check.c

利用线形组合法

#include <stdio.h>
#include <math.h>

#define a 314159269
#define c 453806246
#define m 2147483648
#define N 1000

int seed1=1;
	
float myrand(void)
{
    int i;

	for (i=0;i<10;i++) 
	seed1 = (a * seed1 + c) % m;
	
	return (float) seed1/m;

}



/*main function to check whether the genrated numbers is satiesfied*/
main()
{
	int j,n[4]={0,0,0,0},K; 
	float sum,u,s_sqr,v1,X2,p, rand[N];
	char flag;


	printf ("*********************************************************************\n");
	printf ("* This program will check whether the random generator is qualified *\n");
	printf ("*********************************************************************\n\n");

	printf ("The first 1000 random numbers: \n\n");

	/*store the random nums in an array and print these nums out*/
	sum =0;
	for (j=0;j<N;j++) {
		rand[j] = myrand();
		sum+=rand[j];

		printf("%.3f ", rand[j]);
		if ((j+1)%10 == 0) printf("\n");
	}
	
	/*mean value check*/
	u= sum / N;
	v1= pow(12*N,0.5)*(u-0.5);

	printf (  "\nu    = %.3f",u);
	if ( (abs(v1) < 1.96) ) printf ("\nMean Value ACCEPTED!\n");
	else printf ("\nMean Value REJECTED!\n");
	
	/*sigma_sqr check*/
	sum=0;

	for (j=0;j<N;j++){
		sum += (rand[j]-u)*(rand[j]-u);
	}

	s_sqr= sum / (N-1); 
	
	printf (  "\nS2    = %.3f",s_sqr);
	if ( (abs(s_sqr) < 1.96 )) printf ("\nSigma_sqr ACCEPTED!\n");
	else printf ("\nSigma REJECTED!\n");

	/* X2 check */
	sum =0;
	for (j=0;j<N;j++) {/*count the nums in each domain*/

		if (rand[j]<=0.25) n[0]++;
		else if (rand[j]<=0.5) n[1]++;
		else if (rand[j]<=0.75) n[2]++;
		else if (rand[j]<=1) n[3]++;
		else printf("ERROR!\n");
	}


	for (j=0;j<4;j++) sum += (n[j] - N/4)*(n[j] - N/4);	
	X2 = sum * 4 /N;

	if (X2 < 7.81473) printf ("\nX2 ACCEPTED!\n");
	else printf ("\nX2 REJECTED!\n");

	/* independence check */
	
	flag = 0;
	for (K=1;K<51;K++){/*for every shift the p should be accepted*/
		sum = 0;

		for (j=0;j<N-K;j++) sum += rand[j]*rand[j+K];
		p = (sum/(N-K)-u*u) * pow(N-K,0.5) / s_sqr;

		
		if(abs(p)>1.96) {
			printf("\nWhen K = %d, p = %.3f OVERLOAD!",K,p);
			flag =1;
		}
			
	}
	if (flag == 0) printf ("\nIndependence ACCEPTED!\n");
	else printf("\nIndependence REJECTED!\n");
 

	while(1);

}