@stdlib/array/base/take2d/README.md

Arrays.

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# take2d

> Take elements from a two-dimensional nested array.

<section class="usage">

## Usage

```javascript
var take2d = require( '@stdlib/array/base/take2d' );
```

#### take2d( x, indices, dimension, mode )

Takes elements along a specified `dimension` from a two-dimensional nested array according to a specified [index `mode`][@stdlib/ndarray/index-modes].

```javascript
var x = [ [ 1, 2 ], [ 3, 4 ] ];
var indices = [ 1, 1, 0, 0, -1, -1 ];

var y = take2d( x, indices, 1, 'normalize' );
// returns [ [ 2, 2, 1, 1, 2, 2 ], [ 4, 4, 3, 3, 4, 4 ] ]
```

The function accepts the following arguments:

-   **x**: input nested array.
-   **indices**: list of indices.
-   **dimension**: dimension along which to take elements. If provided a negative integer, the dimension is resolved relative to the last dimension, with the last dimension being `-1`.
-   **mode**: [index mode][@stdlib/ndarray/index-modes] specifying how to handle an index which is out-of-bounds.

If `indices` is an empty array, the function returns empty arrays along the specified `dimension`.

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

var y = take2d( x, [], 1, 'throw' );
// returns [ [], [] ]

var z = take2d( x, [], 0, 'throw' );
// returns []
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   The function does **not** deep copy nested array elements.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var filled2dBy = require( '@stdlib/array/base/filled2d-by' );
var filledBy = require( '@stdlib/array/base/filled-by' );
var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
var take2d = require( '@stdlib/array/base/take2d' );

// Generate a random array:
var shape = [ 5, 5 ];
var x = filled2dBy( shape, discreteUniform.factory( 0, 100 ) );
console.log( x );

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

// Take a random sample of elements from `x`:
var y = take2d( x, indices, 1, 'throw' );
console.log( y );
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

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<section class="links">

[@stdlib/ndarray/index-modes]: https://www.npmjs.com/package/@stdlib/ndarray-index-modes

</section>

<!-- /.links -->