floor10

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

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 );
}