# Latest

**URL:** https://discourse.mc-stan.org/latest.md

[Latest](https://discourse.mc-stan.org/latest.md) · [Categories](https://discourse.mc-stan.org/categories.md) · [Tags](https://discourse.mc-stan.org/tags.md)

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## [Welcome to the Stan Forums!](https://discourse.mc-stan.org/t/welcome-to-the-stan-forums/8)

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**Author:** [@system](https://discourse.mc-stan.org/u/system)\
**Replies:** 0\
**Last updated:** [August 6, 2016, 3:26pm UTC](https://discourse.mc-stan.org/t/welcome-to-the-stan-forums/8 "2016-08-06T15:26:23Z")

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The Stan Forums provide a community for asking and answering questions about all aspects of Stan. Before creating a new topic please search the Forums to see if your questions has already been answered. When posting ne…

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## [Seeking Independent Statistical Reviewer for Bayesian Ordinal Mixed-Effects Model (Pre-Submission Methodology Review)](https://discourse.mc-stan.org/t/seeking-independent-statistical-reviewer-for-bayesian-ordinal-mixed-effects-model-pre-submission-methodology-review/41616)

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**Author:** [@muharrem\_furkan\_yuzbasi](https://discourse.mc-stan.org/u/muharrem_furkan_yuzbasi)\
**Replies:** 2\
**Last updated:** [September 25, 2026, 4:22pm UTC](https://discourse.mc-stan.org/t/seeking-independent-statistical-reviewer-for-bayesian-ordinal-mixed-effects-model-pre-submission-methodology-review/41616 "2026-09-25T16:22:33Z")

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Hi all, I’m looking for an independent statistician to review the methodology of a completed research protocol before ethics committee submission and journal review. This is a methodology review engagement, not a full a…

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## [SBC derived quantities with vector of parameters](https://discourse.mc-stan.org/t/sbc-derived-quantities-with-vector-of-parameters/41618)

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**Author:** [@jkbest2](https://discourse.mc-stan.org/u/jkbest2)\
**Replies:** 2\
**Last updated:** [September 25, 2026, 7:29am UTC](https://discourse.mc-stan.org/t/sbc-derived-quantities-with-vector-of-parameters/41618 "2026-09-25T07:29:52Z")

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I’d like to include a derived quantity in my SBC run that uses a parameter vector as input. The simple version of the function takes the vector log\_lambda as its argument: tot\_abund \<- function(log\_lambda) { sum(rpois…

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## [Research Consultant (Modeling and Quant) - Remote - PT/FT](https://discourse.mc-stan.org/t/research-consultant-modeling-and-quant-remote-pt-ft/41628)

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**Author:** [@christina.filipovic](https://discourse.mc-stan.org/u/christina.filipovic)\
**Replies:** 0\
**Last updated:** [September 24, 2026, 9:37pm UTC](https://discourse.mc-stan.org/t/research-consultant-modeling-and-quant-remote-pt-ft/41628 "2026-09-24T21:37:23Z")

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Unit: Digital Planet, The Fletcher School, Tufts University Reports to: Head of Research Hours: Part-time (20 hours) and full-time (35 hours), hourly available. Rate: $30-$50, DOE Duration: Immediate start throug…

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## [Call for Papers: Advanced Geographic Data Science and Modelling for Vector-Borne Diseases and NTDs](https://discourse.mc-stan.org/t/call-for-papers-advanced-geographic-data-science-and-modelling-for-vector-borne-diseases-and-ntds/41586)

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**Author:** [@UCLPG-MSC-SGDS](https://discourse.mc-stan.org/u/UCLPG-MSC-SGDS)\
**Replies:** 7\
**Last updated:** [September 23, 2026, 6:13pm UTC](https://discourse.mc-stan.org/t/call-for-papers-advanced-geographic-data-science-and-modelling-for-vector-borne-diseases-and-ntds/41586 "2026-09-23T18:13:32Z")

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Dear all, I hope this message finds you well. I just want to take this opportunity to share news on this platform about our Special Issue with those working with Bayesian models applied to vector-borne diseases (or neg…

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## [Submission: Case study on probabilistic knowledge structures](https://discourse.mc-stan.org/t/submission-case-study-on-probabilistic-knowledge-structures/41611)

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**Author:** [@Florian\_Wickelmaier](https://discourse.mc-stan.org/u/Florian_Wickelmaier)\
**Replies:** 4\
**Last updated:** [September 23, 2026, 8:02am UTC](https://discourse.mc-stan.org/t/submission-case-study-on-probabilistic-knowledge-structures/41611 "2026-09-23T08:02:39Z")

