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Erlang distribution constructor.
npm install @stdlib/stats-base-dists-erlang-ctor
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var Erlang = require( '@stdlib/stats-base-dists-erlang-ctor' );
Returns an Erlang distribution object.
var erlang = new Erlang();
var mode = erlang.mode;
// returns 0.0
By default, k = 1.0
and lambda = 1.0
. To create a distribution having a different k
(shape parameter) and lambda
(rate parameter), provide the corresponding arguments.
var erlang = new Erlang( 2, 4.0 );
var mode = erlang.mode;
// returns 0.25
An Erlang distribution object has the following properties and methods...
Shape parameter of the distribution. k
must be a positive integer.
var erlang = new Erlang();
var k = erlang.k;
// returns 1.0
erlang.k = 3.0;
k = erlang.k;
// returns 3.0
Rate parameter of the distribution. lambda
must be a positive number.
var erlang = new Erlang( 2, 4.0 );
var lambda = erlang.lambda;
// returns 4.0
erlang.lambda = 3.0;
lambda = erlang.lambda;
// returns 3.0
Returns the differential entropy.
var erlang = new Erlang( 4, 12.0 );
var entropy = erlang.entropy;
// returns ~-0.462
Returns the excess kurtosis.
var erlang = new Erlang( 4, 12.0 );
var kurtosis = erlang.kurtosis;
// returns 1.5
Returns the expected value.
var erlang = new Erlang( 4, 12.0 );
var mu = erlang.mean;
// returns ~0.333
Returns the mode.
var erlang = new Erlang( 4, 12.0 );
var mode = erlang.mode;
// returns 0.25
Returns the skewness.
var erlang = new Erlang( 4, 12.0 );
var skewness = erlang.skewness;
// returns 1.0
Returns the standard deviation.
var erlang = new Erlang( 4, 12.0 );
var s = erlang.stdev;
// returns ~0.167
Returns the variance.
var erlang = new Erlang( 4, 12.0 );
var s2 = erlang.variance;
// returns ~0.028
Evaluates the cumulative distribution function (CDF).
var erlang = new Erlang( 2, 4.0 );
var y = erlang.cdf( 0.5 );
// returns ~0.594
Evaluates the natural logarithm of the probability density function (PDF).
var erlang = new Erlang( 2, 4.0 );
var y = erlang.logpdf( 0.8 );
// returns ~-0.65
Evaluates the moment-generating function (MGF).
var erlang = new Erlang( 2, 4.0 );
var y = erlang.mgf( 0.5 );
// returns ~1.306
Evaluates the probability density function (PDF).
var erlang = new Erlang( 2, 4.0 );
var y = erlang.pdf( 0.8 );
// returns ~0.522
Evaluates the quantile function at probability p
.
var erlang = new Erlang( 2, 4.0 );
var y = erlang.quantile( 0.5 );
// returns ~0.42
y = erlang.quantile( 1.9 );
// returns NaN
var Erlang = require( '@stdlib/stats-base-dists-erlang-ctor' );
var erlang = new Erlang( 2, 4.0 );
var mu = erlang.mean;
// returns 0.5
var mode = erlang.mode;
// returns 0.25
var s2 = erlang.variance;
// returns 0.125
var y = erlang.cdf( 0.8 );
// returns ~0.829
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.
See LICENSE.
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