Round

Round a numeric value to the nearest integer.

Usage

var round = require( '@stdlib/math/base/special/round' );

round( x )

Rounds a numeric value to the nearest integer.

var v = round( -4.2 );
// returns -4.0

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

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

v = round( 9.99999 );
// returns 10.0

v = round( 9.5 );
// returns 10.0

v = round( 9.2 );
// returns 9.0

v = round( 0.0 );
// returns 0.0

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

v = round( Infinity );
// returns Infinity

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

v = round( NaN );
// returns NaN

Notes

  • Ties are rounded toward positive infinity.

Examples

var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );

var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = (randu()*100.0) - 50.0;
    console.log( 'Value: %d. Rounded: %d.', x, round( x ) );
}

C APIs

Usage

#include "stdlib/math/base/special/round.h"

stdlib_base_round( x )

Rounds a numeric value to the nearest integer.

double out = stdlib_base_round( -4.2 );
// returns -4.0

The function accepts the following arguments:

  • x: [in] double input value.
double stdlib_base_round( const double x );

Examples

#include "stdlib/math/base/special/round.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { -5.0, -3.89, -2.78, -1.67, -0.56, 0.56, 1.67, 2.78, 3.89, 5.0 };
    
    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_round( x[ i ] );
        printf( "round(%lf) = %lf\n", x[ i ], v );
    }
}
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