Compiler-Research Monthly Meeting [5 June 2025 at 17:00 CET/8:00PDT]
Vassil Vassilev
Our next meeting will be on 05 June 2025 at 17:00 Geneva (CH) Time .
We are happy to host Jonas Rembser.
Title: Differentiating RooFit likelihoods with Clad
Abstract: RooFit is a C++ software for statistical data
modeling that is part of ROOT. It is widely used by the High
Energy Physics (HEP) community, most notably the LHC
experiments. RooFits core feature is building and numerically
minimizing likelihood functions for parameter estimation (aka.
*fitting*). The minimization can be greatly sped up by using
reverse mode (Automatic Differentiation) AD, in particular for
fits with many parameters, as typical for the LHC experiments.
This presentation will tell the story of how AD was integrated
to RooFit powered by Clad, the AD
tool developed by Compiler Research. We will cover the
integration strategy, explain the particularities of AD in the
context of likelihood fits, and present benchmark results. The
presentation will wrap up by explaining the current limitations
and plans for the future. More information on AD in RooFit with
Clad can also be found in this blog post on
the ROOT
website.
Speaker: Jonas Rembser is a particle physicist
with a strong interest in data science and software development.
After working with the CMS experiment for his PhD in particle
physics, Jonas joined CERN in 2021 to work on the ROOT project. He
is takes care of the statistical analysis libraries in ROOT, such
as RooFit and Minuit 2, as well as the ROOT Python interface. His
other academic interests include differential programming and
financial markets.
Feel free to forward this email to everybody who might be
interested. This talk will be recorded.
Vassil