matrix multiplication c 2b 2b eigen

1MatrixXcf a = MatrixXcf::Random(2,2);
2cout << "Here is the matrix a\n" << a << endl;
3 
4cout << "Here is the matrix a^T\n" << a.transpose() << endl;

1  Matrix2d mat;
2  mat << 1, 2,
3         3, 4;
4  std::cout << "Here is mat*mat:\n" << mat*mat << std::endl;