2026-08-13 –, Room 6
This presentation discusses the development of MatrixEquations.jl, a comprehensive Julia package for solving specialized matrix equations, including Lyapunov, Sylvester, and Riccati types. While these equations are fundamental to control systems analysis and synthesis, their utility extends across numerous scientific domains. The package’s impact is substantial: it serves as a critical dependency for over 60 packages within the Julia ecosystem and averages over 2,000 monthly downloads.
Reflecting on its status as my most successful software project to date, I look forward to sharing insights into its development—specifically regarding two distinct implementation challenges: achieving peak numerical performance by leveraging optimized, hardware-specific libraries, and providing generic functionality that supports Julia’s abstract type system to work seamlessly with arbitrary-precision and non-standard number types.
Andreas Varga received the diploma in control engineering in 1974 and the Ph.D. degree in electrical engineering in 1981, both from the University "Politechnica" of Bucharest (Romania). From 1974 to 1993 he have held various research positions at the Institute of Informatics Bucharest and at the Ruhr-University of Bochum. From 1990 to 1992 he worked at the Ruhr-University of Bochum as visiting research fellow in the framework of a fellowship award of the Alexander von Humboldt Foundation. From 1993 until his retirement in 2015 he worked at the German Aerospace Center (DLR) in Oberpfaffenhofen, where he was a Senior Scientist of the Institute of System Dyanmics and Control. Andreas Varga has been a visiting fellow at the Kyoto University (1994), California Institute of Technology (2000), Australian National University (2000), University of Hong Kong (2000), and University of Umea (2002, 2008).
The main research interests of Dr. Varga include the numerical methods for linear systems analysis and design (with special emphasis on model and controller reduction, descriptor systems, periodic systems, fault detection), and robust numerical software for computer aided control system design (CACSD). He authored two books, coauthored three books, coedited two books, published over 65 papers in refereed journals or book chapters, and have over 155 conference publications. During his active career (1974-2015) he was involved in several CACSD related software projects, being the developer of over 20 software packages implemented in Fortran and MATLAB. After his retirement he focussed on implementing free software in the Julia language, being the main author of 7 Julia packages.
Andreas Varga became in 2003 a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) "for contributions to the development of numerical methods for computer aided analysis and design of control systems". He served as Associate Editor for the IEEE Transactions on Automatic Control between 1997-1999 and served as Program Chairman or General Chair of several IEEE sponsored conferences (e.g., CACSD, CCA, ISIC, SYSTOL).