d13r9.txt

JAVA数值计算算法集随书源码

import java.text.*;
public class d13r9
{
	public static void main (String[] args)
	{
        //program d13r9
		//driver for routine chsone
        int i, j, npts = 2000;
		int nbins = 10;
        double bins[] = new double[11];
        double ebins[] = new double[11];
		int idum = -15;
        d13r9F g = new d13r9F();
        DecimalFormat form = new DecimalFormat("0.00");
		for (j = 1; j<=nbins; j++)
		{
            bins[j] = 0.0;
		}
		double x;
		int ibin;
        for (i = 1; i <= npts; i++)
		{
            x = g.expdev(idum);
            idum = g.expedv_idum;
            ibin = (int)(x * nbins / 3.0) + 1;
            if (ibin <= nbins)
			{
				bins[ibin] = bins[ibin] + 1.0;
			}
		}
        for (i = 1; i <= nbins; i++)
		{
            ebins[i] = 3.0 * npts / nbins * Math.exp(-3.0 * (i - 0.5) / nbins);
		}
        double df, chsq, prob;
        df = 0.0; chsq = 0.0; prob = 0.0;
		g.chsone(bins, ebins, nbins, -1, df, chsq, prob);
        df = g.chsone_df;
        chsq = g.chsone_chsq;
        prob = g.chsone_prob;  
		System.out.println();
        System.out.println("    Expected    Observed");
        for (i = 1; i <= nbins; i++)
		{
            System.out.print("    "+form.format(ebins[i]) + "    ");
            System.out.println(form.format(bins[i]) + "     ");
		}
		System.out.println();
        form = new DecimalFormat("0.00000");
        System.out.println("Chi-squared: "+form.format(chsq));
        System.out.println("Probability: "+form.format(prob)); 
	}
}