MC Stan @mc-stan.org · 17/09/2026- New laplace_latent_solve(_tol) for getting the mean and covariance (Cholesky) of the modal normal approximation - The compiler has fewer dependencies, with a smaller binary size and improved speeds. 040
MC Stan @mc-stan.org · 17/09/2026- New functions to_vector_array, to_row_vector_array, and new overloads for to_matrix for arrays of (row-)vectors. - New poisson_binomial distribution - The same .stanfunctions can be #included multiple times without leading to errors about duplicated function definitions. 140
MC Stan @mc-stan.org · 17/09/2026Release of CmdStan 2.40, including new Stan Math, core Stan, and Stanc, is now available! Blog post with new features blog.mc-stan.org/2026/09/16/r... Highlights - integrate_1d_double_exponential, a variadic version of old integrate_1d - integrate_1d_gauss_kronrod, a different quadrature rule ...blog.mc-stan.orgRelease of CmdStan 2.40We are very happy to announce that the 2.40.0 release of CmdStan is now available on Github! As usual, the release of CmdStan is accompanied by new releases of Stan Math, core Stan, and Stanc3. Thi… 13016
MC Stan @mc-stan.org · 20/08/2026StanCon 2026 conference part is over and all the talks are available at StanCon 2026 playlist! 0145
MC Stan @mc-stan.org · 20/08/2026And the final uploaded talk in the StanCon playlist - John Ashley Burgoyne: Incorporating Response Times into Item Response Models 000
MC Stan @mc-stan.org · 20/08/2026- Soham Mukherjee: Latent variable estimation with composite Hilbert space Gaussian processes - Steve Bronder and Brian Ward: Stan developer talk 100
MC Stan @mc-stan.org · 20/08/2026- Ville Laitinen: An Introduction to Probabilistic Data Analysis with Stan on the Carpentries Platform - Zeno Romero: Probabilistic Matrix Completion for Chemical Engineering Applications ... 100
MC Stan @mc-stan.org · 20/08/2026- Aleksi Lahtinen: Probabilistic Ordinal Regression for Hierarchical Survey Data - Brian Ward: Understanding Stan so you can write JAX ... 100
MC Stan @mc-stan.org · 20/08/2026StanCon 2026 day 3 talks uploaded (link to playlist in the first post of this thread) - Fredrik Ronquist: Universal probabilistic programming for phylogenetics: challenges and opportunities - Jakob Torgander: simplexmcmc: an auxiliary-variable framework for mixed continuous-discrete posterior ... 100
MC Stan @mc-stan.org · 19/08/2026StanCon 2026 afternoon talks upload - Bob Carpenter "Within-orbit adaptive leapfrog sampler (WALNUTS) with continuous Nutpie adaptation" - Chandler Ross "Nonparametric SDEs for stability landscapes from sparse microbiome data" - Nils Rudi "Luck, skill, and the battle of the sexes: analyzing tennis" 130
MC Stan @mc-stan.org · 19/08/2026- Collin Cademartori "Variance deltas: Interactive visualizations for explaining Bayesian uncertainty" - Tim M. Szewczyk "Blending ensemble dispersal modelling with dynamic stage-structured population models: A coherent framework for sea lice infestation dynamics" 110
MC Stan @mc-stan.org · 19/08/2026- Pranav Sanke (on behalf of Jesse Piburn) "Embedding geographic concepts of place in probabilistic modelling of temporal activity patterns using Bayesian Dirichlet regression" - Anna Elisabeth Riha "To select or not to select - predictively consistent priors instead of model selection" ... 100
MC Stan @mc-stan.org · 19/08/2026StanCon 2026 Wednesday morning talks uploaded - @kaitejohnson9.bsky.social "Joint modelling to infer transmission and evolutionary dynamics of infectious diseases from multiple different data sources" - Jonas Wallin "Hierarchical Riemannian manifold Hamiltonian Monte Carlo algorithms" ...youtube.comStanCon 2026 Uppsala - YouTube 110
MC Stan @mc-stan.org · 18/08/2026Anna Dreber's keynote talk "(Predicting) replications and generalizability of (mainly experimental) social science results" is now available 110
MC Stan @mc-stan.org · 18/08/2026Talks by @javieraguilar.bsky.social, @spinkney.bsky.social and Nikolas Siccha uploaded 130
MC Stan @mc-stan.org · 18/08/2026There is now StanCon 2026 Uppsala playlist www.youtube.com/playlist?lis... At the moment talks by @mjskay.com, @aseyboldt.bsky.social, @paulbuerkner.com, @charlesm993.bsky.social are up, and we'll keep uploading more during the weekyoutube.comStanCon 2026 Uppsala - YouTube 23717
