XMCD GUI#

polartools ships an interactive PyQt6 application for the common XMCD processing workflow. It’s installed as a console script when you pip install polartools, so you can launch it from anywhere:

xmcd-gui

It takes no arguments. For the other graphical tools in the package, see Scan viewers and Flyscan dichroism.

What it does#

Wraps the same functions documented in the XAS / XMCD example with a graphical workflow:

Load paired ±-field scans from a SPEC file or databroker catalog
Set the edge energy (E₀), pre-edge, and post-edge windows interactively
See the normalized XAS and XMCD update live as you adjust parameters
Save the processed XMCD to a column file with a metadata header

Independent ±H normalization#

As of v0.5.5, the +H and −H scans can be normalized independently — useful when the two field directions have different self-absorption or detector response. Toggle this from the Settings menu.

Running headless (CI / scripted use)#

The GUI uses Qt’s offscreen platform when QT_QPA_PLATFORM=offscreen is set — this is how the test suite exercises it without a display. Useful for scripted batch processing on a server, but for that workflow you’re usually better off calling polartools.absorption.process_xmcd directly.

Architecture#

The GUI is a single file: polartools/xmcd_gui.py. It’s intentionally thin — almost all the actual processing is delegated to functions in polartools.absorption. So if a scriptable equivalent of any GUI feature is useful, you can usually find it (or build it) in that module.

Reporting GUI bugs#

Open an issue with:

The polartools version (python -c "import polartools; print(polartools.__version__)")
The PyQt6 version (python -c "from PyQt6.QtCore import QT_VERSION_STR; print(QT_VERSION_STR)")
A screenshot of the failure if it’s visual
The full traceback from the terminal you launched xmcd-gui from