Example usage for org.apache.commons.math.analysis.solvers BrentSolver DEFAULT_ABSOLUTE_ACCURACY

Introduction

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

Prototype

double DEFAULT_ABSOLUTE_ACCURACY

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Document

Default absolute accuracy

Usage

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

@Test
public void testOrthoDist() {

    AngleDerivativeFunction angleDerivative = new AngleDerivativeFunction();
    BrentSolver solver = new BrentSolver(BrentSolver.DEFAULT_ABSOLUTE_ACCURACY);
    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);/*from w  ww. j  a  va  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(BrentSolver.DEFAULT_MAXIMUM_ITERATIONS, 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 (MaxIterationsExceededException e) {
        // TODO
        System.err.println(e);
    } catch (FunctionEvaluationException e) {
        // TODO
        System.err.println(e);
    }

}

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