Example usage for org.apache.commons.math3.analysis.solvers LaguerreSolver solve

Introduction

In this page you can find the example usage for org.apache.commons.math3.analysis.solvers LaguerreSolver solve.

Prototype

double solve(int maxEval, FUNC f, double min, double max);

Source Link

Document

Solve for a zero root in the given interval.

Usage

From source file:curveavg.SolverTest.java

@Test
public void testQuinticZero_NewtonRaphsonFailureCase() {

    // Solve using NewtonRaphson and count the number of results
    float c[] = { -38.764412f, 76.10117f, -56.993206f, 28.603401f, -10.2824955f, 1.0f };
    MedialAxisTransform.SolverResult res = MedialAxisTransform.solveQuinticNewtonRaphson(c[0], c[1], c[2], c[3],
            c[4], c[5]);//from w  w w  .  j a  v a 2  s  .c o  m
    int rootsNR = 0;
    for (int i = 0; i < res.im.length; i++) {
        if (Math.abs(res.im[i]) < 1e-3)
            rootsNR++;
    }
    System.out.println("# NR roots: " + rootsNR);

    // Solve using NewtonRaphson and count the number of results
    MedialAxisTransform.SolverResult res2 = MedialAxisTransform.solveQuinticLaguerre(c[0], c[1], c[2], c[3],
            c[4], c[5]);
    int rootsL = 0;
    for (int i = 0; i < res.im.length; i++) {
        if (Math.abs(res2.im[i]) < 1e-3)
            rootsL++;
    }
    System.out.println("# L roots: " + rootsL);

    // Solve using Laguerre
    double dt = 0.01;
    double coefficients[] = new double[6];
    for (int i = 0; i < 6; i++)
        coefficients[i] = c[5 - i];
    PolynomialFunction f = new PolynomialFunction(coefficients);
    LaguerreSolver solver = new LaguerreSolver();
    for (double t = 0; t <= (1.0 - dt); t += dt) {

        // Check if there is a sign-crossing between the two times
        double t2 = t + dt;
        double f1 = f.value(t);
        double f2 = f.value(t2);
        if (Math.signum(f1) == Math.signum(f2))
            continue;

        // Compute using Laguerre
        double result = solver.solve(100, f, t, t2);
        System.out.println("Result: " + result);
    }

}

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From source file:curveavg.MedialAxisTransform.java

/**
 * Uses the Laguerre algorithm iteratively to span the range [0,1] and find
 * all the real roots.//from  w  w  w .j av  a  2s.c o  m
 */
public static SolverResult solveQuinticLaguerre(float a, float b, float c, float d, float e, float f) {

    // Initialize the result
    //            System.out.println("quintic params: " + a + ", "+ b + ", "+ c + ", "+ d + ", "+ e + ", "+ f);
    SolverResult res = new SolverResult();
    res.re = new float[6];
    res.im = new float[6];
    for (int i = 0; i < 6; i++) {
        res.im[i] = 1.0f;
    }

    // Create the quintic function and the solver
    double coefficients[] = { f, e, d, c, b, a };
    PolynomialFunction qf = new PolynomialFunction(coefficients);
    LaguerreSolver solver = new LaguerreSolver();

    // Iteratively call the NewtonRaphson solution until no solution 
    // exists
    double minBound = 0.0;
    double sol;
    int root_idx = 0;
    final double dt = 0.01;
    for (double t = -dt; t < 1.0; t += dt) {

        // Check if there is a sign-crossing between the two times
        double t2 = t + dt;
        double f1 = qf.value(t);
        double f2 = qf.value(t2);
        if (Math.signum(f1) == Math.signum(f2)) {
            continue;
        }

        // Attempt to get the solution
        try {
            sol = solver.solve(100, qf, t, t2);
        } catch (TooManyEvaluationsException | NumberIsTooLargeException exc) {
            break;
        }

        // Save the root and update the minimum bound
        res.re[root_idx] = (float) sol;
        res.im[root_idx] = 0.0f;
        minBound = sol + 1e-3;
        root_idx++;
    }

    //            System.out.println("#quintic roots: " + root_idx);
    return res;
}

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