Seth Axen 🪓 @sethaxen.com · 29/09/2026My first time visiting Germany from the US, I was in awe at how punctual, quiet, and smooth the trains were (looking at you SF BART). I was surprised at how critical Germans were of DB; didn't they know how good they had it? After traveling by train in Switzerland, I get it now. 110
Reposted by Seth Axen 🪓Aki Vehtari @avehtari.bsky.social · 09/09/2026A FAQ is what to do in case of high Pareto-k's with PSIS-LOO or PSIS-LOGO. In case of hierarchical models we can integrate out group specific parameters before PSIS. We investigated reliability of some alternative integration methods with the eventual goal of automating this arxiv.org/abs/2609.05713 1233
Seth Axen 🪓 @sethaxen.com · 21/07/2026Great write-up and comparison! I'd also completely forgetting about my original idea and write-up, so thanks @spinkney.bsky.social for improving it and showing it works well in practice! 270
Seth Axen 🪓 @sethaxen.com · 21/07/2026I don't post here very often, so I think it's worth checking in here to note that since I wrote this, I've transitioned to a heavy agent-based dev workflow. Partially that's due to a huge improvement in the models, partially due to some useful skills/harnesses. 1341
Seth Axen 🪓 @sethaxen.com · 26/06/2026That feeling when you join a weekly video group check-in with your strength training coach, and the very first word you hear is "Bayesian"... 🤗 120
Reposted by Seth Axen 🪓TMLR Published Papers @tmlr-pub.bsky.social · 09/04/2026Amortized Bayesian Workflow Chengkun LI, Aki Vehtari, Paul-Christian Bürkner et al. Action editor: Tom Rainforth openreview.net/forum?id=osV7adJlKD #mcmc #generative #amortized 033
Reposted by Seth Axen 🪓ArviZ @arviz.bsky.social · 19/03/2026ArviZ 1.0 is out! We have refactored it to be more modular, flexible & lightweight. For an overview of the changes, check the migration guide. python.arviz.org/en/stable/us...python.arviz.orgGetting started — ArviZ 1.0.0 documentation 21510
Reposted by Seth Axen 🪓Rafe Meager (they/them) @economeager.bsky.social · 12/03/2026"Other extensions of the factorial function do exist, but the gamma function is the most popular and useful. " did the gamma function herself/itself write this 2638
Seth Axen 🪓 @sethaxen.com · 12/03/2026Anyone aware of a collection of agent skills tailored towards FOSS workflows for package development and maintenance? Strongly considering writing my own. 111
Reposted by Seth Axen 🪓Aki Vehtari @avehtari.bsky.social · 04/03/2026If you have been using LOO-PIT, this is a must read for you! @herman-tesso.bsky.social has done excellent work with this paper! Thanks for @florencebockting.bsky.social and @aloctavodia.bsky.social for getting this to bayesplot and ArviZ. I'll notify when I have my casestudies updated with this 0162
Seth Axen 🪓 @sethaxen.com · 28/01/2026I've been seeing some folks recently explain how they're using agent-based workflows to help manage their life/work. I think it's great that people are sharing this and probably super useful for some. But I still haven't seen a use case that would be helpful for me. 141
Seth Axen 🪓 @sethaxen.com · 07/01/2026Over the break I was picking away at a personal project where brms is clearly the best tool to use, and hot damn, is brms nice! 0101
Seth Axen 🪓 @sethaxen.com · 03/01/2026Introduce yourself as what almost killed you: Hi there, I'm a hernia 010
Reposted by Seth Axen 🪓Demetri @phdemetri.bsky.social · 26/11/2025I believe eigen fly. I believe eigen touch the sky. 324042
Seth Axen 🪓 @sethaxen.com · 24/11/2025I was pleasantly surprised to find that a TMLR paper last year (openreview.net/forum?id=Kre...) cited in one of their proofs my blog post on injectivity radii for unitary groups (sethaxen.com/blog/2023/02...).openreview.netWrapped $\beta$-Gaussians with compact support for exact...We introduce wrapped $\beta$-Gaussians, a family of wrapped distributions on Riemannian manifolds, supporting efficient reparametrized sampling, as well as exact density estimation, effortlessly... 120
Seth Axen 🪓 @sethaxen.com · 24/11/2025Finally got around to trying out @typst.app, and I'm really surprised how easy the learning curve coming from TeX has been! I'm still not convinced it has all of the features I would want to replace TeX for papers, but it might replace my current TeX-in-MD derivation workflow. 290
Seth Axen 🪓 @sethaxen.com · 21/11/2025Updating CUDA on my desktop machine today, thoughts and prayers appreciated. 1130
