Example usage for org.apache.commons.math3.fraction BigFractionField getInstance

Introduction

In this page you can find the example usage for org.apache.commons.math3.fraction BigFractionField getInstance.

Prototype

public static BigFractionField getInstance() 

Source Link

Document

Get the unique instance.

Usage

From source file:cz.cuni.mff.spl.evaluator.statistics.KolmogorovSmirnovTestFlag.java

/***
 * Creates {@code H} of size {@code m x m} as described in [1] (see above).
 *
 * @param d statistic/*from  ww w. j  a  v  a  2s. c  o  m*/
 * @param n sample size
 * @return H matrix
 * @throws NumberIsTooLargeException if fractional part is greater than 1
 * @throws FractionConversionException if algorithm fails to convert {@code h} to a
 *         {@link org.apache.commons.math3.fraction.BigFraction} in expressing {@code d} as \((k
 *         - h) / m\) for integer {@code k, m} and \(0 <= h < 1\).
 */
private FieldMatrix<BigFraction> createExactH(double d, int n)
        throws NumberIsTooLargeException, FractionConversionException {

    final int k = (int) Math.ceil(n * d);
    final int m = 2 * k - 1;
    final double hDouble = k - n * d;
    if (hDouble >= 1) {
        throw new NumberIsTooLargeException(hDouble, 1.0, false);
    }
    BigFraction h = null;
    try {
        h = new BigFraction(hDouble, 1.0e-20, 10000);
    } catch (final FractionConversionException e1) {
        try {
            h = new BigFraction(hDouble, 1.0e-10, 10000);
        } catch (final FractionConversionException e2) {
            h = new BigFraction(hDouble, 1.0e-5, 10000);
        }
    }
    final BigFraction[][] Hdata = new BigFraction[m][m];

    /*
     * Start by filling everything with either 0 or 1.
     */
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < m; ++j) {
            if (i - j + 1 < 0) {
                Hdata[i][j] = BigFraction.ZERO;
            } else {
                Hdata[i][j] = BigFraction.ONE;
            }
        }
    }

    /*
     * Setting up power-array to avoid calculating the same value twice: hPowers[0] = h^1 ...
     * hPowers[m-1] = h^m
     */
    final BigFraction[] hPowers = new BigFraction[m];
    hPowers[0] = h;
    for (int i = 1; i < m; ++i) {
        hPowers[i] = h.multiply(hPowers[i - 1]);
    }

    /*
     * First column and last row has special values (each other reversed).
     */
    for (int i = 0; i < m; ++i) {
        Hdata[i][0] = Hdata[i][0].subtract(hPowers[i]);
        Hdata[m - 1][i] = Hdata[m - 1][i].subtract(hPowers[m - i - 1]);
    }

    /*
     * [1] states: "For 1/2 < h < 1 the bottom left element of the matrix should be (1 - 2*h^m +
     * (2h - 1)^m )/m!" Since 0 <= h < 1, then if h > 1/2 is sufficient to check:
     */
    if (h.compareTo(BigFraction.ONE_HALF) == 1) {
        Hdata[m - 1][0] = Hdata[m - 1][0].add(h.multiply(2).subtract(1).pow(m));
    }

    /*
     * Aside from the first column and last row, the (i, j)-th element is 1/(i - j + 1)! if i -
     * j + 1 >= 0, else 0. 1's and 0's are already put, so only division with (i - j + 1)! is
     * needed in the elements that have 1's. There is no need to calculate (i - j + 1)! and then
     * divide - small steps avoid overflows. Note that i - j + 1 > 0 <=> i + 1 > j instead of
     * j'ing all the way to m. Also note that it is started at g = 2 because dividing by 1 isn't
     * really necessary.
     */
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < i + 1; ++j) {
            if (i - j + 1 > 0) {
                for (int g = 2; g <= i - j + 1; ++g) {
                    Hdata[i][j] = Hdata[i][j].divide(g);
                }
            }
        }
    }
    return new Array2DRowFieldMatrix<BigFraction>(BigFractionField.getInstance(), Hdata);
}

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From source file:org.matheclipse.commons.parser.client.eval.bigfraction.BigFractionEvaluator.java

public BigFractionEvaluator(ASTNode node, boolean relaxedSyntax) {
    super(relaxedSyntax);
    fASTFactory = new ASTNodeFactory(relaxedSyntax);
    fVariableMap = new HashMap<String, FieldElementVariable<BigFraction>>();
    fBooleanVariables = new HashMap<String, BooleanVariable>();
    fNode = node;//from   ww w.ja v  a 2s  .co m
    fDfpField = BigFractionField.getInstance();
    fZERO = new BigFractionNode(fDfpField.getZero());
    init();
    if (fRelaxedSyntax) {
        if (SYMBOL_MAP.get("pi") == null) {
            // init tables for relaxed mode
            for (String key : SYMBOL_MAP.keySet()) {
                SYMBOL_MAP.put(key.toLowerCase(), SYMBOL_MAP.get(key));
            }
            for (String key : SYMBOL_BOOLEAN_MAP.keySet()) {
                SYMBOL_BOOLEAN_MAP.put(key.toLowerCase(), SYMBOL_BOOLEAN_MAP.get(key));
            }
            for (String key : FUNCTION_MAP.keySet()) {
                FUNCTION_MAP.put(key.toLowerCase(), FUNCTION_MAP.get(key));
            }
            for (String key : FUNCTION_BOOLEAN_MAP.keySet()) {
                FUNCTION_BOOLEAN_MAP.put(key.toLowerCase(), FUNCTION_BOOLEAN_MAP.get(key));
            }
        }
    }
}

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