blas-dswap

    1.0.0 • Public • Published

    dswap

    NPM version Build Status Coverage Status Dependencies

    Interchanges the elements of x and y.

    Installation

    $ npm install blas-dswap

    Usage

    var swap = require( 'blas-dswap' );

    swap( N, x, strideX, offsetX, y, strideY, offsetY )

    Interchanges the elements of x and y.

    var x = [ 1, 2, 3, 4, 5 ];
    var y = [ 6, 7, 8, 9, 10 ];
     
    swap( x.length, x, 1, 0, y, 1, 0 );
    // x => [ 6, 7, 8, 9, 10 ]
    // y => [ 1, 2, 3, 4, 5 ]

    The function accepts the following parameters:

    • N: number of elements to swap.
    • x: input array or typed array.
    • strideX: index increment for x.
    • offsetX: starting index for x.
    • y: input array or typed array.
    • strideY: index increment for y.
    • offsetY: starting index for y.

    The N, stride, and offset parameters determine how elements are interchanged between x and y. For example, to swap every other element in x starting from its second element with the last N elements in y starting from its last element,

    var x = [ 1, 2, 3, 4, 5, 6 ];
    var y = [ 7, 8, 9, 10, 11, 12 ];
     
    var N = Math.floor( x.length / 2 );
     
    swap( N, x, 2, 1, y, -1, y.length-1 );
    // x => [ 1, 12, 3, 11, 5, 10 ]
    // y => [ 7, 8, 9, 6, 4, 2 ]

    If N <= 0, the function returns undefined.

    Notes

    • This module corresponds to the BLAS level 1 function dswap.

    Examples

    var swap = require( 'blas-dswap' );
     
    var x;
    var y;
    var i;
     
    = new Float64Array( 10 );
    = new Float64Array( 10 );
    for ( i = 0; i < x.length; i++ ) {
        x[ i ] = Math.round( Math.random()*500 );
        y[ i ] = Math.round( Math.random()*10 );
    }
    console.log( x );
    console.log( y );
     
    // Swap elements such that the element orders are reversed:
    swap( x.length, x, 1, 0, y, -1, y.length-1 );
     
    console.log( x );
    console.log( 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 blas-dswap

    DownloadsWeekly Downloads

    2

    Version

    1.0.0

    License

    MIT

    Last publish

    Collaborators

    • kgryte