Build on Linux

In case you want to change stuff in the source code or want to achieve a local installation, you should proceed as follows. This concerns an installation of Netgen and NGSolve.

Prerequisites

Make sure that you have the following packages installed:

  • You need a recent compiler

  • We advise to have Python installed, in version 3.8 or higher (you can compile Netgen/NGSolve also without python support). Make sure to install according packages in their "dev"-version to have the suitable header files installed.

  • You will need tcl / tk in version >=8.5 Make sure to install according packages in their "dev"-version to have the suitable header files installed.

  • git (to get the sources)

  • cmake (>=3.16) for the build system

  • libxmu-dev (you might also need the xorg-dev package)

  • libglu (again, the "dev"-version)

  • liblapacke-dev

The following line should update/install all prerequisites on Ubuntu (you need root privileges):

sudo apt-get update && sudo apt-get -y install python3 python3-distutils python3-tk libpython3-dev libxmu-dev tk-dev tcl-dev cmake git g++ libglu1-mesa-dev liblapacke-dev libocct-data-exchange-dev libocct-draw-dev occt-misc libtbb-dev libxi-dev

Getting the source

Choose a directory where you want to install Netgen/NGSolve, which will be denoted as ${BASEDIR} in the following installation guide. Change into your base directory and clone the git repository.

export BASEDIR=~/ngsuite
mkdir -p $BASEDIR
cd $BASEDIR
git clone --recurse-submodules https://github.com/NGSolve/ngsolve.git ngsolve-src

Building from the source

Now we create folders for builds and installations.

mkdir $BASEDIR/ngsolve-build
mkdir $BASEDIR/ngsolve-install

Configuring

Change into the directory for builds and call cmake with a link to the source directory

cd $BASEDIR/ngsolve-build
cmake -DCMAKE_INSTALL_PREFIX=${BASEDIR}/ngsolve-install ${BASEDIR}/ngsolve-src

Building

Now, call

make

You may want to add "-jx" with x the number of threads you want to use for the compilation. If everything goes smooth you can install the resulting build calling

make install

Finishing the installation

Finally you have to set the environment variable NETGENDIR to the location of the executable, eg. by

export NETGENDIR="${BASEDIR}/ngsolve-install/bin"

or

setenv NETGENDIR "${BASEDIR}/ngsolve-install/bin"

(depends on your linux distribution). You may want to add the corresponding line to your .bashrc, s.t. it is automatically set whenever you log in into your bash-shell. To be able to start netgen from the command line, you have to add NETGENDIR to the PATH, eg. by

export PATH=$NETGENDIR:$PATH

or

setenv PATH "$NETGENDIR:$PATH"

When you want to run Python scripts, you also have to set PYTHONPATH to the appropriate directory:

export PYTHONPATH=$NETGENDIR/../`python3 -c "import os.path, sysconfig;print(os.path.relpath(sysconfig.get_path('platlib'), sysconfig.get_path('data')))"`

Everything together

For brave ones here is a complete copy/paste script to download, configure, build and install Netgen/NGSolve when all dependencies are already installed. Note that bash is assumed as environment here. There is absolutely no warranty that this will work, so use it at your own risk! In case this script is failing, please follow the procedure above before asking for help.

export BASEDIR=~/ngsuite
mkdir -p $BASEDIR
cd $BASEDIR && git clone https://github.com/NGSolve/ngsolve.git ngsolve-src
cd $BASEDIR/ngsolve-src && git submodule update --init --recursive
mkdir $BASEDIR/ngsolve-build
mkdir $BASEDIR/ngsolve-install
cd $BASEDIR/ngsolve-build
cmake -DCMAKE_INSTALL_PREFIX=${BASEDIR}/ngsolve-install ${BASEDIR}/ngsolve-src
make -j4
make install
echo "export NETGENDIR=${BASEDIR}/ngsolve-install/bin" >> ~/.bashrc
echo "export PATH=\$NETGENDIR:\$PATH" >> ~/.bashrc
export PYTHONPATH_TMP=`python3 -c "import os.path, sysconfig;print(os.path.relpath(sysconfig.get_path('platlib'), sysconfig.get_path('data')))"`
echo "export PYTHONPATH=\$NETGENDIR/../${PYTHONPATH_TMP}:\$PATH" >> ~/.bashrc
source ~/.bashrc
cd ${BASEDIR}/ngsolve-install/share/ngsolve/py_tutorials/intro
netgen navierstokes.py

Keep it up to date

To update Netgen/NGSolve go to the source directory (${BASEDIR}/ngsolve-src) and fetch the latest sources. The second line is needed to update all dependencies provided as git submodules (such as Netgen).

git pull
git submodule update --recursive --init

After that, go to the build directory (${BASEDIR}/ngsolve-build) and build/install again

make
make install