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

    Kernel Tangent

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    Compute the tangent of a number on [-π/4, π/4].

    Installation

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

    Usage

    var kernelTan = require( '@stdlib/math-base-special-kernel-tan' );

    kernelTan( x, y, k )

    Computes the tangent of a number on [-π/4, π/4]. For increased accuracy, the number for which the tangent should be evaluated can be supplied as a double-double number (i.e., a non-evaluated sum of two double-precision floating-point numbers x and y).

    var out = kernelTan( 3.141592653589793/4.0, 0.0, 1 );
    // returns ~1.0
    
    out = kernelTan( 3.141592653589793/6.0, 0.0, 1 );
    // returns ~0.577
    
    out = kernelTan( 0.664, 5.288e-17, 1 );
    // returns ~0.783

    If k = 1, the function returns tan(x+y). To return the negative inverse -1/tan(x+y), set k = -1.

    var out = kernelTan( 3.141592653589793/4.0, 0.0, -1 );
    // returns ~-1.0

    If either x or y is NaN, the function returns NaN.

    var out = kernelTan( NaN, 0.0, 1 );
    // returns NaN
    
    out = kernelTan( 3.0, NaN, 1 );
    // returns NaN
    
    out = kernelTan( NaN, NaN, 1 );
    // returns NaN

    Notes

    Examples

    var linspace = require( '@stdlib/array-linspace' );
    var binomial = require( '@stdlib/random-base-binomial' ).factory;
    var PI = require( '@stdlib/constants-float64-pi' );
    var kernelTan = require( '@stdlib/math-base-special-kernel-tan' );
    
    var x = linspace( -PI/4.0, PI/4.0, 100 );
    var rbinom = binomial( 1, 0.5 );
    
    var descr;
    var i;
    var k;
    
    for ( i = 0; i < x.length; i++ ) {
        k = rbinom();
        descr = ( k === 1 ) ? 'tan(%d) = %d' : '-1/tan(%d) = %d';
        console.log( descr, x[ i ], kernelTan( x[ i ], 0.0, 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-kernel-tan

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    2,558

    Version

    0.0.5

    License

    Apache-2.0

    Unpacked Size

    53 kB

    Total Files

    12

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
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    • rreusser