|  | #include <iostream> | 
|  | #include <Eigen/Dense> | 
|  |  | 
|  | int main() { | 
|  | Eigen::Matrix3f A; | 
|  | A << 1, 2, 5, 2, 1, 4, 3, 0, 3; | 
|  | std::cout << "Here is the matrix A:\n" << A << std::endl; | 
|  | Eigen::FullPivLU<Eigen::Matrix3f> lu_decomp(A); | 
|  | std::cout << "The rank of A is " << lu_decomp.rank() << std::endl; | 
|  | std::cout << "Here is a matrix whose columns form a basis of the null-space of A:\n" | 
|  | << lu_decomp.kernel() << std::endl; | 
|  | std::cout << "Here is a matrix whose columns form a basis of the column-space of A:\n" | 
|  | << lu_decomp.image(A) << std::endl;  // yes, have to pass the original A | 
|  | } |