# floorn

Round a numeric value to the nearest multiple of 10^n toward negative infinity.

## Usage

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

#### floorn( x, n )

Rounds a `numeric` value to the nearest multiple of `10^n` toward negative infinity.

``````// Round a value to 4 decimal places:
var v = floorn( Math.PI, -4 );
// returns 3.1415

// If n = 0, `floorn` behaves like `floor`:
v = floorn( Math.PI, 0 );
// returns 3.0

// Round a value to the nearest thousand:
v = floorn( 12368.0, 3 );
// returns 12000.0
``````

## Notes

• When operating on floating-point numbers in bases other than `2`, rounding to specified digits can be inexact. For example,

``````var x = -0.2 - 0.1;
// returns -0.30000000000000004

// Should round to -0.3:
var v = floorn( x, -16 );
// returns -0.3000000000000001
``````

## Examples

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

var x;
var n;
var v;
var i;

for ( i = 0; i < 100; i++ ) {
x = (randu()*100.0) - 50.0;
n = floorn( randu()*5.0, 0 );
v = floorn( x, -n );
console.log( 'x: %d. Number of decimals: %d. Rounded: %d.', x, n, v );
}
``````