d13r8.cpp

Visual C++ 常用数值算法集 源代码

#include "iostream.h"
#include "stdlib.h"
#include "math.h"

void main()
{
    //program d13r8
    //driver for routine chsone
    int i,j,npts = 2000;
    int nbins = 10;
    double bins[11], ebins[11];
    long idum = -15;
    for (j = 1; j<=nbins; j++)
	{
        bins[j] = 0.0;
    }
	double x;
	int ibin;
    for (i = 1; i<=npts; i++)
	{
        x = expdev(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*exp(-3.0*(i-0.5)/nbins);
    }
	double df,chsq,prob;
    chsone(bins, ebins, nbins, -1, df, chsq, prob);
    cout<<endl;
    cout<<"     Expected    Observed"<<endl;
	cout.setf(ios::fixed|ios::right);
	cout.precision(2);
    for (i = 1; i<=nbins; i++)
	{
		cout.width(12);
        cout<<ebins[i];
		cout.width(12);
        cout<<bins[i]<<endl;
    }
    cout<<endl;
	cout.unsetf(ios::fixed);
	cout.setf(ios::scientific);
	cout.precision(5);
    cout<<"Chi-squared: "<<chsq<<endl;
    cout<<"Probability: "<<prob<<endl;
}