Reposted by MC StanAki Vehtari @avehtari.bsky.social · 18/08/2026 @mjskay.com starting the StanCon 2026 talks with "Systematic uncertainty visualization design (and its foundation in probabilistic models)" All talks are recorded and will be made available after the conference 0385
Reposted by MC StanAki Vehtari @avehtari.bsky.social · 18/08/2026 @florencebockting.bsky.social's guide "Contributing to Stan A Developer’s Guide to the Core, Interfaces, and First Contributions" at florence-bockting.github.io/stancon-cont...florence-bockting.github.ioContributing to Stan 052
Reposted by MC StanAki Vehtari @avehtari.bsky.social · 17/08/2026 @florencebockting.bsky.social starting the StanCon 2026 tutorial: "Contributing to Stan: A Developer’s Guide to the Core, Interfaces, and First Contributions" to be followed later by @brianward.dev and @bronder.deals 1231
MC Stan @mc-stan.org · 11/08/2026Call for StanCon 2027+ If you think you would like to organize the next StanCon (after Uppsala), click the link and read more! discourse.mc-stan.org/t/call-for-s...discourse.mc-stan.orgCall for StanCon 2027+We are looking for volunteers to organize the next StanCons for 2027 (and beyond!) If you are interested in making a proposal (or even just discussing the possibility of making one), please consider ... 032
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 06/08/2026Final day to register for StanCon 2026: 10th of August! Looking forward to a great conference! discourse.mc-stan.org/t/final-day-...discourse.mc-stan.orgFinal day to register for StanCon 2026 the 10th of August (AoE)Hi all! Also, the 10th of August (AoE) is the final deadline to register for StanCon 2026. After that we will need to set the final participation list for the practicalities of the conference. The p... 153
Reposted by MC StanMatthijs Hollanders @matthollanders.bsky.social · 01/07/2026Turns out continuous time hidden Markov model-step selection functions (HMM-SSF) with unequal sampling intervals sample like a dream in @mc-stan.org🔥 192
Reposted by MC StanSam Abbott @seabbs.bsky.social · 30/06/2026Great to see {epidist} and so @paulbuerkner.com {brms} and @mc-stan.org getting used as part of the reporting of the clinical characteristics of the Bundibugyo Virus outbreak in the DRC. 153
Reposted by MC StanMatti Vihola @mattivihola.bsky.social · 18/06/2026Our paper (with Alain Durmus, Samuel Gruffaz, Miika Kailas and Eero Saksman) on the ergodicity of dynamic path length HMC algorithms appeared in the AAP: doi.org/10.1214/25-A.... The results accommodate the 'biased progressive sampling' path selection used in @mc-stan.org.doi.org 184
Reposted by MC StanRich Ramsey @richramseyphd.bsky.social · 11/06/2026Have you ever tried to combine Positron, renv, brms/CmdStan, Quarto, and Docker into a reproducible scientific workflow in R? I didn't think so. Here is my attempt. #openscience #rstats #positron inspired by: @andrew.heiss.phd @matti.vuorre.com @mc-stan.org github.com/rich-ramsey/...github.comGitHub - rich-ramsey/positron-workflow: This project presents a minimal reproducible workflow template for cognitive neuroscience research using Positron, R, Bayesian modelling, and Docker.This project presents a minimal reproducible workflow template for cognitive neuroscience research using Positron, R, Bayesian modelling, and Docker. - rich-ramsey/positron-workflow 0195
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 10/06/2026🔥 StanCon 2026 Early Bird deadline today (AoE) 🔥 discourse.mc-stan.org/t/stancon-20...discourse.mc-stan.orgStanCon 2026 deadline today! (AoE)Hi all, Today is the last day to register for StanCon 2026 at the early-bird rate and order the StanCon 2026 t-shirt. We hope to see you all in Uppsala from the 17th to the 21st of August! More info... 102
Reposted by MC StanAki Vehtari @avehtari.bsky.social · 03/06/2026Having seen the submitted talks and posters, StanCon 2026 is going to be awesome! 0154
Reposted by MC StanarXiv stat.CO Computation @statco-bot.bsky.social · 09/06/2026Trevor Campbell, Jonathan H. Huggins, Kyurae Kim, Charles C. Margossian: Large-scale empirical tuning and comparison of default optimizers for variational inference arxiv.org/abs/2606.07841 arxiv.org/pdf/2606.07841 arxiv.org/html/2606.07841 042
