Upgrade eigen to version 3.3.5 under Ubuntu 16.04

ubuntu16.04 adopt sudo apt-get install libeigen3-dev The download is 3.2.9 edition , At present, many software packages need eigen3.3.0 And above , So it needs to be upgraded eigen3, Download at ：http://eigen.tuxfamily.org/index.php?title=Main_Page
, This article downloads eigen3.3.5 edition , After downloading, go to eigen Under the table of contents , Installation steps ：
mkdir build
cd build
cmake …
sudo make install
sudo ldconfig -v