#Eigen 3.0.5

This repository has been created to keep a backup copy of the Eigen 3.0.5 linear algebra template library to maintain support for ocra-core, namely the unsupported LGSM (Lie Group Solid Mechanics) library. The Eigen project can be found at http://eigen.tuxfamily.org/index.php?title=Main_Page.

##Install

Because Eigen consists entirely of header files there is no compilation to be done, you simply have to put everything in the "right" place.

So we start by deciding where we want to put our version of Eigen. If you already have other versions of Eigen installed then I would recommend putting Eigen somewhere local like: /home/user/... but this is up to you. For demonstration purposes let's say our user bob decides to put Eigen in /home/bob/code

First he clones the repo:

cd /home/bob/code
git clone https://github.com/ocra-recipes/eigen_3_0_5

Let's now call /home/bob/code/eigen_3_0_5/, $EIGEN_ROOT.

Now he just needs to make sure package config can find these headers. First he opens eigen3.pc and changes the CFlags to point to $EIGEN_ROOT:

Cflags: -I$EIGEN_ROOT -I$EIGEN_ROOT/unsupported

becomes...

Cflags: -I/home/bob/code/eigen_3_0_5 -I/home/bob/code/eigen_3_0_5/unsupported

Great! Now he just has to tell pkgconfig about this new file. To do so there he has two options:

1. Copy the eigen3.pc file to the pkgconfig folder.

sudo cp $EIGEN_ROOT/eigen3.pc /usr/share/pkgconfig

2. Add $EIGEN_ROOT to the pkgconfig path in the .bashrc.

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/home/bob/code/eigen_3_0_5

And that is it.

##Warning If you already have Eigen 3.XX then this will cause a direct conflict. You have been warned!