Example usage for org.apache.commons.math.linear RealMatrixImpl RealMatrixImpl

Introduction

In this page you can find the example usage for org.apache.commons.math.linear RealMatrixImpl RealMatrixImpl.

Prototype

public RealMatrixImpl(final double[] v) 

Source Link

Document

Create a new (column) RealMatrix using v as the data for the unique column of the v.length x 1 matrix created.

Usage

From source file:com.discursive.jccook.math.SolveEquations.java

public static void main(String[] args) {

    double[][] coefficients = { { 3.0, 20.0, 89.0 }, { 4.0, 40.0, 298.0 }, { 7.0, 21.0, 0.42 } };

    double[] values = { 1324, 2999, 2039 };

    RealMatrix matrix = new RealMatrixImpl(coefficients);

    double[] answers = matrix.solve(values);

    System.out.println("Answers: " + ArrayUtils.toString(answers));

    double[][] badCoefficients = { { 1, 1, 1 }, { 1, 1, 1 }, { 1, 1, 1 } };

    double[] badValues = { 0, 1, 3 };

    matrix = new RealMatrixImpl(badCoefficients);

    answers = matrix.solve(badValues);//from   w ww .j  a v  a 2 s  . c  om

    System.out.println("Answers: " + ArrayUtils.toString(answers));

}

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From source file:lib.regressions.MultipleRegression.java

/**
 * Perform the regression computations//from   w  w w.  jav  a  2s  .c  o m
 */
private void compute() {
    // Set everything to 0.
    for (int i = 0; i < (myNumVar + 1); i++) {
        myCoef[i] = 0.0;
        myStdErr[i] = 0.0;
        myTStat[i] = 0.0;
    }
    myChiSq = 0.0;
    myRSq = 0.0;
    myAdjustedRSq = 0.0;

    // Set coefficients, t-stat, etc. if there has been enough data added.
    if (myCount >= (myNumVar + 1)) {
        RealMatrix dataMatrix = new RealMatrixImpl(mySums.getSumXX());
        RealMatrix xxMatrix = dataMatrix.getSubMatrix(1, myNumVar + 1, 1, myNumVar + 1);
        RealMatrix xyMatrix = dataMatrix.getSubMatrix(1, myNumVar + 1, 0, 0);

        computeOkX(); // Determine which X components to use.
        int[] listX = getListX();
        int[] listY = { 0 };
        int numX = listX.length;
        RealMatrix xxSubMatrix = xxMatrix.getSubMatrix(listX, listX);
        RealMatrix xySubMatrix = xyMatrix.getSubMatrix(listX, listY);

        double sumY = mySums.getSumXX()[0][1];
        double sumYY = mySums.getSumXX()[0][0];

        if (!xxSubMatrix.isSingular()) {
            RealMatrix xxInverse = xxSubMatrix.inverse();
            RealMatrix coefMatrix = xxInverse.multiply(xySubMatrix);
            double[] coef = coefMatrix.getColumn(0);

            // Compute chi-squared
            myChiSq = sumYY - 2 * coefMatrix.transpose().multiply(xySubMatrix).getEntry(0, 0)
                    + +coefMatrix.transpose().multiply(xxSubMatrix).multiply(coefMatrix).getEntry(0, 0);

            // Compute R^2 and adjusted R^2
            int offset = getUseIntercept() ? 1 : 0;
            myRSq = 1.0 - myChiSq / (sumYY - sumY * sumY / myCount);
            myAdjustedRSq = 1 - ((1 - myRSq) * (myCount - 1) + 1 - offset) / (myCount - numX);

            // Compute standard errors and t-stats
            int j = 0;
            for (int i = 0; i < (myNumVar + 1); i++) {
                if (myOkX[i]) {
                    j++;
                    myCoef[i] = coef[j - 1];
                    myStdErr[i] = Math.sqrt(myChiSq * xxInverse.getEntry(j - 1, j - 1) / (myCount - numX));
                    myTStat[i] = myCoef[i] / myStdErr[i];
                }
            }
        }

    }
    myIsComputed = true;
}

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From source file:com.facebook.infrastructure.service.StorageService.java

/**
 * Get the estimated disk space of the target endpoint in its primary range.
 * //  w  ww.j  av a 2  s. c om
 * @param target
 *          whose primary range we are interested in.
 * @return disk space of the target in the primary range.
 */
private double getDiskSpaceForPrimaryRange(EndPoint target) {
    double primaryDiskSpace = 0d;
    Map<BigInteger, EndPoint> tokenToEndPointMap = tokenMetadata_.cloneTokenEndPointMap();
    Set<BigInteger> tokens = tokenToEndPointMap.keySet();
    Range[] allRanges = getAllRanges(tokens);
    Arrays.sort(allRanges);
    /* Mapping from Range to its ordered position on the ring */
    Map<Range, Integer> rangeIndex = new HashMap<Range, Integer>();
    for (int i = 0; i < allRanges.length; ++i) {
        rangeIndex.put(allRanges[i], i);
    }
    /* Get the coefficients for the equations */
    List<double[]> equations = new ArrayList<double[]>();
    /* Get the endpoint to range map */
    Map<EndPoint, List<Range>> endPointToRangesMap = constructEndPointToRangesMap();
    Set<EndPoint> eps = endPointToRangesMap.keySet();

    for (EndPoint ep : eps) {
        List<Range> ranges = endPointToRangesMap.get(ep);
        double[] equation = new double[allRanges.length];
        for (Range range : ranges) {
            int index = rangeIndex.get(range);
            equation[index] = 1;
        }
        equations.add(equation);
    }
    double[][] coefficients = equations.toArray(new double[0][0]);

    /* Get the constants which are the aggregate disk space for each endpoint */
    double[] constants = new double[allRanges.length];
    int index = 0;
    for (EndPoint ep : eps) {
        /* reset the port back to control port */
        ep.setPort(DatabaseDescriptor.getControlPort());
        String lInfo = null;
        if (ep.equals(StorageService.udpAddr_))
            lInfo = getLoadInfo();
        else
            lInfo = getLoadInfo(ep);
        LoadInfo li = new LoadInfo(lInfo);
        constants[index++] = FileUtils.stringToFileSize(li.diskSpace());
    }

    RealMatrix matrix = new RealMatrixImpl(coefficients);
    double[] solutions = matrix.solve(constants);
    Range primaryRange = getPrimaryRangeForEndPoint(target);
    primaryDiskSpace = solutions[rangeIndex.get(primaryRange)];
    return primaryDiskSpace;
}

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