Nebulous Pumpkin Moons

    compute-hamming

    1.1.0 • Public • Published

    Hamming Distance

    NPM version Build Status Coverage Status Dependencies

    Computes the Hamming distance between two sequences.

    In information theory, the Hamming distance is number of differences between two sequences of the same length. These sequences may be represented as character strings, binary strings, or arrays.

    Installation

    $ npm install compute-hamming

    For use in the browser, use browserify.

    Usage

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

    hamming( a, b[, accessor] )

    Computes the Hamming distance between two sequences. The sequences must be either both equal length strings or equal length arrays.

    var a = 'this is a string.',
        b = 'thiz iz a string.';
     
    var dist = hamming( a, b );
    // returns 2
     
    var c = [ 5, 23, 2, 5, 9 ],
        d = [ 3, 21, 2, 5, 14 ];
     
    dist = hamming( c, d );
    // returns 3

    To compute the Hamming distance between nested array values, provide an accessor function for accessing array values.

    var a = [
        {'x':2},
        {'x':4},
        {'x':5},
        {'x':3},
        {'x':8},
        {'x':2}
    ];
     
    var b = [
        [1,3],
        [2,1],
        [3,5],
        [4,3],
        [5,7],
        [6,2]
    ];
     
    function getValue( d, i, j ) {
        if ( j === 0 ) {
            return d.x;
        }
        return d[ 1 ];
    }
     
    var dist = hamming( a, b, getValue );
    // returns 3

    The accessor function is provided three arguments:

    • d: current datum.
    • i: current datum index.
    • j: sequence index; e.g., sequence a has index 0 and sequence b has index 1.

    Examples

    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 © 2014-2015. Athan Reines.

    Install

    npm i compute-hamming

    DownloadsWeekly Downloads

    348

    Version

    1.1.0

    License

    none

    Last publish

    Collaborators

    • kgryte
    • planeshifter