Java Number Round roundToSignificantDigits(double num, int n)

Description

round To Significant Digits

License

Apache License

Declaration

public static double roundToSignificantDigits(double num, int n) 

Method Source Code

//package com.java2s;
/*/* www  . j  av a  2s. com*/
 *    Copyright 2010-2012 University of Toronto
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

public class Main {
    public static double roundToSignificantDigits(double num, int n) {
        if (num == 0) {
            return 0;
        } else if (n == 0) {
            return Math.round(num);
        }

        String s = num + "";
        int index = s.indexOf(".");
        while (n >= s.length() - index) {
            s = s + "0";
        }
        return Double.parseDouble(s.substring(0, index + n + 1));
    }
}

Related

1. roundToPowerOf2(int value)
2. roundToPrecision(double number, int precision)
3. roundToPrecision(float value, int numDecimalPlaces)
4. roundToQuarterMs(float f)
5. roundToShort(final double d)
6. roundToSignificantDigits(double value, int n)
7. roundToSignificantDigits(double x, double y, int nSignif)
8. roundToSignificantFigures(double num, int n)
9. RoundToStr(double value, int dec)