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I would like to submit a case study on probabilistic knowledge structures: Knowledge structure theory is a field in psychometrics that seeks to provide procedures for the effective diagnosis of the knowledge state of…

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## [Province-Level Clustered Standard Errors in MRP](https://discourse.mc-stan.org/t/province-level-clustered-standard-errors-in-mrp/41610)

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**Author:** [@yanmin](https://discourse.mc-stan.org/u/yanmin)\
**Replies:** 3\
**Last updated:** [September 23, 2026, 2:27am UTC](https://discourse.mc-stan.org/t/province-level-clustered-standard-errors-in-mrp/41610 "2026-09-23T02:27:56Z")

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I conducted a study using Multilevel Regression and Poststratification (MRP). One reviewer raised the following concern: “Following Abadie et al. (2023), if the authors insist on conducting the analysis at the province …

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## [Priors for circular distributions, and models for circular targets and covariates](https://discourse.mc-stan.org/t/priors-for-circular-distributions-and-models-for-circular-targets-and-covariates/41575)

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**Author:** [@avehtari](https://discourse.mc-stan.org/u/avehtari)\
**Replies:** 6\
**Last updated:** [September 22, 2026, 8:06pm UTC](https://discourse.mc-stan.org/t/priors-for-circular-distributions-and-models-for-circular-targets-and-covariates/41575 "2026-09-22T20:06:30Z")

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@Xiang\_Ye has worked on circular distributions initially for INLA, but as he was visiting at Aalto, he started making three Stan case studies that are now available and I think they are great and worth checking out by an…

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## [Stan, stanr, and brms running client-side in the browser via webR](https://discourse.mc-stan.org/t/stan-stanr-and-brms-running-client-side-in-the-browser-via-webr/41549)

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**Author:** [@StaffanBetner](https://discourse.mc-stan.org/u/StaffanBetner)\
**Replies:** 6\
**Last updated:** [September 22, 2026, 7:57am UTC](https://discourse.mc-stan.org/t/stan-stanr-and-brms-running-client-side-in-the-browser-via-webr/41549 "2026-09-22T07:57:42Z")

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Hi all, I’ve been experimenting with running Stan inside webR and wanted to share a working proof-of-concept. Thanks to @seantalts’ work on stanli (the Stan interpreter/runtime) and @andrjohns’ work on stanr and his st…

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## [Comparing stan backend to Julia / native cpp (ctsem, continuous time nonlinear state space modelling)](https://discourse.mc-stan.org/t/comparing-stan-backend-to-julia-native-cpp-ctsem-continuous-time-nonlinear-state-space-modelling/41545)

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**Author:** [@Charles\_Driver](https://discourse.mc-stan.org/u/Charles_Driver)\
**Replies:** 16\
**Last updated:** [September 22, 2026, 7:31am UTC](https://discourse.mc-stan.org/t/comparing-stan-backend-to-julia-native-cpp-ctsem-continuous-time-nonlinear-state-space-modelling/41545 "2026-09-22T07:31:53Z")

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Just thought it might interest some here – I’m migrating the ctsem software GitHub - cdriveraus/ctsem: Hierarchical continuous time state space modelling · GitHub (now with GUI for anyone really curious! GitHub - cdriver…

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## [Dependence between binary responses in multivariate brms](https://discourse.mc-stan.org/t/dependence-between-binary-responses-in-multivariate-brms/41608)

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**Author:** [@JKingston](https://discourse.mc-stan.org/u/JKingston)\
**Replies:** 5\
**Last updated:** [September 20, 2026, 8:49pm UTC](https://discourse.mc-stan.org/t/dependence-between-binary-responses-in-multivariate-brms/41608 "2026-09-20T20:49:11Z")

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I have data in which participants chose between 4 possible responses on each trial. The 4 responses are best understood, however, as two binary choices, i.e., “w” vs “b” and “2” vs “1”. What I want to get from the model …

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## [Release of CmdStan 2.40.0](https://discourse.mc-stan.org/t/release-of-cmdstan-2-40-0/41606)

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**Author:** [@WardBrian](https://discourse.mc-stan.org/u/WardBrian)\
**Replies:** 8\
**Last updated:** [September 18, 2026, 2:34pm UTC](https://discourse.mc-stan.org/t/release-of-cmdstan-2-40-0/41606 "2026-09-18T14:34:10Z")

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We are very happy to announce that CmdStan 2.40.0 is out! This release cycle brings new 1-D integration functions, quality of life improvements, and many bug fixes. For details, see the blog post: Release of CmdStan 2.…

