fatal error: Eigen/Dense: No such file or directory

在运行ORB-SLAM2+imu紧耦合算法时遇到的错误

fatal error: Eigen/Dense: No such file or directory

解决办法：

1.

cd /usr/local/include

2.

sudo ln -sf eigen3/Eigen Eigen

3.

sudo ln -sf eigen3/unsupported unsupporte

解决了

下一个错误：error:static assertion failed: YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY

解决办法：（参照网上博客）

打开Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h，将以下代码

 template 
 class LinearSolverEigen: public LinearSolver
 {
   public:
 typedef Eigen::SparseMatrix SparseMatrix;
typedef Eigen::Triplet Triplet;     typedef Eigen::PermutationMatrix PermutationMatrix;

改为：：：

template 
 class LinearSolverEigen: public LinearSolver
 {
   public:
     typedef Eigen::SparseMatrix SparseMatrix;
    typedef Eigen::Triplet Triplet;
    typedef Eigen::PermutationMatrix PermutationMatrix;

解决！

下一个错误：undefined reference to symbol '_ZN2cv6String10deallocateEv'

解决：在CMakeLists里面修改find_package(OpenCV 3 REQUIRED)把版本写成自己安装的就可以

错误：usleep was not declared

解决：#include 添加头文件即可

错误：关于ros的

解决：路径问题，编辑bashrc文件 

最后加上一句：export  ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:/home/z/catkin_ws/src/LearnVIORB-RT/Examples/ROS/ORB_VIO