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Logistic
Logistic distribution constructor.
Installation
npm install @stdlib/stats-base-dists-logistic-ctor
Usage
var Logistic = require( '@stdlib/stats-base-dists-logistic-ctor' );
Logistic( [mu, s] )
Returns a logistic distribution object.
var logistic = new Logistic();
var mu = logistic.mean;
// returns 0.0
By default, mu = 0.0
and s = 1.0
. To create a distribution having a different mu
(location parameter) and s
(scale parameter), provide the corresponding arguments.
var logistic = new Logistic( 2.0, 4.0 );
var mu = logistic.mean;
// returns 2.0
logistic
A logistic distribution object has the following properties and methods...
Writable Properties
logistic.mu
Location parameter of the distribution.
var logistic = new Logistic();
var mu = logistic.mu;
// returns 0.0
logistic.mu = 3.0;
mu = logistic.mu;
// returns 3.0
logistic.s
Scale parameter of the distribution. s
must be a positive number.
var logistic = new Logistic( 2.0, 4.0 );
var s = logistic.s;
// returns 4.0
logistic.s = 3.0;
s = logistic.s;
// returns 3.0
Computed Properties
Logistic.prototype.entropy
Returns the differential entropy.
var logistic = new Logistic( 4.0, 12.0 );
var entropy = logistic.entropy;
// returns ~4.485
Logistic.prototype.kurtosis
Returns the excess kurtosis.
var logistic = new Logistic( 4.0, 12.0 );
var kurtosis = logistic.kurtosis;
// returns 1.2
Logistic.prototype.mean
Returns the expected value.
var logistic = new Logistic( 4.0, 12.0 );
var mu = logistic.mean;
// returns 4.0
Logistic.prototype.median
Returns the median.
var logistic = new Logistic( 4.0, 12.0 );
var median = logistic.median;
// returns 4.0
Logistic.prototype.mode
Returns the mode.
var logistic = new Logistic( 4.0, 12.0 );
var mode = logistic.mode;
// returns 4.0
Logistic.prototype.skewness
Returns the skewness.
var logistic = new Logistic( 4.0, 12.0 );
var skewness = logistic.skewness;
// returns 0.0
Logistic.prototype.stdev
Returns the standard deviation.
var logistic = new Logistic( 4.0, 12.0 );
var s = logistic.stdev;
// returns ~21.766
Logistic.prototype.variance
Returns the variance.
var logistic = new Logistic( 4.0, 12.0 );
var s2 = logistic.variance;
// returns ~473.741
Methods
Logistic.prototype.cdf( x )
Evaluates the cumulative distribution function (CDF).
var logistic = new Logistic( 2.0, 4.0 );
var y = logistic.cdf( 0.5 );
// returns ~0.407
Logistic.prototype.logcdf( x )
Evaluates the natural logarithm of the cumulative distribution function (CDF).
var logistic = new Logistic( 2.0, 4.0 );
var y = logistic.logcdf( 2.0 );
// returns ~-0.693
Logistic.prototype.logpdf( x )
Evaluates the natural logarithm of the probability density function (PDF).
var logistic = new Logistic( 2.0, 4.0 );
var y = logistic.logpdf( 0.8 );
// returns ~-2.795
Logistic.prototype.mgf( t )
Evaluates the moment-generating function (MGF).
var logistic = new Logistic( 2.0, 4.0 );
var y = logistic.mgf( 0.2 );
// returns ~6.379
Logistic.prototype.pdf( x )
Evaluates the probability density function (PDF).
var logistic = new Logistic( 2.0, 4.0 );
var y = logistic.pdf( 2.0 );
// returns 0.0625
Logistic.prototype.quantile( p )
Evaluates the quantile function at probability p
.
var logistic = new Logistic( 2.0, 4.0 );
var y = logistic.quantile( 0.5 );
// returns 2.0
y = logistic.quantile( 1.9 );
// returns NaN
Examples
var Logistic = require( '@stdlib/stats-base-dists-logistic-ctor' );
var logistic = new Logistic( 2.0, 4.0 );
var mean = logistic.mean;
// returns 2.0
var median = logistic.median;
// returns 2.0
var s2 = logistic.variance;
// returns ~52.638
var y = logistic.cdf( 0.8 );
// returns ~0.426
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.