Example usage for org.apache.commons.math3.linear RRQRDecomposition RRQRDecomposition

Introduction

In this page you can find the example usage for org.apache.commons.math3.linear RRQRDecomposition RRQRDecomposition.

Prototype

public RRQRDecomposition(RealMatrix matrix) 

Source Link

Document

Calculates the QR-decomposition of the given matrix.

Usage

From source file:edu.cmu.tetrad.util.ApacheTetradMatrix.java

public int rank() {
    return new RRQRDecomposition(apacheData).getRank(0.1);
}

---

From source file:org.jgrasstools.hortonmachine.modules.geomorphology.curvatures.OmsCurvaturesBivariate.java

/**
 * Calculates the parameters of a bivariate quadratic equation.
 * /*from  www  .  j  av a 2 s .  c  o  m*/
 * @param elevationValues the window of points to use.
 * @return the parameters of the bivariate quadratic equation as [a, b, c, d, e, f]
 */
private static double[] calculateParameters(final double[][] elevationValues) {
    int rows = elevationValues.length;
    int cols = elevationValues[0].length;
    int pointsNum = rows * cols;

    final double[][] xyMatrix = new double[pointsNum][6];
    final double[] valueArray = new double[pointsNum];

    // TODO check on resolution
    int index = 0;
    for (int y = 0; y < rows; y++) {
        for (int x = 0; x < cols; x++) {
            xyMatrix[index][0] = x * x; // x^2
            xyMatrix[index][1] = y * y; // y^2
            xyMatrix[index][2] = x * y; // xy
            xyMatrix[index][3] = x; // x
            xyMatrix[index][4] = y; // y
            xyMatrix[index][5] = 1;
            valueArray[index] = elevationValues[y][x];
            index++;
        }
    }

    RealMatrix A = MatrixUtils.createRealMatrix(xyMatrix);
    RealVector z = MatrixUtils.createRealVector(valueArray);

    DecompositionSolver solver = new RRQRDecomposition(A).getSolver();
    RealVector solution = solver.solve(z);

    // start values for a, b, c, d, e, f, all set to 0.0
    final double[] parameters = solution.toArray();
    return parameters;
}

---

From source file:org.jgrasstools.lesto.modules.raster.Las2BivariateRasterMosaic.java

private double[] calculateParameters(final List<LasRecord> pointsInGeometry) {
    int pointsNum = pointsInGeometry.size();

    final double[][] xyMatrix = new double[pointsNum][6];
    final double[] valueArray = new double[pointsNum];
    for (int i = 0; i < pointsNum; i++) {
        LasRecord dot = pointsInGeometry.get(i);
        xyMatrix[i][0] = dot.x * dot.x; // x^2
        xyMatrix[i][1] = dot.y * dot.y; // y^2
        xyMatrix[i][2] = dot.x * dot.y; // xy
        xyMatrix[i][3] = dot.x; // x
        xyMatrix[i][4] = dot.y; // y
        xyMatrix[i][5] = 1;//from  w  w  w.ja v  a2 s .c o  m
        if (doIntensity) {
            valueArray[i] = dot.intensity;
        } else {
            valueArray[i] = dot.z;
        }
    }

    RealMatrix A = MatrixUtils.createRealMatrix(xyMatrix);
    RealVector z = MatrixUtils.createRealVector(valueArray);

    DecompositionSolver solver = new RRQRDecomposition(A).getSolver();
    RealVector solution = solver.solve(z);

    // start values for a, b, c, d, e, f, all set to 0.0
    final double[] parameters = solution.toArray();
    return parameters;
}

---