#include <unsupported/Eigen/MatrixFunctions>
#include <iostream>
using namespace Eigen;
int main()
{
const double pi = std::acos(-1.0);
MatrixXd A(2,2);
A << cos(pi/3), -sin(pi/3),
sin(pi/3), cos(pi/3);
std::cout << "The matrix A is:\n" << A << "\n\n";
std::cout << "The matrix square root of A is:\n" << A.sqrt() << "\n\n";
std::cout << "The square of the last matrix is:\n" << A.sqrt() * A.sqrt() << "\n";
}