Interpretable machine learning of photon attenuation in polymer composite shields: code and data

Code and data for the manuscript “Interpretable Machine Learning of Photon Attenuation in Polymer Composite Shields: Physics-Constrained Symbolic Regression Validated against Measurements”. The package contains the Phy-X/PSD reference dataset (6720 records: polyetherimide with eight metal-oxide fillers, 10 loadings, 84 photon energies from 0.015 to 15 MeV), the Geant4 cross-check points, the published measurements used for the external check, the scripts for the eight-constant per-element law, the baselines and the unconstrained and physics-scaffolded symbolic-regression searches (PySR), and all stored search runs. Every number reported in the paper can be reproduced from the stored runs; see README.md.