Obituary

It is with deep sadness and great appreciation that we bid farewell to Prof. Friedrich Leisch, Head of the Institute of Statistics at BOKU. Friedrich "Fritz" Leisch's life was characterised by a special dedication to statistics and an untiring commitment to the development of science. His death leaves a gap not only in the professional world, but also in the hearts of all those who were lucky enough to know and work with him.

After studying technical mathematics at the Vienna University of Technology, Fritz Leisch embarked on his academic career with determination and passion. His early contribution as an assistant at the Institute of Statistics and Probability Theory at the TU Vienna already showed his potential, which later manifested itself in his international reputation in the field of statistical computing. Joining the R Core Development Team in 1997 and becoming Secretary General of the R Foundation in 2002 underscored his commitment to the advancement of this important statistical language.

At the same time, Fritz Leisch completed his doctorate in applied mathematics in 1999 and his habilitation in statistics in 2005. These academic milestones were just the beginning of a successful career that has taken him around the world. His work as a Kurt Gödel Fellow at the University of Adelaide in Australia and later as a professor at the University of Munich are testimony to his international influence and his ability to bring people and ideas together.

Since his appointment as Professor at the Institute of Statistics at BOKU in 2011, Fritz Leisch has shaped academic life at our university. His involvement at all levels, whether as deputy head or later as long-standing head of the Department of Space, Landscape and Infrastructure, was characterised by his ability to build consensus and support all staff. His calm, friendly and structured manner made him a valued colleague and mentor to many.

Fritz Leisch's contribution to applied research, which he saw as the guiding principle of his work, is particularly noteworthy. His work on Sweave, a pioneering software concept for literate programming, and his research on finite mixture models and cluster analysis have had a lasting impact on the way we analyse and interpret our data.

In addition, Fritz Leisch was a dedicated teacher who supervised countless undergraduate, masters and PhD students, contributed significantly to the training of future generations of statisticians as a faculty member of two PhD schools, and introduced statistical methods into interdisciplinary projects.

His legacy lives on in numerous publications, software packages and scientific works. But even more important is his influence on the people he guided on their own academic journeys.

We acknowledge Fritz Leisch's life's work with sincere gratitude and will honour his memory. Our heartfelt condolences go out to his family at this difficult time.