@stdlib/stats-base-dists-triangular-variance
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    0.0.6 • Public • Published

    Variance

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    Triangular distribution variance.

    The variance for a triangular random variable is

    Variance for a triangular distribution.

    where a is the lower limit, b is the upper limit and c is the mode.

    Installation

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

    Usage

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

    variance( a, b, c )

    Returns the variance of a triangular distribution with minimum support a, maximum supportb, and mode c.

    var v = variance( 0.0, 1.0, 0.8 );
    // returns ~0.047
    
    v = variance( 4.0, 12.0, 5.0 );
    // returns ~3.167
    
    v = variance( 2.0, 8.0, 5.0 );
    // returns 1.5

    If provided NaN as any argument, the function returns NaN.

    var v = variance( NaN, 4.0, 2.0 );
    // returns NaN
    
    v = variance( 0.0, NaN, 2.0 );
    // returns NaN
    
    v = variance( 0.0, 4.0, NaN );
    // returns NaN

    If provided parameters not satisfying a <= c <= b, the function returns NaN.

    var y = variance( 1.0, 0.0, 1.5 );
    // returns NaN
    
    y = variance( 0.0, 1.0, -1.0 );
    // returns NaN
    
    y = variance( 0.0, -1.0, 0.5 );
    // returns NaN

    Examples

    var randu = require( '@stdlib/random-base-randu' );
    var variance = require( '@stdlib/stats-base-dists-triangular-variance' );
    
    var a;
    var b;
    var c;
    var v;
    var i;
    
    for ( i = 0; i < 10; i++ ) {
        a = ( randu()*10.0 );
        b = ( randu()*10.0 ) + a;
        c = ( randu()*( b-a ) ) + a;
        v = variance( a, b, c );
        console.log( 'a: %d, b: %d, c: %d, Var(X;a,b,c): %d', a.toFixed( 4 ), b.toFixed( 4 ), c.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 © 2016-2021. The Stdlib Authors.

    Install

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

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    12

    Version

    0.0.6

    License

    Apache-2.0

    Unpacked Size

    48.5 kB

    Total Files

    10

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser