npm package: @stdlib/array-base-bifurcate-indices
Description: Split array element indices into two groups.
Author: The Stdlib Authors
Latest version: 0.2.3

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# bifurcateIndices

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> Split array element indices into two groups.

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<section class="intro">

</section>

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<section class="installation">

## Installation

```bash
npm install @stdlib/array-base-bifurcate-indices
```

</section>

<section class="usage">

## Usage

```javascript
var bifurcateIndices = require( '@stdlib/array-base-bifurcate-indices' );
```

#### bifurcateIndices( x, filter )

Splits array element indices into two groups.

```javascript
var x = [ 'beep', 'boop', 'foo', 'bar' ];
var filter = [ true, true, false, true ];

var out = bifurcateIndices( x, filter );
// returns [ [ 0, 1, 3 ], [ 2 ] ]
```

</section>

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<section class="notes">

## Notes

-   If an element in `filter` is truthy, the corresponding element in the input array `x` belongs to the first group; otherwise, the input array element belongs to the second group.

</section>

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<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var take = require( '@stdlib/array-base-take-indexed' );
var bifurcateIndices = require( '@stdlib/array-base-bifurcate-indices' );

// Define an initial array of values:
var values = [ 'beep', 'boop', 'foo', 'bar', 'woot', 'woot' ];

// Sample from the initial array to generate a random collection:
var indices = discreteUniform( 100, 0, values.length-1, {
    'dtype': 'generic'
});
var x = take( values, indices );
// returns [...]

// Randomly assign collection values to groups:
var groups = discreteUniform( x.length, 0, 1, {
    'dtype': 'generic'
});

// Group the values:
var out = bifurcateIndices( x, groups );
// returns [...]

console.log( out );
```

</section>

<!-- /.examples -->

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* * *

## Notice

This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].

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---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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