trunc2

Round a numeric value to the nearest power of two toward zero.

Installation

npm install @stdlib/math-base-special-trunc2

Usage

var trunc2 = require( '@stdlib/math-base-special-trunc2' );

trunc2( x )

Rounds a numeric value to the nearest power of two toward zero.

var v = trunc2( -4.2 );
// returns -4.0

v = trunc2( -4.5 );
// returns -4.0

v = trunc2( -4.6 );
// returns -4.0

v = trunc2( 9.99999 );
// returns 8.0

v = trunc2( 9.5 );
// returns 8.0

v = trunc2( 13.0 );
// returns 8.0

v = trunc2( -13.0 );
// returns -8.0

v = trunc2( 0.0 );
// returns 0.0

v = trunc2( -0.0 );
// returns -0.0

v = trunc2( Infinity );
// returns Infinity

v = trunc2( -Infinity );
// returns -Infinity

v = trunc2( NaN );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var trunc2 = require( '@stdlib/math-base-special-trunc2' );

var x;
var v;
var i;

for ( i = 0; i < 100; i++ ) {
    x = (randu()*100.0) - 50.0;
    v = trunc2( x );
    console.log( 'Value: %d. Rounded: %d.', x, v );
}

C APIs

Usage

#include "stdlib/math/base/special/trunc2.h"

stdlib_base_trunc2( x )

Rounds a numeric value to the nearest power of two toward zero.

double y = stdlib_base_trunc2( -4.2 );
// returns -4.0

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_trunc2( const double x );

Examples

#include "stdlib/math/base/special/trunc2.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_trunc2( x[ i ] );
        printf( "trunc2(%lf) = %lf\n", x[ i ], y );
    }
}

See Also

• @stdlib/math-base/special/ceil2: round a numeric value to the nearest power of two toward positive infinity.
• @stdlib/math-base/special/floor2: round a numeric value to the nearest power of two toward negative infinity.
• @stdlib/math-base/special/round2: round a numeric value to the nearest power of two on a linear scale.
• @stdlib/math-base/special/trunc: round a double-precision floating-point number toward zero.
• @stdlib/math-base/special/trunc10: round a numeric value to the nearest power of 10 toward zero.

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 © 2016-2024. The Stdlib Authors.