Random values and probability distribution, C++ (clang)

Random values and probability distribution

//random number generators and distributions

#include <iostream>
#include <random>

using namespace std;

void UniformIntDist(){
    const int nRolls = 100000; // number of experiments
    const int nStars = 95; // maximum number of stars to distribute
    
    default_random_engine generator;
    uniform_int_distribution<int>distribution(0, 9);    
    
    int p[10] = {};
    
    for(int i=0; i<nRolls; ++i){
        int number = distribution(generator);
        ++p[number];
    }
    
    cout << "uniform_int_distribution<int>distribution(0, 9):\n\n";
    
    for(int i=0; i<10; ++i){
        cout << i << ":" << string(p[i]*nStars/nRolls, '*') << endl;
    }
};
void NormDist(){
    const int nRolls = 100000; // number of experiments
    const int nStars = 100;    // max numebr of stars
    const int classInt = 10;   // class interval
    
    default_random_engine rvGenerator;
    normal_distribution<double>NDist(5.0, 2.0);
    
    int p[10] = {};
    
    for(int i = 0; i < nRolls; i++){
        double number = NDist(rvGenerator);
        if((number >= 0) && (number < 10))
            ++p[int(number)];
     }
    
    cout << "Normal Distribution: NDist(5.0, 2.0)\n\n";
    for(int i=0; i<classInt; i++){
        cout << i << " - " << (i+1) << "\t";
        cout << string(p[i]*nStars/nRolls, '*') << endl;
    }
    
    
    
};
void UniformRealDist(){
    const int nRolls = 100000; // number of experiments
    const int nStars = 95;     // max number of stars
    const int nIntervals = 10; // number of intervals
    
    default_random_engine generator;
    uniform_real_distribution<double>distribution(0.0, 1.0);
    
    int p[nIntervals] = {0};
    
    for(int i=0; i<nRolls; ++i){
    
        double number = distribution(generator);
        ++p[int(number*nIntervals)];
    }
    
    cout << "uniform_real_distribution<double>distribution(0.0, 1.0)" << endl;
        
    cout.setf(ios::fixed);    
    cout.precision(1);
    cout << endl;
    
    for(int i=0; i<nIntervals; ++i){
        cout << float(i)/nIntervals << " - " << float(i+1)/nIntervals << " : ";
        cout << string(p[i]*nStars/nRolls, '*') << endl;
    }

};

void inspect(){
    default_random_engine gen;
    uniform_real_distribution<double>d1(0.0, 100.0);
    uniform_real_distribution<double>d2(d1.param());
    cout << "Two independent random values:\n\n";
    cout << "Random value 1 = " << d1(gen) << endl;
    cout << "Random value 2 = " << d2(gen) << endl;
    
};

int main()
{
   //UniformIntDist();
   //cout << endl;
   //UniformRealDist();
   // cout << endl; 
   //inspect(); 
   // cout << endl;
    NormDist();
    
    
   return 0;
    
}


run \| edit \| history \| help	0