1 #include <iostream> 2 #include <Eigen/SVD> 3 using namespace Eigen; 4 using namespace std; 5 6 float inv_cond(const Ref<const MatrixXf>& a) 7 { 8 const VectorXf sing_vals = a.jacobiSvd().singularValues(); 9 return sing_vals(sing_vals.size()-1) / sing_vals(0); 10 } 11 12 int main() 13 { 14 Matrix4f m = Matrix4f::Random(); 15 cout << "matrix m:" << endl << m << endl << endl; 16 cout << "inv_cond(m): " << inv_cond(m) << endl; 17 cout << "inv_cond(m(1:3,1:3)): " << inv_cond(m.topLeftCorner(3,3)) << endl; 18 cout << "inv_cond(m+I): " << inv_cond(m+Matrix4f::Identity()) << endl; 19 } 20
