setup_eigen.md

How to Set Up Eigen Library

Namely, you can set up Eigen in three ways:

• download eigen using a package manager (for Mac and Ubuntu)
• download the repository and configure.
• clone the repository and configure

Below, we discuss these options in detail

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Install using a Package Manager

for Mac, install eigen using package manager brew as

$ brew install eigen

For ubuntu, install eigen using apt-get as

$ sudo apt-get install libeigen3-dev

Unfortunately, for windows, there is not a easyway to install eigen with commands.

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Download & Configure

Download the repository from here

http://eigen.tuxfamily.org/index.php?title=Main_Page#Download

1. Download the compressed file (e.g., eigen-3.*.*.zip) and extract it. This result in a directory eigen-3.*.*
2. Put the extracted file under the 3rd_party directory as delfem2/3rd_party/eigen-3.*.* .

Then type the commands below

cd delfem2/3rd_party/eigen-3.*.* # move to the directory
mkdir build # make a new directory for "out-of-source build"
cd build    # move to the new directory
cmake ..    # configure (this may take one or two minutes)
cmake --install . --prefix ../../Eigen_Lib  # copy configured files to "Eigen_Lib"

Make sure you have a header file Dense at

delfem2/3rd_party/Eigen_Lib/include/eigen3/Eigen/Dense

Clone & Configure

Basically it is similar to the "Download & Configure" approach. The only difference is that instead of download we use submodule to clone the Eigen repository.

$ git submodule update --init 3rd_party/eigen # clone the "eigen" repository
$ cd 3rd_party/eigen # move to the eigen repository
$ mkdir build # make a directory for "out-of-source build"
$ cd build    # move to the new directory
$ cmake ..    # configure (this may take one or two minutes)
$ cmake --install . --prefix ../../Eigen_Lib # copy files into the "Eigen_Lib" folder

Make sure you have a header file Dense at

delfem2/3rd_party/Eigen_Lib/include/eigen3/Eigen/Dense