@stdlib/math-base-special-binomcoef
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    0.0.7 • Public • Published

    Binomial Coefficient

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    Compute the binomial coefficient.

    The binomial coefficient of two nonnegative integers n and k is defined as

    Factorial formula for the Binomial coefficient.

    The binomial coefficient can be generalized to negative integers n as follows:

    Generalization of the binomial coefficient to negative n.

    Installation

    npm install @stdlib/math-base-special-binomcoef

    Usage

    var binomcoef = require( '@stdlib/math-base-special-binomcoef' );

    binomcoef( n, k )

    Evaluates the binomial coefficient of two integers n and k.

    var v = binomcoef( 8, 2 );
    // returns 28
    
    v = binomcoef( 0, 0 );
    // returns 1
    
    v = binomcoef( -4, 2 );
    // returns 10
    
    v = binomcoef( 5, 3 );
    // returns 10
    
    v = binomcoef( NaN, 3 );
    // returns NaN
    
    v = binomcoef( 5, NaN );
    // returns NaN
    
    v = binomcoef( NaN, NaN );
    // returns NaN

    For negative k, the function returns 0.

    var v = binomcoef( 2, -1 );
    // returns 0
    
    v = binomcoef( -3, -1 );
    // returns 0

    The function returns NaN for non-integer n or k.

    var v = binomcoef( 2, 1.5 );
    // returns NaN
    
    v = binomcoef( 5.5, 2 );
    // returns NaN

    Examples

    var randu = require( '@stdlib/random-base-randu' );
    var round = require( '@stdlib/math-base-special-round' );
    var binomcoef = require( '@stdlib/math-base-special-binomcoef' );
    
    var n;
    var k;
    var i;
    
    for ( i = 0; i < 100; i++ ) {
        n = round( (randu()*30.0) - 10.0 );
        k = round( randu()*20.0 );
        console.log( '%d choose %d = %d', n, k, binomcoef( n, k ) );
    }

    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-binomcoef

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    450

    Version

    0.0.7

    License

    Apache-2.0

    Unpacked Size

    53.9 kB

    Total Files

    11

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser