C++ Program For Chi-Square Test For Uniformity

The random numbers are very important for any analysis in the simulation study. One such test for the testing the uniformity is the Chi-Square Test for Uniformity.

Also Read: C++ Program for Kolmogorov-Smirnov(KS) Test for Uniformity

Algorithm:

Step 1: Define the Hypothesis:
Ho: The numbers are uniformly distributed
H1: The numbers are not uniformly distributed.

Step 2: Use the Test Stat As Below:
Xo^2=∑((Oi-Ei)^2/Ei)

Step3: Determine the Critical Value for the given level of significance(α) and n-1.

Step 4: Compare the Obtained Chi-Square value and tabulated Chi-Square value using α and n-1.
if (calculated Chi-Square value > tabulated chi-square value),then
reject Ho.
else
accept Ho.

Source Code in C++:

#include<iostream>
#include<conio.h>
#include<iomanip>
using namespace std;

class chisquare
{
	private:
		int n, observed[20],i,N,Expected;
		float Calculation[20],final,critical;
		
	public:
		chisquare() //constructor to initialize values
		{
			N=0;
			final=0.00;
		}
		
		void getdata() //getting observed frequency
		{
			cout<<"How many numbers:?"<<endl;
			cin>>n;
			cout<<"Enter the observed frequency:"<<endl;
			for(i=0;i<n;i++)
			{
				cout<<"Enter "<<i+1<<"th number: "<<endl;
				cin>>observed[i];
			}
		}
		
		
		void calculation() //calculation of N(total frequency), Calculation(((Oi-Ei)^2/Ei)),final(?)
		{
			for(i=0;i<n;i++)
			{
				N=N+observed[i];
			}
			Expected=N/n;
			for(i=0;i<n;i++)
			{
				Calculation[i]=(float)((observed[i]-Expected)*(observed[i]-Expected))/Expected;
				final=final+Calculation[i];
			}
		}
		
		void display() //display in tabulated format
		{
			cout<<setw(5)<<"S.No";
			cout<<setw(5)<<"Oi";
			cout<<setw(5)<<"Ei";
			cout<<setw(22)<<"((Oi-Ei)*(Oi-Ei))/Ei"<<endl;
			for(i=0;i<n;i++)
			{
				cout<<setw(5)<<i+1;
				cout<<setw(5)<<observed[i];
				cout<<setw(5)<<Expected;
				cout<<setw(10)<<setprecision(2)<<Calculation[i]<<endl;
			}
			cout<<"-------------------------------------------------------"<<endl;
			cout<<setw(10)<<N;
			cout<<setw(15)<<final;
			cout<<endl;
		}
		
		
		void conclusion() //compare tabulated and calculated value and conclude if Ho is accepted.
		{
			cout<<endl;
			cout<<"Enter the critical value:"<<endl;
			cin>>critical;
			if(final<critical)
			{
				cout<<"The test is accepted"<<endl;
			}
			else
			{
				cout<<"The test is rejected"<<endl;
			}
		}
		
};
int main()
{
	chisquare c;
	c.getdata();
	c.calculation();
	c.display();
	c.conclusion();
	getch();
	return(0);
}

Output:

Comment down below if you are confused in any steps.