Reproducible Spectrum and Hyperspectrum Data Analysis Using NeXL

Abstract

NeXL is a collection of Julia language packages (libraries) for X-ray microanalysis data processing. NeXLCore provides basic atomic and X-ray physics data and models including support for microanalysis-related data types for materials and k-ratios. NeXLMatrixCorrection provides algorithms for matrix correction and iteration. NeXLSpectrum provides utilities and tools for energy-dispersive X-ray spectrum and hyperspectrum analysis including display, manipulation, and fitting. NeXL is integrated with the Julia language infrastructure. NeXL builds on the Gadfly plotting library and the DataFrames tabular data library. When combined with the DrWatson package, NeXL can provide a highly reproducible environment in which to process microanalysis data. Data availability and reproducible data analysis are two keys to scientific reproducibility. Not only should readers of journal articles have access to the data, they should also be able to reproduce the analysis steps that take the data to final results. This paper will both discuss the NeXL framework and provide examples of how it can used for reproducible data analysis.

Strategies for Standardizing EDS Measurements

“…Removing spectra with high scores and recomputing the metric for each remaining spectrum allows you to iteratively evaluate a set of spectra until a self-consistent set is found. This strategy has been implemented in DTSA-II's Spectrum Bundler [2] and in NeXLSpectrum's similarity(…) and findsimilar(…) functions [3] (https://github.com/usnistgov/NeXLSpectrum.jl). In practice, careful measurements on ideal samples will produce metrics that are close to unity.…”