#include <iostream>
#include "armadillo"
using namespace arma;
using namespace std;

int main(int argc, char** argv)
  {
  // directly specify the matrix size (elements are uninitialised)
  mat A(2,3);
  // .n_rows = number of rows    (read only)
  // .n_cols = number of columns (read only)
  cout << "A.n_rows = " << A.n_rows << endl;
  cout << "A.n_cols = " << A.n_cols << endl;
  // directly access an element (indexing starts at 0)
  A(1,2) = 456.0;
  A.print("A:");
  // scalars are treated as a 1x1 matrix,
  // hence the code below will set A to have a size of 1x1
  A = 5.0;
  A.print("A:");
  // if you want a matrix with all elements set to a particular value
  // the .fill() member function can be used
  A.set_size(3,3);
  A.fill(5.0);  A.print("A:");