private void findBracket() {
if (myWFunction.fx(1.0) > 0.0) {
myAlphaPos = 1.0;
double alpha = 1.0;
do {
alpha = alpha * 2.0;
} while (myWFunction.fx(alpha) >= 0.0); // when f(a) < 0, then it drops out of the while loop
myAlphaNeg = alpha;
} else {
myAlphaNeg = 1.0;
double alpha = 1.0;
do {
alpha = alpha / 2.0;
} while (myWFunction.fx(alpha) <= 0.0); // when f(a) > 0, then it drops out of the while loop
myAlphaPos = alpha;
}
}
private void matchWeibull(double mean, Weibull w) {
myC2vCDF.setRange(0.0, myMaxC2v);
boolean flag = true;
do {
double c2v = myC2vCDF.getValue();
myWFunction.setC2v(c2v);
findBracket();
myZeroFinder.setInterval(myWFunction, myAlphaNeg, myAlphaPos);
myZeroFinder.setInitialPoint((myAlphaNeg + myAlphaPos) / 2.0);
myZeroFinder.evaluate();
double shape = myZeroFinder.getResult();
double scale = mean / Gamma.gammaFunction(1.0 + 1.0 / shape);
w.setScale(scale);
w.setShape(shape);
if (myZeroFinder.hasConverged()) flag = true;
else flag = false;
} while (flag == false);
}