Seth Axen 🪓 @sethaxen.com · 19/11/2025I've been experimenting with using Conventional Commits on some of my repos, and I think I'll start using it everywhere. I found it helps me structure my self-contained commits and spot when which changes were made where more easily. www.conventionalcommits.org/en/v1.0.0/conventionalcommits.orgConventional CommitsA specification for adding human and machine readable meaning to commit messages 280
Reposted by Seth Axen 🪓ML for Science @ml4science.bsky.social · 13/11/2025Great new work from the labs of @jakhmack.bsky.social and @philipp.hertie.ai! The software Jaxley enables brain simulations which both imitate the processes in the brain in detail and can solve challenging cognitive tasks. Press release of @unituebingen.bsky.social: uni-tuebingen.de/en/universit...uni-tuebingen.deSoftware optimizes simulations of the brain 0164
Reposted by Seth Axen 🪓BenjMurrell @benjmurrell.bsky.social · 10/11/2025We figured out flow matching over states that change dimension. With "Branching Flows", the model decides how big things must be! This works wherever flow matching works, with discrete, continuous, and manifold states. We think this will unlock some genuinely new capabilities. 42413
Reposted by Seth Axen 🪓Diana Cai @dianarycai.bsky.social · 27/10/2025Fisher meets Feynman! 🤝 We use score matching and a trick from quantum field theory to make a product-of-experts family both expressive and efficient for variational inference. To appear as a spotlight @ NeurIPS 2025. #NeurIPS2025 (link below) 1469
Seth Axen 🪓 @sethaxen.com · 24/10/2025Yesterday I asked the 7-year-old how he would describe what I do for work. His response: "You do math all day, get paid for no reason, and print things." 160
Seth Axen 🪓 @sethaxen.com · 02/10/2025"I'm sure I don't have to tell you that #JuliaLang is awesome and Matlab is not" #HeardAtJuliaCon #JuliaCon 2211
Reposted by Seth Axen 🪓MC Stan @mc-stan.org · 17/09/2025MC Stan is here! Follow for the latest Stan news, and tag if you want us to repost your posts about new papers, packages, courses, etc. about Stan 13831
Reposted by Seth Axen 🪓sbi - Simulation-based inference @sbi-devs.bsky.social · 09/09/2025From hackathon to release: sbi v0.25 is here! 🎉 What happens when dozens of SBI researchers and practitioners collaborate for a week? New inference methods, new documentation, lots of new embedding networks, a bridge to pyro and a bridge between flow matching and score-based methods 🤯 1/7 🧵 12916
Reposted by Seth Axen 🪓Charles Margossian @charlesm993.bsky.social · 10/09/2025My paper with Loucas Pillaud-Vivien and Lawrence Saul, “Variational Inference for Uncertainty Quantification: An Analysis of Trade-offs”, has been accepted for publication in the Journal of Machine Learning Research. 📃 arxiv.org/abs/2403.13748 🧵 1/ 1165
Seth Axen 🪓 @sethaxen.com · 08/09/2025Working from home and overhearing my 7-year-old trying to explain "countable infinity" to my partner using donuts. 240
Reposted by Seth Axen 🪓Jan Boelts @janboelts.bsky.social · 18/08/2025Fun read of their amazing contributions to the SBI hackathon! 🥐 The SBI-Pyro bridge that @sethaxen.com built has a lot of potential I believe. I'll actually be presenting this work at @euroscipy.bsky.social this Wednesday - excited to share this with a broader audience. euroscipy.org/talks/KCYYTF/euroscipy.orgPyro Meets SBI: Unlocking Hierarchical Bayesian Inference for Complex SimulatorsThe EuroSciPy meeting is a cross-disciplinary gathering focused on the use and development of the Python language in scientific research. 051
Reposted by Seth Axen 🪓Aki Vehtari @avehtari.bsky.social · 02/08/2024All three books I've co-authored are freely available online for non-commercial use: - #Bayesian Data Analysis, 3rd ed (aka BDA3) at stat.columbia.edu/~gelman/book/ - #Regression and Other Stories at avehtari.github.io/ROS-Examples/ - Active Statistics at avehtari.github.io/ActiveStatis... 7368145
Seth Axen 🪓 @sethaxen.com · 11/08/2025Pro-tip: don't be the poor sod that adds a daily cron trigger to a GitHub Actions workflow that often fails. Long after you've left the project, you will get *daily* failure notifications, and the only way out is to trick some other poor sod into editing the workflow. docs.github.com/en/actions/c... 010
Seth Axen 🪓 @sethaxen.com · 08/08/2025Like the authors, I also found this result disturbing. The crux is that *conditioning* a distribution to lie on a manifold is *not* in general the same thing as *restricting* the distribution to the manifold (i.e. constraining the support and re-normalizing). 140
