In this instruction we explain how to install Python and all the necessary Python packages to be able to run BornAgain simulations via Python scripting.

We advertise this as an instruction for advanced users. However, it provides a much more lightweigth and cleaner environment than the bulky Python installation using Anaconda explained here.

This is actually the most complicated step since the default download button leads to a download of the 32-bit version which will not work with BornAgain. To download the correct version, click on the Windows link marked on sthe creenshot below.

On the new page you will find a list of Windows installers. Select the Windows x86-64 executable installer. Make sure that you are in the section corresponding to Python 3.9 .

## Run the installer

Run the installer. Please select Add Python 3.7 to PATH at the bottom of the screen and then push Install Now.

Adding Python to the PATH is an important step to be able to use Python from the command shell and various code editors.

## Install the required Python packages

BornAgain requires matplotlib and numpy to be installed in site-packages of your Python distribution. Start a Windows command shell by typing cmd in the Windows Start menu.

In the new opened window type

pip install matplotlib numpy


Pip is a package manager which is used in the Python world to manage packages in an existing Python installation. The command pip install matplotlib numpy starts the installation of the matplotlib library for plotting and the numpy library for matrix manipulation.

When the installation is complete the window should look like the screenshot below.

At this point Python and all the required dependencies are successfully installed.

### Validate Python and BornAgain installation

To validate that BornAgain is working nicely together with the installed Python, start a Windows command shell by typing cmd in the Windows Start menu. To validate the BornAgain installation, type

• python to start the Python interpreter
• import bornagain as a first command
• print(bornagain.GetVersionNumber()) to print the BornAgain version number on the screen.

If no errors are displayed and you also see the BornAgain version number printed on the screen, your installation is correct.

### Running BornAgain examples

To run a BornAgain example from the command line, launch a command shell again and type (or copy-and-paste) the command below to see a scattering image appearing on the screen.

python C:/BornAgain-1.19.79/Examples/scatter2d/CylindersAndPrisms.py


The used path implies that BornAgain was installed to the default location. If this was not the case, you will have to adjust the path to the BornAgain Python example accordingly.

This kind of manual launching of Python scripts is not very convenient for regular usage and should be considered rather as another validation step.

### Running BornAgain examples using a Python IDE

We have provided two more step-by-step tutorials to explain how to run BornAgain examples in a convenient manner using one of two integrated development environments.