take

Take elements from an array.

Installation

npm install @stdlib/array-base-take

Usage

var take = require( '@stdlib/array-base-take' );

take( x, indices, mode )

Takes elements from an array.

var x = [ 1, 2, 3, 4 ];

var y = take( x, [ 1, 3 ], 'throw' );
// returns [ 2, 4 ]

The function supports the following parameters:

• x: input array.
• indices: list of indices.
• mode: index mode.

If indices is an empty array, the function returns an empty array.

var x = [ 1, 2, 3, 4 ];

var y = take( x, [], 'throw' );
// returns []

take.assign( x, indices, mode, out, stride, offset )

Takes elements from an array and assigns the values to elements in a provided output array.

var x = [ 1, 2, 3, 4 ];

var out = [ 0, 0, 0, 0, 0, 0 ];
var indices = [ 0, 0, 1, 1, 3, 3 ];

var arr = take.assign( x, indices, 'throw', out, -1, out.length-1 );
// returns [ 4, 4, 2, 2, 1, 1 ]

var bool = ( arr === out );
// returns true

The function supports the following parameters:

• x: input array.
• indices: list of indices.
• mode: index mode.
• out: output array.
• stride: output array stride.
• offset: output array offset.

Examples

var filledBy = require( '@stdlib/array-base-filled-by' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var linspace = require( '@stdlib/array-base-linspace' );
var take = require( '@stdlib/array-base-take' );

// Generate a linearly spaced array:
var x = linspace( 0, 100, 11 );
console.log( x );

// Generate an array of random indices:
var N = discreteUniform( 5, 15 );
var indices = filledBy( N, discreteUniform.factory( 0, x.length-1 ) );
console.log( indices );

// Take a random sample of elements from `x`:
var y = take( x, indices, 'throw' );
console.log( y );

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.