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    @stdlib/math-base-special-expm1rel
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    0.0.5 • Public • Published

    expm1rel

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    Compute the relative error exponential.

    The relative error exponential is defined as

    Equation for the relative error exponential.

    Installation

    npm install @stdlib/math-base-special-expm1rel

    Usage

    var expm1rel = require( '@stdlib/math-base-special-expm1rel' );

    expm1rel( x )

    Computes the relative error exponential.

    var v = expm1rel( 0.0 );
    // returns 1.0
    
    v = expm1rel( 1.0 );
    // returns ~1.718
    
    v = expm1rel( -1.0 );
    // returns ~0.632
    
    v = expm1rel( NaN );
    // returns NaN

    Notes

    • When x is near zero, exp(x)-1 can suffer catastrophic cancellation (i.e., a significant loss in precision). expm1rel avoids such a loss in precision.

    Examples

    var randu = require( '@stdlib/random-base-randu' );
    var expm1rel = require( '@stdlib/math-base-special-expm1rel' );
    
    var x;
    var y;
    var a;
    var i;
    
    for ( i = 0; i < 100; i++ ) {
        x = (randu()*100.0) - 50.0;
        a = x.toFixed( 3 );
        y = expm1rel( x );
        console.log( '(e^%d - 1)/%d = %d', a, a, y );
    }

    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-expm1rel

    Homepage

    stdlib.io

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    9

    Version

    0.0.5

    License

    Apache-2.0

    Unpacked Size

    41.5 kB

    Total Files

    10

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    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser