/******************************************************************************
lambd1 = 0.1
N = 10000
def expa(lambd, N):
import random
import math
xi = []
yi = []
sum = 0
sig = 0
for i in range(N):
xi.append(random.random())
yi.append(-1/lambd * math.log(xi[i]))
sum += yi[i]
my = sum / N
for i in range(N):
sig = (yi[i] - my) ** 2
sig = sig / (N - 1)
return yi
*******************************************************************************/
#include <iostream>
#include <cstdlib>
#include <cmath>
#include <ctime>
using namespace std;
double *expa(double *x, double lambda, int n)
{
double *y=new double[n];
int i;
for (i=0; i<n; i++)
{
y[i]=(-1.0/lambda)*log(x[i]);
}
return y;
}
int main()
{
srand(time(0));
int n=1000;
double *y =new double[n],*x = new double[n];
double ymax,ymin,dy,lambda=1.5;
int i,k;
int h[30];
for (i=0; i<n; i++)
{
x[i]=((double)rand() / (double)RAND_MAX);
y[i]=(-1.0/lambda)*log(x[i]);
}
ymax=ymin=y[0];
for (i=1; i<n; i++)
{
if (y[i]>ymax) ymax=y[i];
if (y[i]<ymin) ymin=y[i];
}
dy=(ymax-ymin)/30;
for (i=0; i<30; i++) h[i]=0;
for (i=0; i<n; i++)
{
k=(int)((y[i]-ymin)/dy);
h[k]++;
}
for (i=0; i<30; i++)
cout << ymin+i*dy << " " << h[i] << endl;
delete [] y;
delete [] x;
return 0;
}
