats-base-dists-chisquare-ctor' );
var chisquare = new ChiSquare( 2.0 );
var mu = chisquare.mean;
// returns 2.0
var mode = chisquare.mode;
// returns 0.0
var s2 = chisquare.variance;
// returns 4.0
var y = chisquare.cdf( 0.8 );
// returns ~0.33
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.