Hello all,

I'm a newbie with Eigen2 and GCC 4.2.3 as well. I am currently having problems making gcc compile the examples from eigen2 and my 'hello world'-matrix examples.

According to the tutorial, installation is not required, nor CMake. However, When I installed the previous version (Eigen 1.0) through Ubuntu, I notice the header files were copied to the /include subdirectory.

Whenever I try to compile a program using a matrix, I get the message,
" error: Eigen/Core: file cannot be found".

Is it accurate what the tutorial on eigen.tuxfamily.org/dox.TutorialCore.html says? How is GCC aware of this classes? Does it really suffice to add "#include <Eigen/Core>" to the file that will use the matrix class? Shouldn't this class be installed?

I would really appreciate any help you may provide.

Cheers!!!

Bob.

Well, this is really a very general question about GCC usage not specific to eigen. Basically, when you do

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#include<foo>


GCC looks for "foo" in a list of directories called the "include path". By default, this is only a few system directories like /usr/include, but you can add more with the -I option. So if you have eigen2 in a ~/eigen2 directory, just do:

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c++ -I ~/eigen2 myprogram.cpp