commons-math3 を使って二項比率の信頼区間を求めるデモプログラム。

BinomialProportionDemo.java

import org.apache.commons.math3.stat.interval.*;
 
import java.util.Arrays;
import java.util.List;
 
/**
 * commons-math3 を使って二項比率の信頼区間を求めるデモプログラム。
 */
public class BinomialProportionDemo {
 
    static void demo(int numClicks, int numImpression) {
        List<BinomialConfidenceInterval> methods = Arrays.asList(
                new NormalApproximationInterval(),
                new ClopperPearsonInterval(),
                new WilsonScoreInterval(),
                new AgrestiCoullInterval());
 
        double alpha = 0.05;
 
        System.out.println("---");
 
        for (BinomialConfidenceInterval method : methods) {
            String name = method.getClass().getSimpleName();
 
            try {
                ConfidenceInterval ci = method.createInterval(numImpression, numClicks, 1 - alpha);
                System.out.printf("%s: %s\n", name, ci.toString());
 
            } catch (Exception e) {
                e.printStackTrace();
                System.out.printf("%s: Cannot calculate confidence interval\n", name);
            }
        }
    }
 
    public static void main(String[] args) {
        demo(5, 1000);
        demo(0, 1000);
    }
}