Round double to specified number of decimal places. - Java java.lang

Java examples for java.lang:double

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Description

Round double to specified number of decimal places.

Demo Code

/**   Basic numeric operations not included in standard Java run-time library.
 *
 *   <p>//from  www  .  j  av  a  2s. co  m
 *   The binomial methods are modified from those in the Colt library.
 *   </p>
 *
 *   <p>
 *   The following methods for trigonometric functions come from the
 *   Sfun class written by Visual Numerics.
 *   </p>
 *
 *   <ul>
 *   <li>acosh</li>
 *   <li>asinh</li>
 *   <li>atanh</li>
 *   <li>cot</li>
 *   <li>cosh</li>
 *   <li>sinh</li>
 *   <li>tanh</li>
 *   </ul>
 *
 *   <p>
 *   These methods are covered by the following license.
 *   </p>
 *
 * -------------------------------------------------------------------------
 *   $Id: Sfun.java,v 1.1.1.1 1999/03/05 21:43:39 brophy Exp $
 * -------------------------------------------------------------------------
 * Copyright (c) 1997 - 1998 by Visual Numerics, Inc. All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software is freely
 * granted by Visual Numerics, Inc., provided that the copyright notice
 * above and the following warranty disclaimer are preserved in human
 * readable form.
 *
 * Because this software is licensed free of charge, it is provided
 * "AS IS", with NO WARRANTY.  TO THE EXTENT PERMITTED BY LAW, VNI
 * DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO ITS PERFORMANCE, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * VNI WILL NOT BE LIABLE FOR ANY DAMAGES WHATSOEVER ARISING OUT OF THE USE
 * OF OR INABILITY TO USE THIS SOFTWARE, INCLUDING BUT NOT LIMITED TO DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, PUNITIVE, AND EXEMPLARY DAMAGES, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * -------------------------------------------------------------------------
 */
//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        double x = 2.45678;
        int n = 2;
        System.out.println(round(x, n));
    }

    /**   Round double to specified number of decimal places.
     *
     *   @param   x   The double to round.
     *   @param   n   The number of decimal places to round to.
     *
     *   @return      x rounded to n decimal places.
     */

    public static double round(double x, int n) {
        double pow10 = Math.pow(10, n);

        return Math.round(x * pow10) / pow10;
    }
}

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