floor2

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

Installation

npm install @stdlib/math-base-special-floor2

Usage

var floor2 = require( '@stdlib/math-base-special-floor2' );

floor2( x )

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

var v = floor2( -4.2 );
// returns -8.0

v = floor2( -4.5 );
// returns -8.0

v = floor2( -4.6 );
// returns -8.0

v = floor2( 9.99999 );
// returns 8.0

v = floor2( 9.5 );
// returns 8.0

v = floor2( 13.0 );
// returns 8.0

v = floor2( -13.0 );
// returns -16.0

v = floor2( 0.0 );
// returns 0.0

v = floor2( -0.0 );
// returns -0.0

v = floor2( Infinity );
// returns Infinity

v = floor2( -Infinity );
// returns -Infinity

v = floor2( NaN );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var floor2 = require( '@stdlib/math-base-special-floor2' );

var x;
var v;
var i;

for ( i = 0; i < 100; i++ ) {
    x = (randu()*100.0) - 50.0;
    v = floor2( x );
    console.log( 'Value: %d. Rounded: %d.', x, v );
}

C APIs

Usage

#include "stdlib/math/base/special/floor2.h"

stdlib_base_floor2( x )

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

double y = stdlib_base_floor2( -4.2 );
// returns -8.0

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_floor2( const double x );

Examples

#include "stdlib/math/base/special/floor2.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_floor2( x[ i ] );
        printf( "floor2(%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/floor: round a double-precision floating-point number toward negative infinity.
• @stdlib/math-base/special/floor10: round a numeric value to the nearest power of 10 toward negative infinity.
• @stdlib/math-base/special/round2: round a numeric value to the nearest power of two on a linear scale.

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.