1.Eigen 下载The latest stable release is Eigen 3.4.0.的tar.gz的那个

2.直接解压：sudo tar -xvzf eigen-3.4.0.tar.gz

3. cmake编译+install 安装+将eigen文件复制到本地调用文件夹中 /usr/include

    cd eigen-3.4.0

    sudo mkdir build

    cd build

    sudo cmake ..

    sudo make install

    sudo cp -r /usr/local/include/eigen3 /usr/include

4.版本检查

pkg-config --modversion eigen3