Installation
This section provides a short guide on how to install required components of ViPErLEED.
Installing the ViPErLEED ImageJ plugins
The installation instructions for ImageJ and the ViPErLEED plugins can be found in the ViPErLEED ImageJ plugins section.
Installing Python
With the exception of the ViPErLEED ImageJ plugins, ViPErLEED requires a working Python installation. You can install Python using a package manager or as binary from the Python website.
Note
ViPErLEED requires Python 3.7 or newer, though we recommend using the latest available Python version.
We suggest Windows users to follow the notes in the official Python documentation: use the full installer, and include the Python Launcher for Windows.
Installing the ViPErLEED Python package
ViPErLEED is available on the Python Package Index (PyPI)
and can be installed using the Python package manager pip. We recommend
installing ViPErLEED in a
virtual environment
for easier dependency management. See also Using a Python virtual environment.
To install ViPErLEED from PyPI using pip, run
python -m pip install viperleed
in your terminal.[1]
This will install the latest version of ViPErLEED and all required
dependencies. It will also automatically install the
ViPErLEED command-line tools which can be called
from the terminal using the viperleed command. The viperleed.calc package for
LEED-I(V) calculation has also some non-Python dependencies that can be
installed as described in Installing tensor-LEED dependencies.
If you want to also install the dependencies for running the ViPErLEED graphical user interface, which also allows you to measure LEED-I(V) data, run
python -m pip install viperleed[GUI]
in your terminal.
Windows Subsystem for Linux
To run viperleed.calc under Windows, we recommend using the
Windows Subsystem for Linux (WSL), available starting from
Windows 10. Running viperleed.calc natively on Windows is possible, but experimental
and not recommended.
Note
The ViPErLEED graphical user interface, used, e.g., for acquiring LEED-I(V) measurements, runs natively on Windows, and does not require WSL.
Installing WSL may require enabling some “developer” features (especially
on Windows 10). To this end, open the Run dialog (Win+R),
type optionalfeatures, then press Enter. Make sure that
Virtual Machine Platform and
Windows Subsystem for Linux are selected in the
Windows Features dialog. You may need to restart your computer
after selecting them. Then, on the Microsoft Store, download your preferred
Linux distribution (e.g., Ubuntu). Once your distribution is downloaded,
you can install it by clicking on it. Follow the instructions in the terminal
to create a new user (note: user names should be lowercase only). You can then
start WSL by typing
wsl
in your terminal. You can find more information about WSL on the official instructions by Microsoft.
Using a Python virtual environment
A Python virtual environment is a confined workspace in which Python dependencies can be installed without affecting other components of the system. Several packages exist to create and manage virtual environments. We list short instructions for a few of them below.
venv
venv is not the most popular virtual-environment package, but has the
advantage of being distributed as part of the Python standard library and
thus requires no external dependencies.
Tip
It is a good idea to collect multiple virtual environments into one root directory of your choice. This makes it easier to switch between virtual environments later on.
To create a new virtual environment, navigate in your terminal to the path where you would like the virtual-environment to be saved:
cd <path/to/folder/where/virtual/environment/should/be/saved>
cd "<path\to\folder\where\virtual\environment\should\be\saved>"
Then, create a fresh virtual environment with
pythonX.Y -m venv <virtual_env_name>
py -X.Y -m venv <virtual_env_name>
where X.Y is the Python version of your choice. Note that this is the
version of Python that will be available (via python, or, on Windows,
also py) in the virtual environment just created.
Virtual environments must be activated before they can be used:
source "path/to/<virtual_env_name>/bin/activate"
call "path\to\<virtual_env_name>\Scripts\activate.bat"
To disable a virtual environment, call deactivate instead.