reverse

Return a view of an input ndarray in which the order of elements along each dimension is reversed.

Installation

npm install @stdlib/ndarray-base-reverse

Usage

var reverse = require( '@stdlib/ndarray-base-reverse' );

reverse( x, writable )

Returns a view of an input ndarray in which the order of elements along each dimension is reversed.

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

var buffer = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ];
var shape = [ 3, 2 ];
var strides = [ 2, 1 ];
var offset = 0;

var x = ndarray( 'generic', buffer, shape, strides, offset, 'row-major' );
// returns <ndarray>

var sh = x.shape;
// returns [ 3, 2 ]

var arr = ndarray2array( x );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ], [ 5.0, 6.0 ] ]

var y = reverse( x, false );
// returns <ndarray>

sh = y.shape;
// returns [ 3, 2 ]

arr = ndarray2array( y );
// returns [ [ 6.0, 5.0 ], [ 4.0, 3.0 ], [ 2.0, 1.0 ] ]

The function accepts the following arguments:

• x: input ndarray.
• writable: boolean indicating whether a returned ndarray should be writable.

Notes

• The writable parameter only applies to ndarray constructors supporting read-only instances.

Examples

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

// Create a linear ndarray buffer:
var buf = zeroTo( 16 );

// Create a one-dimensional ndarray:
var x1 = array( buf, {
    'shape': [ 16 ]
});

// Reverse element order:
var y1 = reverse( x1, false );
// returns <ndarray>

var a1 = ndarray2array( y1 );
// returns [ 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 ]

// Create a two-dimensional ndarray:
var x2 = array( buf, {
    'shape': [ 4, 4 ]
});

// Reverse element order:
var y2 = reverse( x2, false );
// returns <ndarray>

var a2 = ndarray2array( y2 );
// returns [ [ 15, 14, 13, 12 ], [ 11, 10, 9, 8 ], [ 7, 6, 5, 4 ], [ 3, 2, 1, 0 ] ]

// Create a three-dimensional ndarray:
var x3 = array( buf, {
    'shape': [ 2, 4, 2 ]
});

// Reverse element order:
var y3 = reverse( x3, false );
// returns <ndarray>

var a3 = ndarray2array( y3 );
// returns [ [ [ 15, 14 ], [ 13, 12 ], [ 11, 10 ], [ 9, 8 ] ], [ [ 7, 6 ], [ 5, 4 ], [ 3, 2 ], [ 1, 0 ] ] ]

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

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.