Getting Started

Virtual Environments

We strongly recommend you to use python’s virtual environments to manage your python packages. Virtual environments allow you to isolate the python packages you need for each project and prevent conflicts between the dependencies of different projects. One way of creating and virtual environments using venv is given below:

1. make sure that you have venv installed, e.g. on Ubuntu the python3-venv apt-package

2. create a new virtual environment in your current directory with

   python3 -m venv .venv
   

   This will now create a .venv directory which can contain python packages and executables

3. activate the environment

   source .venv/bin/activate
   

   This will now cause python and pip to use this environment, as well as make any executables in that environment available in your PATH.

Installing GVEC

In the best case, GVEC can be installed with its python bindings using:

pip install gvec

For system requirements and more information see the installation page.

To confirm GVEC is installed and working, call pygvec --version in the terminal, or import gvec in a python session.

On the tutorials

Each subsection is a Jupyter notebook, displayed after its execution. You can follow the link in the right sidebar to download or browse the source code.

We recommend going through the notebooks in the order of this section.

You can also simply download all notebooks as a zip file.

The available tutorials are:

• Elliptic Tokamak

• Elliptic Stellarator

• Boozer transform

• Radial grid refinement via stages

• Prescribe a current profile

• Postprocessing

Running Jupyter notebooks

The GVEC tutorials are mostly organized in Jupyter notebooks (also called ipython notebooks). You can however also follow along with a normal python script.

To use the notebooks you need to have the following packages installed:

pip install jupyter ipykernel ipympl ipywidgets matplotlib

We recommend two options for running Jupyter notebooks:

1. Visual Studio Code with the jupyter extension

2. The jupyter notebook browser interface

   Here need to make the virtual environment visible (.venv must the activated!) with

   python3 -m ipykernel install --user --name .venv
   

   and then start

   jupyter notebook &
   

When you open a notebook, you should be prompted which kernel to use. Select the environment where you installed gvec, e.g. .venv.