roundNearestEven

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

Installation

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

Usage

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.

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

Examples

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 );

C APIs

Usage

#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.

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

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_round_nearest_even( const double x );

Examples

#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 );
    }
}

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 © 2016-2026. The Stdlib Authors.