truncn

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

Usage

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

truncn( x, n )

Rounds a numeric value to the nearest multiple of 10^n toward zero.

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

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

// Round a value to the nearest thousand:
v = truncn( 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.

Examples

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

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

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