Edwin Diday died on April 28, 2023 at the age of 83. He was elected ISI member in 1985.
He was Professor Emeritus of Exceptional Class at the prestigious University of Paris-Dauphine (Ceremade - Decision Mathematics Research Laboratory). He left a considerable body of work: nearly 200 publications including 14 books as author or editor. He directed 58 doctoral theses.
He had a profound impact on data analysis, both in France and internationally: his name remains associated with the dynamic clustering method that he developed in 1971 and that opened the way to local models, as well as to pyramidal classification (for the representation of overlapping classes). Starting in the late 1980s, he developed the paradigm of symbolic data analysis extending the classical forms of variables to intervals, distributions, classes, etc., to which he devoted his last two books (Technip, 2018 and Wiley, 2019). Edwin Diday was a tireless worker, a convener, in particular thanks to the congresses organized under his responsibility by Inria (National Institute for Research in Digital Science and Technology) in Versailles from 1977. These congresses allowed French statisticians to meet each other and to meet foreign colleagues of high level. He was one of the founders of the Société Francophone de Classification in 1977. He was the scientific director of the Eurostat projects "SODAS" and "ASSO" (17 teams from 9 European countries) until 2003. Until 2013, he was involved in a program of the US National Science Foundation on Symbolic Data Analysis (SDA) and was involved until 2019 with Beihang University, China, in a Major International Joint Research Project on Statistical Modelling Methods of Massive High Dimensional Mixed Data funded by the National Natural Science Foundation in China (NFSC).
He received in July 2022 in Porto, Portugal, the International Medal for Outstanding Research Achievements in Classification awarded by the International Federation of Classification Societies (IFCS).
Until his last days Edwin Diday remained active, often regretting that he was no longer allowed to supervise new Ph.D. students while he still had so many projects. Besides his eternal dynamism, he had a great curiosity and sensitivity, as well as a proverbial absent-mindedness, which contributed to make his personality so endearing. His colleagues will greatly miss Edwin Diday, in France and beyond.
Gilbert Saporta
