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    math-float64-copysign

    1.0.0 • Public • Published

    Copysign

    NPM version Build Status Coverage Status Dependencies

    Returns a double-precision floating-point number with the magnitude of x and the sign of y.

    Installation

    $ npm install math-float64-copysign

    Usage

    var copysign = require( 'math-float64-copysign' );

    copysign( x, y )

    Returns a double-precision floating-point number with the magnitude of x and the sign of y.

    var z = copysign( -3.14, 10 );
    // returns 3.14
     
    = copysign( 3.14, -1 );
    // returns -3.14
     
    = copysign( 1, -0 );
    // returns -1
     
    = copysign( -3.14, -0 );
    // returns -3.14
     
    = copysign( -0, 1 );
    // returns 0

    Notes

    • According to the IEEE754 standard, a NaN has a biased exponent equal to 2047, a significand greater than 0, and a sign bit equal to either 1 or 0. In which case, NaN may not correspond to just one but many binary representations. Accordingly, care should be taken to ensure that y is not NaN, else behavior may be indeterminate.

    Examples

    var copysign = require( 'math-float64-copysign' );
     
    var x;
    var y;
    var z;
    var i;
     
    // Generate random double-precision floating-point numbers `x` and `y` and copy the sign of `y` to `x`...
    for ( i = 0; i < 100; i++ ) {
        x = Math.random()*100 - 50;
        y = Math.random()*10 - 5;
        z = copysign( x, y );
        console.log( 'x: %d, y: %d => %d', x, y, z );
    }

    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-float64-copysign

    DownloadsWeekly Downloads

    830

    Version

    1.0.0

    License

    MIT

    Last publish

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