November Perfect Moustache

    compute-divide

    2.0.0 • Public • Published

    Divide

    NPM version Build Status Coverage Status Dependencies

    Computes an element-wise division.

    Installation

    $ npm install compute-divide

    For use in the browser, use browserify.

    Usage

    var divide = require( 'compute-divide' );

    divide( arr, x[, opts] )

    Computes an element-wise division. x may be either an array of equal length or a numeric value.

    var arr = [ 2, 1, 4, 2 ],
        out;
     
    out = divide( arr, 2 );
    // returns [ 1, 0.5, 2, 1 ]
     
    out = divide( arr, [ 1, 2, 8, 8 ] );
    // returns [ 2, 1, 0.5, 0.25 ]

    The function accepts the following options:

    • copy: boolean indicating whether to return a new array. Default: true.
    • accessor: accessor function for accessing values in object arrays.

    To mutate the input array (e.g., when input values can be discarded or when optimizing memory usage), set the copy option to false.

    var arr = [ 5, 3, 8, 3, 2 ];
     
    var out = divide( arr, 4, {
        'copy': false
    });
    // returns [ 1.25, 0.75, 0.5, 0.75, 0.5 ]
     
    console.log( arr === out );
    // returns true

    Note: mutation is the array equivalent of a slash-equal (/=).

    For object arrays, provide an accessor function for accessing array values.

    var data = [
        ['beep', 5],
        ['boop', 3],
        ['bip', 8],
        ['bap', 3],
        ['baz', 2]
    ];
     
    function getValue( d, i ) {
        return d[ 1 ];
    }
     
    var out = divide( data, 4, {
        'accessor': getValue
    });
    // returns [ 1.25, 0.75, 2, 0.75, 0.5 ]

    When dividing values between two object arrays, provide an accessor function which accepts 3 arguments.

    var data = [
        ['beep', 5],
        ['boop', 3],
        ['bip', 8],
        ['bap', 3],
        ['baz', 2]
    ];
     
    var arr = [
        {'x': 4},
        {'x': 5},
        {'x': 6},
        {'x': 5},
        {'x': 3}
    ];
     
    function getValue( d, i, j ) {
        if ( j === 0 ) {
            return d[ 1 ];
        }
        return d.x;
    }
     
    var out = divide( data, arr, {
        'accessor': getValue
    });
    // returns [ 1.25, 0.6, ~1.33, 0.6, ~0.67 ]

    Note: j corresponds to the input array index, where j=0 is the index for the first input array and j=1 is the index for the second input array.

    Examples

    var divide = require( 'compute-divide' );
     
    var data = new Array( 100 );
    for ( var i = 0; i < data.length; i++ ) {
        data[ i ] = Math.round( Math.random()*100 );
    }
     
    var out = divide( data, 10 );
     
    console.log( out.join( '\n' ) );

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

    $ node ./examples/index.js

    Tests

    Unit

    Unit tests use the Mocha test framework with Chai assertions. 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

    License

    MIT license.

    Copyright

    Copyright © 2015. The Compute.io Authors.

    Install

    npm i compute-divide

    DownloadsWeekly Downloads

    319

    Version

    2.0.0

    License

    none

    Last publish

    Collaborators

    • kgryte