eigen vector.at() code example
Example 1: transpose matrix eigen c++
MatrixXcf a = MatrixXcf::Random(2,2);
cout << "Here is the matrix a\n" << a << endl;
cout << "Here is the matrix a^T\n" << a.transpose() << endl;
Example 2: matrix multiplication c++ eigen
Matrix2d mat;
mat << 1, 2,
3, 4;
std::cout << "Here is mat*mat:\n" << mat*mat << std::endl;