Example usage for org.apache.commons.math.linear RealVector toArray

Introduction

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

Prototype

double[] toArray();

Source Link

Document

Convert the vector to a double array.

Usage

From source file:com.zinnia.nectar.util.math.MatrixSolver.java

public static double[] solveMatrix(double[][] coefficientMatrix, double[] rhsVector) {
    RealVector x = null;
    try {//from   w  w  w  . j a v  a 2s . c o  m
        RealMatrix a = new Array2DRowRealMatrix(coefficientMatrix);
        RealVector b = new ArrayRealVector(rhsVector);
        DecompositionSolver solver = new LUDecompositionImpl(a).getSolver();
        x = solver.solve(b);
    } catch (Exception e) {
        e.printStackTrace();
    }

    double[] result;
    result = x.toArray();

    return result;
}

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From source file:juicebox.data.MatrixZoomData.java

/**
 * Computes eigenvector from Pearson's.//from   www . ja v  a  2s . co m
 *
 * @param df    Expected values, needed to get Pearson's
 * @param which Which eigenvector; 0 is principal.
 * @return Eigenvector
 */
public double[] computeEigenvector(ExpectedValueFunction df, int which) {
    BasicMatrix pearsons = getPearsons(df);
    if (pearsons == null) {
        return null;
    }

    int dim = pearsons.getRowDimension();
    double[][] data = new double[dim][dim];
    BitSet bitSet = new BitSet(dim);
    for (int i = 0; i < dim; i++) {
        for (int j = 0; j < dim; j++) {
            float tmp = pearsons.getEntry(i, j);
            data[i][j] = tmp;
            if (data[i][j] != 0 && !Float.isNaN(tmp)) {
                bitSet.set(i);
            }
        }
    }

    int[] nonCentromereColumns = new int[bitSet.cardinality()];
    int count = 0;
    for (int i = 0; i < dim; i++) {
        if (bitSet.get(i))
            nonCentromereColumns[count++] = i;
    }

    RealMatrix subMatrix = new Array2DRowRealMatrix(data).getSubMatrix(nonCentromereColumns,
            nonCentromereColumns);
    RealVector rv = (new EigenDecompositionImpl(subMatrix, 0)).getEigenvector(which);

    double[] ev = rv.toArray();

    int size = pearsons.getColumnDimension();
    double[] eigenvector = new double[size];
    int num = 0;
    for (int i = 0; i < size; i++) {
        if (num < nonCentromereColumns.length && i == nonCentromereColumns[num]) {
            eigenvector[i] = ev[num];
            num++;
        } else {
            eigenvector[i] = Double.NaN;
        }
    }
    return eigenvector;

}

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