@stdlib/stats-base-dists-poisson-variance
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    0.0.8 • Public • Published

    Variance

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    Poisson distribution variance.

    The variance for a Poisson random variable is

    Variance for a Poisson distribution.

    where λ is the mean parameter.

    Installation

    npm install @stdlib/stats-base-dists-poisson-variance

    Usage

    var variance = require( '@stdlib/stats-base-dists-poisson-variance' );

    variance( lambda )

    Returns the variance of a Poisson distribution with mean parameter lambda.

    var v = variance( 9.0 );
    // returns 9.0
    
    v = variance( 0.5 );
    // returns 0.5

    If provided lambda < 0, the function returns NaN.

    var v = variance( -1.0 );
    // returns NaN

    Examples

    var randu = require( '@stdlib/random-base-randu' );
    var round = require( '@stdlib/math-base-special-round' );
    var variance = require( '@stdlib/stats-base-dists-poisson-variance' );
    
    var lambda;
    var v;
    var i;
    
    for ( i = 0; i < 10; i++ ) {
        lambda = randu() * 20.0;
        v = variance( lambda );
        console.log( 'λ: %d, Var(X;λ): %d', lambda.toFixed( 4 ), v.toFixed( 4 ) );
    }

    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.

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    License

    See LICENSE.

    Copyright

    Copyright © 2016-2022. The Stdlib Authors.

    Install

    npm i @stdlib/stats-base-dists-poisson-variance

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    108

    Version

    0.0.8

    License

    Apache-2.0

    Unpacked Size

    28.6 kB

    Total Files

    10

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    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser