#include #include using Eigen::Matrix3d; using Eigen::Vector3d; int main(int, char *[]) { Matrix3d m; for (int row = 0; row < 3; ++row) for (int column = 0; column < 3; ++column) m(row, column) = row + 0.01 * column; Vector3d v = Vector3d::Ones(); std::cout << m * v << std::endl; }