Reposted by MC StanAki Vehtari @avehtari.bsky.social · 08/06/2026Two recommendations for cmdstanr in case studies: 1) use sample(..., refresh=0) to avoid 80 lines of MCMC progress reporting 2) cmdstanr::print_stan_file() in Quarto with output asis to get color formatting ``` #| output: asis print_stan_file(stan_file) ``` e.g., avehtari.github.io/Bayesian-Wor... 1346
MC Stan @mc-stan.org · 05/06/20263) Contributing to Stan: A Developer’s Guide to the Core, Interfaces, and First Contributions: Would you like to contribute a new feature to Stan, or make your first contribution to the Stan ecosystem? By @avehtari.bsky.social, @brianward.dev, @florencebockting.bsky.social, @bronder.deals 040
MC Stan @mc-stan.org · 05/06/20262) Bayesian model diagnostics: Workflows and software tools: emphasizing the iterative nature of model building, fitting, evaluation, and critique. R packages posterior, bayesplot, and priorsense, and the Python package ArviZ. By @aloctavodia.bsky.social, @teemusailynoja.bsky.social, Noa Kallioinen 150
MC Stan @mc-stan.org · 05/06/2026StanCon tutorials: 1) Full-day introduction to applied Bayesian statistics with Stan: fundamentals of Bayesian inference and the Bayesian workflow, Stan ecosystem by Mitzi Morrisstancon2026.orgTutorials – Stan Conference 2026 140
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 03/06/2026🔥 The early-bird deadline for StanCon 2026 (and, even more importantly, the StanCon Uppsala T-shirt) is in one week! 🔥 More information can be found here: discourse.mc-stan.org/t/stancon-20...discourse.mc-stan.orgStanCon 2026: Early bird (and t-shirt) deadline in one week!Hi all! Also, the 10th of June (AoE) is the early-bird deadline, and after that, the conference fee will increase! Also, only those who register before the 10th of June will be able to buy a StanCon ... 174
MC Stan @mc-stan.org · 19/05/2026CmdStan 2.39 has been released! - embedded Laplace approximation - new yule_simon distribution - gamma_lccdf more stable - optimization convergence status in output - length-1 tuples See more at blog.mc-stan.org/2026/05/19/r... 0143
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 19/05/2026🔥 StanCon poster deadline and early bird deadline is coming up 🔥 discourse.mc-stan.org/t/stancon-20... @mc-stan.org @avehtari.bsky.socialdiscourse.mc-stan.orgStancon 2026: Poster presentation deadline the 27th of May and Early Bird the 10th of JuneHi all! Just a reminder that the last program deadline for StanCon is coming up. The 27th of May is the last deadline for poster presentations. Also, the 10th of June is the early-bird deadline, and... 022
Reposted by MC StanAki Vehtari @avehtari.bsky.social · 13/05/2026In "Uncertainty in Bayesian leave-one-out cross-validation based model comparison" doi.org/10.1214/25-B... we showed when LOO-CV elpd_diff and se_diff normal approximation uncertainty quantification in model comparison is well calibrated. We have now merged a related PR to loo R package 1/ 14110
Reposted by MC StanCristi Proistosescu @cristiproist.bsky.social · 12/05/2026Have you ever read the Sherwood, Webb et al 2020 assessment of ECS and thought "I'd love to play with the numbers if only it didn't take 1 day to sample the posterior?" Rejoice! I've implemented the model in @mc-stan.org, and it now runs in ~1 minute. You can even run it in Google colab: 1/cdds-uiuc.github.ioSherwood Webb 2020 in Stan — Google Colab edition - Climate Dynamics and Data Science Notes 2205
MC Stan @mc-stan.org · 04/05/2026If you have benefited from Stan, you can contribute back to the project also by nominating yourself to be part of Stan Governing Body (you don't need to be a developer) discourse.mc-stan.org/t/elections-...discourse.mc-stan.orgElections for Stan Governing Body 2026We’re renewing the Stan Governing Body (SGB) with 2 seats up for grabs (I’m continuing my 2-year term). Current SGB members may still run, however they are not guaranteed to preserve their seats. As i... 023
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 30/04/2026🔥 Announcing the last tutorial on Stancon 2026 🔥 discourse.mc-stan.org/t/announcing...discourse.mc-stan.orgAnnouncing the last tutorial of StanCon 2026We are happy to announce the last workshop at StanCon 2026 in August! Contributing to Stan: A Developer’s Guide to the Core, Interfaces, and First Contributions Would you like to contribute a new fe... 113
