mirror of
https://gitlab.com/libeigen/eigen.git
synced 2024-12-21 07:19:46 +08:00
20 lines
594 B
C++
20 lines
594 B
C++
|
#include <iostream>
|
||
|
|
#include <Eigen/SVD>
|
||
|
|
using namespace Eigen;
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
float inv_cond(const Ref<const MatrixXf>& a)
|
||
|
|
{
|
||
|
|
const VectorXf sing_vals = a.jacobiSvd().singularValues();
|
||
|
|
return sing_vals(sing_vals.size()-1) / sing_vals(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
Matrix4f m = Matrix4f::Random();
|
||
|
|
cout << "matrix m:" << endl << m << endl << endl;
|
||
|
|
cout << "inv_cond(m): " << inv_cond(m) << endl;
|
||
|
|
cout << "inv_cond(m(1:3,1:3)): " << inv_cond(m.topLeftCorner(3,3)) << endl;
|
||
|
|
cout << "inv_cond(m+I): " << inv_cond(m+Matrix4f::Identity()) << endl;
|
||
|
|
}
|