1#include <unsupported/Eigen/MatrixFunctions>
2#include <iostream>
3
4using namespace Eigen;
5
6std::complex<double> expfn(std::complex<double> x, int)
7{
8  return std::exp(x);
9}
10
11int main()
12{
13  const double pi = std::acos(-1.0);
14
15  MatrixXd A(3,3);
16  A << 0,    -pi/4, 0,
17       pi/4, 0,     0,
18       0,    0,     0;
19
20  std::cout << "The matrix A is:\n" << A << "\n\n";
21  std::cout << "The matrix exponential of A is:\n"
22            << A.matrixFunction(expfn) << "\n\n";
23}
24