PySM 3.4.4 Released with New SZ Models and NumPy 2 Support

openscience
pysm
python
Author

Andrea Zonca

Published

April 2, 2026

PySM 3.4.4 is now available both on PyPI and on conda-forge. This release is mostly about extending the Sunyaev-Zeldovich model suite and making sure PySM works cleanly with NumPy 2.

The main addition is a new set of SZ presets:

The published PySM documentation now includes the notebook I added to compare the WebSky and Agora SZ templates:

https://pysm3.readthedocs.io/en/latest/preprocess-templates/verify_templates/compare_websky_agora_sz.html

If you want the short reference page for these presets, see the SZ section in the models documentation:

https://pysm3.readthedocs.io/en/latest/models.html#sunyaevzeldovich-emission

On the compatibility side, PySM 3.4.4 adds NumPy 2 support by replacing the deprecated np.trapz call with numpy.trapezoid. This is the main change needed for users upgrading scientific Python environments to NumPy 2 while keeping PySM in their pipeline.

The full release notes are on GitHub:

https://github.com/galsci/pysm/releases/tag/3.4.4