Chris Rackauckas
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chrisrackauckas.bsky.social
Chris Rackauckas
@chrisrackauckas.bsky.social
Lead dev of SciML org, VP of Modeling and Simulation @JuliaHub, Director of Scientific Research @PumasAI, and Research Staff
@mit_csail. #julialang #sciml
BLIS is a really slow BLAS lol
August 4, 2025 at 6:23 PM
New paper on fitting #neuroscience models to neuroimaging and electrophysiological data! We show that the previous techniques within the field (Spectral DCM) can be greatly improved using automatic differentiation, #julialang #sciml, ModelingToolkit, and more.
July 25, 2025 at 11:33 AM
We can learn dynamical systems that capture the correct statistical properties of the original system, and use symbolic regression to sparsify the results to predicted governing equations. Use case: learning neural mass models, i.e. models of average behaviors of large brain regions
July 9, 2025 at 10:29 AM
However, we can force the perturbed model to be non-chaotic, making the fitting process orders of magnitude easier. It also gives a smooth loss landscape with less or no bad local minima.
July 9, 2025 at 10:29 AM
So how did we overcome this? By making a non-chaotic training of course! We instead fit a perturbed model with the curious behavior that it retains the same global optima, i.e. the correct fitting parameters of the perturbed model is also a correct fitting model of the original model.
July 9, 2025 at 10:29 AM
Our new manuscript shows how to extend automated model discovery and universal differential equations to chaotic systems in #neuroscience using a trick from control literature known as the Prediction Error Method (PEM)!

Check out the paper at: arxiv.org/abs/2507.03631

#sciml #ai4science
July 9, 2025 at 10:29 AM
It is built upon the #julialang #sciml ecosystem, meaning the generated code is accessible and easily re-targetable. You can write your own backends, force the usage of #gpu acceleration, do differentiable programming, etc.
June 18, 2025 at 10:30 AM
Dyad comes with #VSCode extensions to seamlessly perform static analyses for furthering model correctness by ensuring the physics is correct before code generation.
June 18, 2025 at 10:30 AM
With modeling heat pumps and dehumidifiers, we were able to show that the latest boundary value problem (#BVP) solvers in #julialang #sciml outperform the Fortran wrapped bvp_solver of SciPy and the native bvp4c/5c solvers of MATLAB.

Published article here: authors.elsevier.com/c/1lHcein8Vr...
June 18, 2025 at 10:20 AM
New blackbox global optimization benchmarks shows that the #julialang BlackBoxOptim.jl (BBO) outperforms the classic C-based NLopt on a wide array of difficult optimization problems.

See the benchmarks for more details: docs.sciml.ai/SciMLBenchma...

#optimization #machinelearning #C #python
May 31, 2025 at 10:54 AM
Earn money working on open source software #oss! New project just posted: help make wrappers to connect Symbolics.jl to SymPy. $300 bounty. Information for signing up for the #SciML small grants program are contained in the link:

sciml.ai/small_grants...

#julialang #python #symbolics #sympy #ode
May 29, 2025 at 9:20 AM
Using higher order automatic differentiation to improve stiff ODE solvers? Using a third order Newton-like method (Halley's) inside the #sciml #julialang ODE solvers with Taylor-mode AD, ~25% faster.

arxiv.org/abs/2501.16895
January 29, 2025 at 10:15 AM
We demonstrate this on a turbofan jet engine, achieving 0.1% relative error through an active learning process. This is one of the JuliaHub #julialang demonstrations from #scitech showcasing the advancements of industrialization of #SciML in #JuliaSim
January 16, 2025 at 8:13 AM
This new Radau method achieves state of the art performance on many highly stiff ODEs when high accuracy is needed, outperforming the classic #fortran and #c++ libraries as well as a lot of recent #julialang #sciml improvements!
December 20, 2024 at 2:38 AM
Outperforms the classic Hairer Fortran implementation of radau by about 2x across the board!
December 20, 2024 at 2:38 AM
New version of a very good ODE solver today! IRKGaussLegendre released a SIMD and multithreaded mode. 16th order Implicit Runge-Kutta integrator IRKGL16 for non-stiff symplectic equations which require high accuracy.
For more benchmarks, see the github.com/SciML/IRKGau...

#julialang #sciml #ode
November 9, 2024 at 3:20 PM
Wanted to get paid to contribute to open source? Help update scientific models in benchmarks of equation solvers (differential equations, nonlinear optimization, physics-informed neural networks) and collect some dough while doing so! See the link below for details.

#julialang #pinn #sciml
November 4, 2024 at 11:01 AM
PumasAI named Best Clinical Pharmacology Technology Firm by the 9th Annual Biotechnology Awards! This demonstrates the power of translating #julialang #sciml to industrial practice, building a new foundation of clinical pharmacology.
May 10, 2024 at 11:40 PM
Differentiable Metropolis-Hastings: differentiate through Bayesian estimation to optimize models towards achieving desired probabilistic outcomes, with implementation in #julialang (#sciml)

For more information, see arxiv.org/abs/2306.07961
April 14, 2024 at 4:07 PM
New structural identifiability analysis features: automatically reparameterize an ODE system to find the best way to make a system easier to learn with #julialang #SciML differentiable programming! For more, leave a star at github.com/SciML/Struct... and check out the tutorial
April 13, 2024 at 11:42 AM
#julialang GPU-based ODE solvers which are 20x-100x faster than those in #jax and #pytorch? Check out the paper on #sciml DiffEqGPU.jl. Instead of relying on high level array intrinsics that #machinelearning libraries use, it use a direct kernel generation!.

www.sciencedirect.com/science/arti...
December 25, 2023 at 1:58 PM
#julialang #sciml for perfume engineering. Mixing physical models with machine learned quantities in order to predict and classify odors.

chemrxiv.org/engage/chemr...
December 23, 2023 at 7:21 PM
New open source tool from JuliaHub: static code analysis to prove that a #julialang code is allocation-free. Use this to ensure that codes are safe for real-time applications, such as how we use it for JuliaSim to analyze #SciML control codes!

github.com/JuliaLang/Al...
November 18, 2023 at 6:02 PM
Direct results for the GPU performance of #julialang #sciml vs #jax vs #pytorch.

To use the code, check out the documentation at docs.sciml.ai/DiffEqGPU/st...
November 18, 2023 at 5:02 PM
Hey #julialang, trying the new app! First thing to share is I did a #sciml #systembiology #computationalbiology podcast where I talked about Julia, SciML, and Catalyst.jl.

See the episode: lnkd.in/eGTWnBit
November 11, 2023 at 10:17 PM