FDA (Fast Data Analyzer): A Versatile Python-Based Software for X-ray Absorption Spectra Analysis in In Situ Experiments at ALBA

Abstract FDA (Fast Data Analyzer) is a versatile software tool designed for the analysis of X-ray absorption spectra (XAS) and X-ray diffraction patterns (XRD), collected during in situ/operando experiments at the NOTOS and CLAESS beamlines of ALBA synchrotron. The program is coded in Python 3 and Qt5 and aims to provide an easy online tool for data reduction and visualization, able to correlate the obtained results with the time evolution, temperature, and electrochemistry quantities of interest on gaseous products. Apart from basic XAS capabilities (like deglitching, self-absorption correction, background subtraction, EXAFS extraction and Fourier transforming), FDA allows linear combination analysis, principal component analysis (PCA) and multi-curve resolution analysis (MCR), by using algorithms well established from scikit-learn, PyMca (python), or MCR-ALS toolbox (Matlab). In addition to these capabilities, FDA permits to visualize XRD patterns as one or two-dimensional plots. FDA is released as free and open-source software under MPL licence, ensuring broad accessibility and enabling further community contributions. The program is designed for portability and can run on common computer platforms such as Microsoft Windows, Macintosh OSX, Linux, and arm64 single-board computers.