stdlib-js / ndarray-base-to-array

Convert an ndarray buffer to a generic array.

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ndarray2array

Convert an ndarray buffer to a generic array.

Installation

npm install @stdlib/ndarray-base-to-array

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var ndarray2array = require( '@stdlib/ndarray-base-to-array' );

ndarray2array( buffer, shape, strides, offset, order )

Converts an ndarray buffer to a generic array (which may include nested arrays).

var buffer = [ 1, 2, 3, 4 ];
var shape = [ 2, 2 ];
var order = 'row-major';
var strides = [ 2, 1 ];
var offset = 0;

var arr = ndarray2array( buffer, shape, strides, offset, order );
// returns [ [ 1, 2 ], [ 3, 4 ] ]

The order parameter specifies whether an array is row-major (C-style) or column-major (Fortran-style).

var buffer = [ 1, 2, 3, 4 ];
var shape = [ 2, 2 ];
var order = 'column-major';
var strides = [ 1, 2 ];
var offset = 0;

var arr = ndarray2array( buffer, shape, strides, offset, order );
// returns [ [ 1, 3 ], [ 2, 4 ] ]

The offset parameter specifies the location of the first indexed element based on the strides array.

var buffer = [ 1, 2, 3, 4 ];
var shape = [ 2, 2 ];
var order = 'row-major';
var strides = [ -2, -1 ];
var offset = 3;

var arr = ndarray2array( buffer, shape, strides, offset, order );
// returns [ [ 4, 3 ], [ 2, 1 ] ]

Examples

var shape2strides = require( '@stdlib/ndarray-base-shape2strides' );
var strides2offset = require( '@stdlib/ndarray-base-strides2offset' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var ndarray2array = require( '@stdlib/ndarray-base-to-array' );

// Create a data buffer:
var buffer = [];
var i;
for ( i = 0; i < 27; i++ ) {
    buffer.push( i );
}

// Specify array meta data:
var shape = [ 3, 3, 3 ];
var order = 'column-major';
var ndims = shape.length;

// Compute array meta data:
var strides = shape2strides( shape, order );
var offset = strides2offset( shape, strides );

// Print array information:
console.log( '' );
console.log( 'Dims: %s', shape.join( 'x' ) );

// Randomly flip strides and convert an ndarray to a nested array...
var arr;
var j;
for ( i = 0; i < 20; i++ ) {
    j = discreteUniform( 0, ndims-1 );
    strides[ j ] *= -1;
    offset = strides2offset( shape, strides );

    console.log( '' );
    console.log( 'Strides: %s', strides.join( ',' ) );
    console.log( 'Offset: %d', offset );

    arr = ndarray2array( buffer, shape, strides, offset, order );
    console.log( JSON.stringify( arr ) );
}

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Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.