#include#include using namespace Eigen; using namespace std; int main() { MatrixXd M(3,3); M << 1, 2, 3, 4, 5, 6, 7, 8, 9; VectorXd v = M.col(1); cout << "Matrix M:\n" << M << endl; cout << "Second column of M:\n" << v << endl; return 0; }
#includeIn this example, a 3x3 matrix `M` is initialized and the first column is set to the sum of the second and third columns using the col method. The resulting `M` matrix is printed to the console. Both examples use the Eigen library.#include using namespace Eigen; using namespace std; int main() { MatrixXd M(3,3); M << 1, 2, 3, 4, 5, 6, 7, 8, 9; M.col(0) = M.col(1) + M.col(2); cout << "Matrix M after column operation:\n" << M << endl; return 0; }