math-powm1

    1.0.0 • Public • Published

    powm1

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    Computes bˣ - 1.

    Exponential function minus one.

    When b is close to 1 and/or x is small, this implementation is more accurate than naively computing minus 1.

    Installation

    $ npm install math-powm1

    Usage

    var powm1 = require( 'math-powm1' );

    powm1( b, x )

    Computes bˣ - 1.

    var y = powm1( 2, 3 );
    // returns 7
     
    = powm1( 4, 0.5 );
    // returns 1
     
    = powm1( 0, 100 );
    // returns -1
     
    = powm1( 100, 0 );
    // returns 0
     
    = powm1( 0, 0 );
    // returns 0
     
    = powm1( Math.PI, 5 );
    // returns ~305.0197
     
    = powm1( NaN, 3 );
    // returns NaN
     
    = powm1( 5, NaN );
    // returns NaN

    Examples

    var powm1 = require( 'math-powm1' );
     
    var b;
    var x;
    var y;
    var i;
     
    for ( i = 0; i < 100; i++ ) {
        b = Math.round( Math.random()*10 );
        x = Math.round( Math.random()*10 ) - 5;
        y = powm1( b, x );
        console.log( '%d^%d - 1 = %d', b, x, y );
    }

    To run the example code from the top-level application directory,

    $ node ./examples/index.js

    Tests

    Unit

    This repository uses tape for unit tests. To run the tests, execute the following command in the top-level application directory:

    $ make test

    All new feature development should have corresponding unit tests to validate correct functionality.

    Test Coverage

    This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:

    $ make test-cov

    Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

    $ make view-cov

    Browser Support

    This repository uses Testling for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:

    $ make test-browsers

    To view the tests in a local web browser,

    $ make view-browser-tests

    License

    MIT license.

    Copyright

    Copyright © 2016. The Compute.io Authors.

    Install

    npm i math-powm1

    DownloadsWeekly Downloads

    3

    Version

    1.0.0

    License

    MIT

    Last publish

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