Adding Eigen library to Dev-C++

Hey all, I'm a MATLAB user at work but I'm trying to do some independent projects so I've started learning C++. The Eigen library looks like it has a lot of the matrix/vector functions I'm used to, but I'm having trouble getting it to work.

According to the website (, I only need to make sure the compiler can find the Eigen header files. I'm using Dev-C++ 5.6.0 (Orwell), and I've looked around the internet for how to do this but have yet to find anything helpful. I've tried placing the files in the MinGW include folder and adding the path via -I command in the compiler but those haven't worked.

I have no experience adding libraries and templates so any pointers would be appreciated. I've included the recommended test code below, when I try to compile it says there's no such file or directory for Eigen/Dense

#include <iostream>
#include <Eigen/Dense>
using Eigen::MatrixXd;
int main()
MatrixXd m(2,2);
m(0,0) = 3;
m(1,0) = 2.5;
m(0,1) = -1;
m(1,1) = m(1,0) + m(0,1);
std::cout << m << std::endl;

Thanks, J
In Orwell DevC++ try this. From the main menu, select tools->compiler options
A window should be displayed with further options. Select the "Directories" tab, then the "C++ Includes" tab. At the bottom-right of the panel, is an icon to click in order to browse to the directory where the Eigen files are located. In my case it was F:\temp, click add and ok then try to compile your program. it should now be able to find the files and build / run your program.
Ok that worked, thanks Chervil!
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