@stdlib/math-base-special-truncn NPM

truncn

$NPM version$ $Build Status$ $Coverage Status$

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

Installation

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

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( 3.141592653589793, -4 );
// returns 3.1415

// If n = 0, `truncn` behaves like `trunc`:
v = truncn( 3.141592653589793, 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 );
}

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.