floor10

Round a numeric value to the nearest power of 10 toward negative infinity.

Installation

npm install @stdlib/math-base-special-floor10

Usage

var floor10 = require( '@stdlib/math-base-special-floor10' );

floor10( x )

Rounds a numeric value to the nearest power of 10 toward negative infinity.

var v = floor10( -4.2 );
// returns -10.0

v = floor10( -4.5 );
// returns -10.0

v = floor10( -4.6 );
// returns -10.0

v = floor10( 9.99999 );
// returns 1.0

v = floor10( 9.5 );
// returns 1.0

v = floor10( 13.0 );
// returns 10.0

v = floor10( -13.0 );
// returns -100.0

v = floor10( 0.0 );
// returns 0.0

v = floor10( -0.0 );
// returns -0.0

v = floor10( Infinity );
// returns Infinity

v = floor10( -Infinity );
// returns -Infinity

v = floor10( NaN );
// returns NaN

Notes

• The function may not return accurate results for subnormals due to a general loss in precision.

  var v = floor10( 1.0e-323 ); // should return 1.0e-323
  // returns 0.0

Examples

var randu = require( '@stdlib/random-base-randu' );
var floor10 = require( '@stdlib/math-base-special-floor10' );

var x;
var v;
var i;

for ( i = 0; i < 100; i++ ) {
    x = (randu()*100.0) - 50.0;
    v = floor10( x );
    console.log( 'Value: %d. Rounded: %d.', x, v );
}

C APIs

Usage

#include "stdlib/math/base/special/floor10.h"

stdlib_base_floor10( x )

Rounds a numeric value to the nearest power of 10 toward negative infinity.

double y = stdlib_base_floor10( -4.2 );
// returns -10.0

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_floor10( const double x );

Examples

#include "stdlib/math/base/special/floor10.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 3.14, -3.14, 0.0, 9.0 / 0.0 };

    double y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_floor10( x[ i ] );
        printf( "floor10(%lf) = %lf\n", x[ i ], y );
    }
}

See Also

• @stdlib/math-base/special/ceil10: round a numeric value to the nearest power of 10 toward positive infinity.
• @stdlib/math-base/special/floor: round a double-precision floating-point number toward negative infinity.
• @stdlib/math-base/special/floor2: round a numeric value to the nearest power of two toward negative infinity.
• @stdlib/math-base/special/round10: round a numeric value to the nearest power of 10 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.