npm package: @stdlib/math-base-special-round-nearest-even
Description: Round a double-precision floating-point number to the nearest integer value with ties rounding to the nearest even integer.
Author: The Stdlib Authors
Latest version: 0.1.1

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# roundNearestEven

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Round a double-precision floating-point number to the nearest integer value with ties rounding to the nearest even integer.

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-special-round-nearest-even
```

</section>

<section class="usage">

## Usage

```javascript
var roundNearestEven = require( '@stdlib/math-base-special-round-nearest-even' );
```

#### roundNearestEven( x )

Rounds a double-precision floating-point number to the nearest integer value with ties rounding to the nearest even integer.

```javascript
var v = roundNearestEven( -3.5 );
// returns -4.0

v = roundNearestEven( -4.2 );
// returns -4.0

v = roundNearestEven( -4.5 );
// returns -4.0

v = roundNearestEven( -4.6 );
// returns -5.0

v = roundNearestEven( 9.99999 );
// returns 10.0

v = roundNearestEven( 8.5 );
// returns 8.0

v = roundNearestEven( 9.5 );
// returns 10.0

v = roundNearestEven( 9.2 );
// returns 9.0

v = roundNearestEven( 0.0 );
// returns 0.0

v = roundNearestEven( -0.0 );
// returns -0.0

v = roundNearestEven( Infinity );
// returns Infinity

v = roundNearestEven( -Infinity );
// returns -Infinity

v = roundNearestEven( NaN );
// returns NaN
```

</section>

<!-- /.usage -->

<section class="notes">

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var roundNearestEven = require( '@stdlib/math-base-special-round-nearest-even' );

var opts = {
    'dtype': 'float64'
};
var x = uniform( 100, -50.0, 50.0, opts );

logEachMap( 'roundNearestEven(%.4f) = %.4f', x, roundNearestEven );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/math/base/special/round_nearest_even.h"
```

#### stdlib_base_round_nearest_even( x )

Rounds a double-precision floating-point number to the nearest integer value with ties rounding to the nearest even integer.

```c
double out = stdlib_base_round_nearest_even( -4.5 );
// returns -4.0
```

The function accepts the following arguments:

-   **x**: `[in] double` input value.

```c
double stdlib_base_round_nearest_even( const double x );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/math/base/special/round_nearest_even.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { -5.0, -3.89, -2.78, -1.67, -0.50, 0.50, 1.67, 2.78, 3.89, 5.0 };

    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_round_nearest_even( x[ i ] );
        printf( "roundNearestEven(%lf) = %lf\n", x[ i ], v );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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<section class="related">

</section>

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<section class="main-repo" >

* * *

## 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].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

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

</section>

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