Truncate

Round a double-precision floating-point number toward zero.

Usage

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

trunc( x )

Rounds a double-precision floating-point number toward zero.

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

v = trunc( 9.99999 );
// returns 9.0

v = trunc( 0.0 );
// returns 0.0

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

v = trunc( NaN );
// returns NaN

v = trunc( Infinity );
// returns Infinity

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

Examples

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

var x;
var i;

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

C APIs

Usage

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

stdlib_base_trunc( x )

Rounds a double-precision floating-point number toward zero.

double y = stdlib_base_trunc( 3.14 );
// returns 3.0

The function accepts the following arguments:

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

Examples

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

int main( void ) {
    const double x[] = { 3.14, -3.14, 0.0, 0.0/0.0 };

    double y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_trunc( x[ i ] );
        printf( "trunc(%lf) = %lf\n", x[ i ], y );
    }
}
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