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 27/04/2026🔥 Announcing StanCon 2026 Program 🔥 Now we have a program for StanCon 2026 in Uppsala in August 17-21! discourse.mc-stan.org/t/announcing...discourse.mc-stan.orgAnnouncing the program for StanCon 2026!Hi everybody! Now we have a program for StanCon 2026! We have a lot of excellent contributed talks, tutorials, workshops, and keynotes. The full program can be found here: The program may still be... 196
Reposted by MC StanRiccardo Fusaroli @fusaroli.eurosky.social · 24/04/2026very early draft of the techniques we show-cased in class: fusaroli.github.io/AdvancedCogn...fusaroli.github.ioAppendix B — Stan Optimization Cheatsheet – Advanced Cognitive Modeling Notes 1152
Reposted by MC StanMagnus Johansson @pgmj.bsky.social · 23/04/2026I've made an R package for Bayesian Rasch #psychometrics with brms models, easyRaschBayes (on CRAN), implementing simple functions to create figures and tables with model fit metrics, etc. Attaching figures from conditional item infit, item-restscore with GK gamma, and the log-likelihood criterion. 24616
Reposted by MC StanMichael Flynn @flynnpolsci.bsky.social · 13/04/2026Finally finished up a blog post on estimating Bradley–Terry models using brms. www.m-flynn.com/posts/2025-1...m-flynn.com 01610
Reposted by MC StanMåns Magnusson @mansmag.bsky.social · 20/04/2026🔥 We’re pleased to announce two confirmed tutorials for #StanCon2026 🔥 _An introduction to applied Bayesian statistics with Stan_ — Mitzi Morris _Bayesian model diagnostics: Workflows and software tools_ — Osvaldo Martin, Teemu Säilynoja, and Noa Kallioinen More info: stancon2026.org/tutorials/stancon2026.orgTutorials – Stan Conference 2026 063
Reposted by MC StanArviZ @arviz.bsky.social · 20/03/2026New paper out in JOSS: “ArviZ: a modular and flexible library for exploratory analysis of Bayesian models” It covers the design principles behind ArviZ and the motivation for the refactoring in 1.0. joss.theoj.org/papers/10.21...joss.theoj.orgArviZ: a modular and flexible library for exploratory analysis of Bayesian modelsMartin et al., (2026). ArviZ: a modular and flexible library for exploratory analysis of Bayesian models. Journal of Open Source Software, 11(119), 9889, https://doi.org/10.21105/joss.09889 0136
Reposted by MC StanArviZ @arviz.bsky.social · 01/04/2026ArviZ 1.0 brings a lot of new plotting functionality. Check our gallery for a glimpse of what's new: python.arviz.org/projects/plo...python.arviz.orgExample gallery — arviz-plots dev documentation 195
Reposted by MC StanArviZ @arviz.bsky.social · 07/04/2026ArviZ now has built-in tools for prior & likelihood sensitivity analysis via power-scaling! Instead of fitting multiple models with different priors, you fit once and use importance sampling to approximate the effect of perturbing the prior or likelihood. 1167
Reposted by MC StanRiccardo Fusaroli @fusaroli.eurosky.social · 08/04/2026First tentative draft of huge chapter on bayesian models of cognition for my Cognitive Modeling (in @mc-stan.org )course notes: fusaroli.github.io/AdvancedCogn... I'll probably need to split it, as I want to add models of sequential update and empirical data 😅fusaroli.github.ioChapter 10 Bayesian Models of Cognition | Advanced Cognitive Modeling NotesMy notes for the advanced cognitive modeling course - 2026 3312
Reposted by MC StanMatthijs Hollanders @matthollanders.bsky.social · 14/04/2026occARU: Bayesian (multispecies) occupancy models for ARU data using @mc-stan.org. Automated recording units (ARUs) like camera traps produce rich time series which warrant going beyond occupancy and focusing on detection rates. 1/n mhollanders.github.io/occARU/mhollanders.github.ioOccupancy Models for Automated Recording Unit (ARU) DataBayesian (multispecies) occupancy models for ARU data using Stan. 184
Reposted by MC StanRiccardo Fusaroli @fusaroli.eurosky.social · 21/03/2026New Cognitive Modeling in R and @mc-stan.org chapters up: hierarchical modeling and model comparison. Still not satisfied with the text, but I brought the code and concepts up to date (LOO-PIT even, altho' still an info dump). Comments are welcome! fusaroli.github.io/AdvancedCogn...fusaroli.github.ioChapter 7 Individual Differences in Cognitive Strategies: The Hierarchical Architecture | 09 — Bayesian Models of CognitionMy notes for the advanced cognitive modeling course - 2026 2202