#include <iostream>
#include <vector>
#include <gsl/gsl_statistics.h>
using namespace std;
int main(void) {
  double data[5] = {17.2, 18.1, 16.5, 18.3, 12.6};
  double mean, variance;
  mean     = gsl_stats_mean(data, 1, 5);
  variance = gsl_stats_variance(data, 1, 5);
  cout<<"     mean = "<<mean<<endl;
  cout<<" variance = "<<variance<<endl;
  // same with a vector container
  vector<double> v;
  v.assign(data,data+5); // reuse data
  mean     = gsl_stats_mean(&v[0], 1, 5);
  variance = gsl_stats_variance(&v[0], 1, 5);
  cout<<"     mean = "<<mean<<endl;
  cout<<" variance = "<<variance<<endl;
  }