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

Introduction

In this page you can find the example usage for org.apache.commons.math3.analysis.solvers BrentSolver 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:jat.core.cm.CRTBP.java

public void findZeroVelocity() {
    JacobiFixedx JF = new JacobiFixedx();
    BisectionSolver bis = new BisectionSolver();
    BrentSolver brs = new BrentSolver();
    JF.setC(C);//from w  w  w  . j av  a2  s  .c  om
    double x = -1.;
    double lasty = 0;
    while ((x += .01) < 1.3) {
        JF.setx(x);

        double y = 0;
        boolean success = false;
        try {
            success = true;
            y = brs.solve(100, JF, lasty - .4, lasty + .4);
            // y = brs.solve(100, JF, -.1, .8);
            // double y = bis.solve(100, JF, 0, 2);
        } catch (NoBracketingException e) {
            success = false;
            // System.out.println("exception at x y " + x + " " + y);

        } finally {

            if (success) {
                // System.out.println("x y " + x + " " + y);

                xzv.add(x);
                yzv.add(y);
                lasty = y;
                //System.out.println("last y " + lasty);
            }

        }
    }
}

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From source file:uk.ac.diamond.scisoft.analysis.roi.fitting.EllipseFitterTest.java

@Test
public void testOrthoDist() {

    AngleDerivativeFunction angleDerivative = new AngleDerivativeFunction();
    BrentSolver solver = new BrentSolver();
    double a = 10.2;
    double b = 3.1;
    final double twopi = 2 * Math.PI;
    double alpha = twopi * 10. / 360; // 0 to 2 pi
    angleDerivative.setRadii(a, b);/*w ww  .  j a v  a 2  s .co m*/
    angleDerivative.setAngle(alpha);

    //      final double ca = 0;
    //      final double cb = b-0.5;
    final double Xc = -5.; // Math.cos(alpha)*ca + Math.sin(alpha)*cb;
    final double Yc = 5.5; //Math.sin(alpha)*ca + Math.cos(alpha)*cb;

    angleDerivative.setCoordinate(Xc, Yc);
    try {
        // find quadrant to use
        double p = Math.atan2(Yc, Xc);
        if (p < 0)
            p += twopi;
        p -= alpha;
        final double end;
        final double halfpi = 0.5 * Math.PI;
        p /= halfpi;
        end = Math.ceil(p) * halfpi;
        final double angle = solver.solve(100, angleDerivative, end - halfpi, end);
        //         final double cos = Math.cos(angle);
        //         final double sin = Math.sin(angle);

        Assert.assertEquals("Angle found is not close enough", 1.930, angle, 0.001);
        //         double dx = a*cos + Xc;
        //         double dy = b*sin + Yc;
        //
        //         System.out.println("Bracket angle = " + Math.ceil(p));
        //         System.out.println("Delta angle = " + 180.*angle/Math.PI);
        //         System.out.println(dx + ", " + dy);
    } catch (TooManyEvaluationsException e) {
        // TODO
        System.err.println(e);
    } catch (MathIllegalArgumentException e) {
        // TODO
        System.err.println(e);
    }

}

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