| Brian Silverman | 72890c2 | 2015-09-19 14:37:37 -0400 | [diff] [blame^] | 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 | } |