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scattered

Scatter a list of provided values to specified indices in a new zero-filled "generic" array.

Installation

npm install @stdlib/array-base-scattered

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

scattered( len, indices, values, mode )

Scatters a list of provided values to specified indices in a new zero-filled "generic" array.

var out = scattered( 4, [ 1, 3 ], [ 20, 40 ], 'throw' );
// returns [ 0, 20, 0, 40 ]

The function supports the following parameters:

• len: output array length.
• indices: list of indices.
• values: values to scatter. When indices contains one or more elements, values must be broadcast compatible with indices (i.e., must have either one element or the same number of elements as indices).
• mode: index mode.

If indices is an empty array, the function returns a zero-filled array.

var out = scattered( 4, [], [ 20, 40 ], 'throw' );
// returns [ 0, 0, 0, 0 ]

The function supports broadcasting a values array containing a single element against an indices array containing one or more elements.

var out = scattered( 4, [ 1, 3 ], [ 20 ], 'throw' );
// returns [ 0, 20, 0, 20 ]

Examples

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

// Generate an array of random indices:
var N = discreteUniform( 5, 15 );
var indices = filledBy( N, discreteUniform.factory( 0, 10 ) );
console.log( indices );

// Generate an array of random values:
var values = filledBy( N, discreteUniform.factory( 1000, 2025 ) );
console.log( values );

// Scatter a random sample of elements to a new array:
var out = scattered( 11, indices, values, 'throw' );
console.log( out );

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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 © 2016-2025. The Stdlib Authors.