@stdlib/math-base-special-kernel-betainc
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    0.0.5 • Public • Published

    Kernel Betainc

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    Incomplete beta function and its first derivative.

    Installation

    npm install @stdlib/math-base-special-kernel-betainc

    Usage

    var kernelBetainc = require( '@stdlib/math-base-special-kernel-betainc' );

    kernelBetainc( x, a, b, regularized, upper )

    Evaluates the incomplete beta function and its first derivative for parameters x, a > 0 and b > 0. The regularized and upper boolean parameters are used to specify whether to evaluate the regularized or non-regularized and the upper or lower incomplete beta functions, respectively.

    var out = kernelBetainc( 0.8, 1.0, 0.3, false, false );
    // returns [ ~1.277, ~0.926 ]
    
    out = kernelBetainc( 0.2, 1.0, 2.0, true, false );
    // returns [ 0.36, 1.6 ]
    
    out = kernelBetainc( 0.2, 1.0, 2.0, true, true );
    // returns [ 0.64, 1.6 ]

    If provided NaN for x, a, or b, the function returns [ NaN, NaN ].

    var out = kernelBetainc( NaN, 1.0, 1.0, true, true );
    // returns [ NaN, NaN ]
    
    out = kernelBetainc( 0.8, NaN, 1.0, true, true );
    // returns [ NaN, NaN ]
    
    out = kernelBetainc( 0.8, 1.0, NaN, true, true );
    // returns [ NaN, NaN ]

    If x is outside the interval [0,1], the function returns [ NaN, NaN ].

    var out = kernelBetainc( 1.5, 1.0, 1.0, true, true );
    // returns [ NaN, NaN ]
    
    out = kernelBetainc( -0.5, 1.0, 1.0, true, true );
    // returns [ NaN, NaN ]

    If a or b is negative, the function returns [ NaN, NaN ].

    var out = kernelBetainc( 0.5, -2.0, 2.0, true, true );
    // returns [ NaN, NaN ]
    
    out = kernelBetainc( 0.5, 2.0, -2.0, true, true );
    // returns [ NaN, NaN ]

    kernelBetainc.assign( x, a, b, regularized, upper, out, stride, offset )

    Evaluates the incomplete beta function and its first derivative for parameters x, a > 0 and b > 0 and assigns results to a provided output array.

    var Float64Array = require( '@stdlib/array-float64' );
    
    var out = new Float64Array( 2 );
    var v = kernelBetainc.assign( 0.2, 1.0, 2.0, true, true, out, 1, 0 );
    // returns <Float64Array>[ 0.64, 1.6 ]
    
    var bool = ( v === out );
    // returns true

    The offset parameter specifies the index of the first output array element, and the stride parameter specifies the stride length between consecutive output array elements.

    Examples

    var randu = require( '@stdlib/random-base-randu' );
    var kernelBetainc = require( '@stdlib/math-base-special-kernel-betainc' );
    
    var out;
    var i;
    var x;
    var a;
    var b;
    
    out = [ 0.0, 0.0 ];
    for ( i = 0; i < 100; i++ ) {
        x = randu();
        a = randu() * 10.0;
        b = randu() * 10.0;
        kernelBetainc( x, a, b, true, false, out, 1, 0 );
        console.log( 'x: %d, \t a: %d, \t b: %d, \t f(x,a,b): %d, \t f^1(x,a,b): %d', x.toFixed( 4 ), a.toFixed( 4 ), b.toFixed( 4 ), out[ 0 ].toFixed( 4 ), out[ 1 ].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/math-base-special-kernel-betainc

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    451

    Version

    0.0.5

    License

    Apache-2.0 AND BSL-1.0

    Unpacked Size

    105 kB

    Total Files

    23

    Last publish

    Collaborators

    • stdlib-bot
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    • planeshifter
    • rreusser