TutorialLinAlgRankRevealing.cpp revision c981c48f5bc9aefeffc0bcb0cc3934c2fae179dd 
1#include <iostream>
2#include <Eigen/Dense>
3
4using namespace std;
5using namespace Eigen;
6
7int main()
8{
9   Matrix3f A;
10   A << 1, 2, 5,
11        2, 1, 4,
12        3, 0, 3;
13   cout << "Here is the matrix A:\n" << A << endl;
14   FullPivLU<Matrix3f> lu_decomp(A);
15   cout << "The rank of A is " << lu_decomp.rank() << endl;
16   cout << "Here is a matrix whose columns form a basis of the null-space of A:\n"
17        << lu_decomp.kernel() << endl;
18   cout << "Here is a matrix whose columns form a basis of the column-space of A:\n"
19        << lu_decomp.image(A) << endl; // yes, have to pass the original A
20}
21