ADD: added other eigen lib

libs/eigen/doc/examples/TutorialLinAlgExSolveColPivHouseholderQR.cpp

@@ -1,17 +1,14 @@
 #include <iostream>
 #include <Eigen/Dense>
 
-using namespace std;
-using namespace Eigen;
-
 int main()
 {
-   Matrix3f A;
-   Vector3f b;
+   Eigen::Matrix3f A;
+   Eigen::Vector3f b;
    A << 1,2,3,  4,5,6,  7,8,10;
    b << 3, 3, 4;
-   cout << "Here is the matrix A:\n" << A << endl;
-   cout << "Here is the vector b:\n" << b << endl;
-   Vector3f x = A.colPivHouseholderQr().solve(b);
-   cout << "The solution is:\n" << x << endl;
+   std::cout << "Here is the matrix A:\n" << A << std::endl;
+   std::cout << "Here is the vector b:\n" << b << std::endl;
+   Eigen::Vector3f x = A.colPivHouseholderQr().solve(b);
+   std::cout << "The solution is:\n" << x << std::endl;
 }