// maximum from each row (traverse along columns)
  cout << "max(B,1) =" << endl;
  cout << max(B,1) << endl;
  // maximum value in B
  cout << "max(max(B)) = " << max(max(B)) << endl;
  // sum of each column (traverse along rows)
  cout << "sum(B) =" << endl;
  cout << sum(B) << endl;
  // sum of each row (traverse along columns)
  cout << "sum(B,1) =" << endl;
  cout << sum(B,1) << endl;
  // sum of all elements
  cout << "sum(sum(B)) = " << sum(sum(B)) << endl;
  cout << "accu(B)     = " << accu(B) << endl;
  // trace = sum along diagonal
  cout << "trace(B)    = " << trace(B) << endl;
  // random matrix -- values are uniformly distributed in the [0,1] interval
  mat E = randu<mat>(4,4);
  E.print("E:");