Example usage for org.apache.commons.math.analysis.solvers NewtonSolver NewtonSolver

Introduction

In this page you can find the example usage for org.apache.commons.math.analysis.solvers NewtonSolver NewtonSolver.

Prototype

@Deprecated
public NewtonSolver() 

Source Link

Document

Construct a solver.

Usage

From source file:cz.cuni.mff.d3s.spl.example.newton.app.Main.java

public static void main(String[] args) {
    try {/*from  ww  w. j  a  v  a 2  s  .co m*/
        System.out.printf("Letting things settle down before actual computation.\n");
        Thread.sleep(1000 * 1);
    } catch (InterruptedException ignored) {
    }

    /* This seed gives reasonable data, keep it at that ;-). */
    Random random = new Random(2);
    double[] coefficients = generateCoefficients(random);

    PolynomialFunction function = new PolynomialFunction(coefficients);
    NewtonSolver solver = new NewtonSolver();

    System.out.printf("Will solve polynomial function of degree %d.\n", function.degree());

    inspectClass(solver);

    try {
        for (int i = 0; i < WARM_UP_LOOPS; i++) {
            double result = solver.solve(10000, function, -1000, 1000);
        }

        long startTimeNanos = System.nanoTime();
        for (int i = 0; i < MEASURED_LOOPS; i++) {
            double result = solver.solve(10000, function, -1000, 1000);
        }
        long endTimeNanos = System.nanoTime();

        long runTimeNanos = endTimeNanos - startTimeNanos;
        long runTimeMillis = runTimeNanos / (1000 * 1000);

        System.out.printf("%d loops of solving took %dns (%dms).\n", MEASURED_LOOPS, runTimeNanos,
                runTimeMillis);
    } catch (MaxIterationsExceededException e) {
        e.printStackTrace();
    } catch (FunctionEvaluationException e) {
        e.printStackTrace();
    }

    inspectClass(solver);
}

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From source file:geogebra.kernel.AlgoRootNewton.java

final double calcRoot(Function fun, double start) {
    double root = Double.NaN;
    if (rootFinderBrent == null)
        rootFinderBrent = new BrentSolver(Kernel.STANDARD_PRECISION);

    // try Brent method with borders close to start value
    try {//from w  w w.j  a v  a  2  s  . c om
        double step = (kernel.getXmax() - kernel.getXmin()) / 10;
        root = rootFinderBrent.solve(MAX_ITERATIONS, new RealRootAdapter(fun), start - step, start + step,
                start);
        if (checkRoot(fun, root)) {
            //System.out.println("1. Brent worked: " + root);
            return root;
        }
    } catch (Exception e) {
        root = Double.NaN;
    }

    // try Brent method on valid interval around start
    double[] borders = getDomain(fun, start);
    try {
        root = rootFinderBrent.solve(MAX_ITERATIONS, new RealRootAdapter(fun), borders[0], borders[1], start);
        if (checkRoot(fun, root)) {
            //System.out.println("2. Brent worked: " + root);
            return root;
        }
    } catch (Exception e) {
        root = Double.NaN;
    }

    // try Newton's method
    RealRootDerivFunction derivFun = fun.getRealRootDerivFunction();
    if (derivFun != null) {
        // check if fun(start) is defined
        double eval = fun.evaluate(start);
        if (Double.isNaN(eval) || Double.isInfinite(eval)) {
            // shift left border slightly right
            borders[0] = 0.9 * borders[0] + 0.1 * borders[1];
            start = (borders[0] + borders[1]) / 2;
        }

        if (rootFinderNewton == null) {
            rootFinderNewton = new NewtonSolver();
        }

        try {
            root = rootFinderNewton.solve(MAX_ITERATIONS, new RealRootDerivAdapter(derivFun), borders[0],
                    borders[1], start);
            if (checkRoot(fun, root)) {
                //System.out.println("Newton worked: " + root);
                return root;
            }
        } catch (Exception e) {
            root = Double.NaN;
        }
    }

    // neither Brent nor Newton worked
    return Double.NaN;
}

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From source file:geogebra.common.kernel.algos.AlgoRootNewton.java

public final double calcRoot(Function fun, double start) {
    double root = Double.NaN;
    if (rootFinderBrent == null)
        rootFinderBrent = new BrentSolver(Kernel.STANDARD_PRECISION);

    // try Brent method with borders close to start value
    try {/*ww  w .  j ava  2s.com*/

        // arbitrary (used to depend on screen width)
        double step = 1;

        root = rootFinderBrent.solve(MAX_ITERATIONS, new RealRootAdapter(fun), start - step, start + step,
                start);
        if (checkRoot(fun, root)) {
            // System.out.println("1. Brent worked: " + root);
            return root;
        }
    } catch (Exception e) {
        root = Double.NaN;
    }

    // try Brent method on valid interval around start
    double[] borders = getDomain(fun, start);
    try {
        root = rootFinderBrent.solve(MAX_ITERATIONS, new RealRootAdapter(fun), borders[0], borders[1], start);
        if (checkRoot(fun, root)) {
            // System.out.println("2. Brent worked: " + root);
            return root;
        }
    } catch (Exception e) {
        root = Double.NaN;
    }

    // try Newton's method
    RealRootDerivFunction derivFun = fun.getRealRootDerivFunction();
    if (derivFun != null) {
        // check if fun(start) is defined
        double eval = fun.evaluate(start);
        if (Double.isNaN(eval) || Double.isInfinite(eval)) {
            // shift left border slightly right
            borders[0] = 0.9 * borders[0] + 0.1 * borders[1];
            start = (borders[0] + borders[1]) / 2;
        }

        if (rootFinderNewton == null) {
            rootFinderNewton = new NewtonSolver();
        }

        try {
            root = rootFinderNewton.solve(MAX_ITERATIONS, new RealRootDerivAdapter(derivFun), borders[0],
                    borders[1], start);
            if (checkRoot(fun, root)) {
                // System.out.println("Newton worked: " + root);
                return root;
            }
        } catch (Exception e) {
            root = Double.NaN;
        }
    }

    // neither Brent nor Newton worked
    return Double.NaN;
}

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