You can check where the files were placed using: dpkg -L libeigen3-dev By default, Ubuntu installs the headers to /usr/include/eigen3/ . Method 2: Manual Download from Source
Open your terminal (Ctrl+Alt+T) and run: sudo apt update download eigen c++ ubuntu
Eigen is one of the most popular C++ template libraries for linear algebra, widely used for handling matrices, vectors, and complex numerical solvers. Because it is a , "installing" it on Ubuntu is significantly simpler than many other C++ dependencies, as it requires no pre-compilation. You can check where the files were placed