Java BigDecimal median(final BigDecimal[] bigDecimalNumbers)

Description

median

License

Open Source License

Declaration

private static BigDecimal median(final BigDecimal[] bigDecimalNumbers)

Method Source Code

//package com.java2s;
/*/*from   ww  w .  j ava 2s.  c o m*/
 Copyright 2008-2010 Gephi
 Authors : Eduardo Ramos <eduramiba@gmail.com>
 Website : http://www.gephi.org

 This file is part of Gephi.

 DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 Copyright 2011 Gephi Consortium. All rights reserved.

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 "License"). You may not use this file except in compliance with the
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 or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
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 */

import java.math.BigDecimal;

import java.util.Arrays;
import java.util.Collection;

public class Main {
    /**
     * <p>Calculate median of various numbers as a BigDecimal.</p>
     * <p>The elements can't be null.</p>
     * <p>The elements don't need to be sorted.</p>
     * @param numbers Not null numbers to calculate median
     * @return Median as a BigDecimal
     */
    public static BigDecimal median(Number[] numbers) {
        if (numbers == null || numbers.length == 0) {
            return null;
        }

        BigDecimal[] bigDecimalNumbers = numbersArrayToSortedBigDecimalArray(numbers);
        return median(bigDecimalNumbers);
    }

    /**
     * <p>Calculate median of various numbers as a BigDecimal.</p>
     * <p>The elements can't be null.</p>
     * <p>The elements don't need to be sorted.</p>
     * @param numbers Not null numbers to calculate median
     * @return Median as a BigDecimal
     */
    public static BigDecimal median(Collection<Number> numbers) {
        return median(numbers.toArray(new Number[0]));
    }

    private static BigDecimal median(final BigDecimal[] bigDecimalNumbers) {
        return median(bigDecimalNumbers, 0, bigDecimalNumbers.length);
    }

    private static BigDecimal median(final BigDecimal[] bigDecimalNumbers,
            final int start, final int end) {
        final int size = end - start;

        if (size % 2 == 1) {
            return bigDecimalNumbers[start + (size + 1) / 2 - 1];
        } else {
            BigDecimal result = bigDecimalNumbers[start + (size) / 2 - 1];
            result = result.add(bigDecimalNumbers[start + (size) / 2]);
            return result.divide(BigDecimal.valueOf(2));
        }
    }

    /**
     * <p>Takes an array of numbers of any type combination and returns
     * an array with their BigDecimal equivalent numbers.</p>
     * @return BigDecimal array
     */
    public static BigDecimal[] numbersArrayToSortedBigDecimalArray(
            Number[] numbers) {
        if (numbers == null) {
            return null;
        }
        BigDecimal[] result = new BigDecimal[numbers.length];
        Number number;
        for (int i = 0; i < result.length; i++) {
            number = numbers[i];
            if (number != null) {
                result[i] = new BigDecimal(number.toString());
            }
        }
        Arrays.sort(result);
        return result;
    }
}

Java BigDecimal median(final BigDecimal[] bigDecimalNumbers)

Description

License

Declaration

Method Source Code

Related