Seth Axen 🪓 @sethaxen.com · 05/08/2025Finally, a part of my Fairphone 5 stopped working. For any other phone, I'd be dropping >500€ right now to replace it with a marginally better brand new phone that would last me just 2-3 years. Instead, I paid 41€, had the new part in 4 days, replaced it in 5 minutes, and the phone is good as new! 150
Seth Axen 🪓 @sethaxen.com · 31/07/2025Sharing this here a bit late, but @vstaros.bsky.social and I wrote a little something about our experience contributing to the @sbi-devs.bsky.social (simulation-based inference) hackathon. @mlcolab.org @mackelab.bsky.social We were obviously very hungry while writing.mlcolab.orgA retrospective on the 2025 SBI HackathonYou walk into a bakery, take one bite of a still-warm pastry, and think: “Whoa - there’s rye flour, a hint of orange zest, maybe cardamom… and is that buckwheat honey?” From that single taste you begi... 0113
Seth Axen 🪓 @sethaxen.com · 24/07/2025Spent a pleasant morning organizing GitHub repos and notifications, responding to issues and PRs, and answering questions on Slack. Reminder that FOSS is often about building a community as much as building software! 170
Reposted by Seth Axen 🪓Martin Trapp @trappmartin.eurosky.social · 21/07/2025Remember that computers use bitstrings to represent numbers? We exploit this in our recent @auai.org paper and introduce #BitVI. #BitVI directly learns an approximation in the space of bitstring representations, thus, capturing complex distributions under varying numerical precision regimes. 2223
Seth Axen 🪓 @sethaxen.com · 15/07/2025If you run a DuckDuckGo search for "qr decomposition", it returns a QR code for "decomposition". 1110
Reposted by Seth Axen 🪓Michael Kirchhof @mkirchhof.bsky.social · 03/07/2025Can LLMs access and describe their own internal distributions? With my colleagues at Apple, I invite you to take a leap forward and make LLM uncertainty quantification what it can be. 📄 arxiv.org/abs/2505.20295 💻 github.com/apple/ml-sel... 🧵1/9 1236
Seth Axen 🪓 @sethaxen.com · 07/06/2025Normalize v1.0 of software adding no new features. 1.0 comes with an expectation of greater stability than pre-1.0 releases. Debuting new features in that release makes it less stable, not more. Put the new features in an earlier release and let them stabilize *before* the 1.0. 0243
Seth Axen 🪓 @sethaxen.com · 02/06/2025I strongly suspect my 4-year-old has figured out how to vomit at will so he can stay home from preschool and "watch TV." 020
Reposted by Seth Axen 🪓Philipp Berens @philipp.hertie.ai · 23/05/2025We are incredible happy to be able to continue our work of developing new #AI4science across a wide range of disciplines with incredible colleagues in #physics, #neuroscience, #cogsci, #geoscience, #linguistics, #economics, #medicine, #philosophy, #law and #anthropology! @unituebingen.bsky.social 1395
Seth Axen 🪓 @sethaxen.com · 23/05/2025I am literally begging you, if in your paper you summarize the features of software *that you do not use*, at the bare minimum have a user of that software (even better, a maintainer) look over that bit of text before submitting. Sincerely, tired-of-software-I-worked-on-being-misrepresented 240
Reposted by Seth Axen 🪓Claire Vernade @claireve.bsky.social · 04/05/2025Amazing Best Paper award talk on Variational inference theory by Charles Margossian @charlesm993.bsky.social at #aistats What does VI learn and under which conditions? -> arxiv.org/pdf/2410.11067 0162
Seth Axen 🪓 @sethaxen.com · 28/04/2025From Student's "Errors of Routine Analysis" (1927) doi.org/10.2307/2332... 032
Reposted by Seth Axen 🪓Aki Vehtari @avehtari.bsky.social · 23/04/2025A new paper with Alex Cooper and Catherine Forbes "Joint leave-group-out cross-validation in Bayesian spatial models" arxiv.org/abs/2504.15586 (Alex did the hard work for this, and running many cross-validation simulations with spatial models is hard) 1195
Seth Axen 🪓 @sethaxen.com · 14/04/2025Phew! US Taxes filed. While they're generally not fun to do, it's extra not fun when you're an expat and only have to do it to avoid being double-taxed while all the immigrants from other countries don't have to file taxes in their home countries. 020
Seth Axen 🪓 @sethaxen.com · 04/04/2025o1 musing to itself in German: "Sister, I am working on considering all possibilities." 2113