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## [Help testing brms pr for sum-to-zero and partial centering](https://discourse.mc-stan.org/t/help-testing-brms-pr-for-sum-to-zero-and-partial-centering/41542)

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**Author:** [@spinkney](https://discourse.mc-stan.org/u/spinkney)\
**Replies:** 43\
**Last updated:** [September 18, 2026, 9:39am UTC](https://discourse.mc-stan.org/t/help-testing-brms-pr-for-sum-to-zero-and-partial-centering/41542 "2026-09-18T09:39:05Z")

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Hi brms users, I’m hoping to get eyes on this pr Add fast sum-to-zero parameterizations for group effects by spinkney · Pull Request #1919 · paul-buerkner/brms · GitHub Warnings, it is large and it is AI generated becau…

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## [On LOO CV for non-factorizable normal models](https://discourse.mc-stan.org/t/on-loo-cv-for-non-factorizable-normal-models/7336)

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**Author:** [@Elizaveta\_Semenova](https://discourse.mc-stan.org/u/Elizaveta_Semenova)\
**Replies:** 2\
**Last updated:** [September 17, 2026, 8:39pm UTC](https://discourse.mc-stan.org/t/on-loo-cv-for-non-factorizable-normal-models/7336 "2026-09-17T20:39:45Z")

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Dear all, I have a question concerning LOO-CV for non-factorisable normal models, developed in the paper “Leave-one-out cross-validation for non-factorizable normal models” by Bürkner, Gabry, Vehtari. The idea of the pa…

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## [How to handle divergent chains in Stan mixture models](https://discourse.mc-stan.org/t/how-to-handle-divergent-chains-in-stan-mixture-models/41598)

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**Author:** [@digikar](https://discourse.mc-stan.org/u/digikar)\
**Replies:** 3\
**Last updated:** [September 17, 2026, 2:52pm UTC](https://discourse.mc-stan.org/t/how-to-handle-divergent-chains-in-stan-mixture-models/41598 "2026-09-17T14:52:24Z")

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Hello, I want to use a mixture model to decide whether my data is better explained by two components or by a single component. For example, let me take (simulated) data to be the following. The model behaves well (Reff …

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## [Can some individual-level predictors included in the regression model be excluded from the poststratification frame?](https://discourse.mc-stan.org/t/can-some-individual-level-predictors-included-in-the-regression-model-be-excluded-from-the-poststratification-frame/41592)

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**Author:** [@yanmin](https://discourse.mc-stan.org/u/yanmin)\
**Replies:** 2\
**Last updated:** [September 17, 2026, 1:37am UTC](https://discourse.mc-stan.org/t/can-some-individual-level-predictors-included-in-the-regression-model-be-excluded-from-the-poststratification-frame/41592 "2026-09-17T01:37:05Z")

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In multilevel regression and poststratification (MRP), do all individual-level predictors included in the regression model need to be available in the poststratification frame? For example, if the poststratification fram…

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## [Sum-to-zero with a covariance matrix](https://discourse.mc-stan.org/t/sum-to-zero-with-a-covariance-matrix/41558)

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**Author:** [@mhollanders](https://discourse.mc-stan.org/u/mhollanders)\
**Replies:** 8\
**Last updated:** [September 15, 2026, 9:52pm UTC](https://discourse.mc-stan.org/t/sum-to-zero-with-a-covariance-matrix/41558 "2026-09-15T21:52:22Z")

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Hi all, Given the surge of posts about sum-to-zero recently I thought I’d add another one. I’ve posted about this on Slack before but it might be of broader interest. My question is about implementing sum-to-zero vecto…

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## [Setting up Emacs for Stan in 2026](https://discourse.mc-stan.org/t/setting-up-emacs-for-stan-in-2026/40970)

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**Author:** [@WardBrian](https://discourse.mc-stan.org/u/WardBrian)\
**Replies:** 10\
**Last updated:** [September 15, 2026, 4:57pm UTC](https://discourse.mc-stan.org/t/setting-up-emacs-for-stan-in-2026/40970 "2026-09-15T16:57:09Z")

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It is easier than ever to set up Emacs for Stan development. Here’s a screen shot of the kind of thing you can expect: The entire init.el needed to get this behavior is below (excluding the theme, which is zenburn). …

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## [Baseball Analytics Opportunities with the Washington Nationals ](https://discourse.mc-stan.org/t/baseball-analytics-opportunities-with-the-washington-nationals/41602)

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**Author:** [@dmcgowan](https://discourse.mc-stan.org/u/dmcgowan)\
**Replies:** 0\
**Last updated:** [September 15, 2026, 8:16am UTC](https://discourse.mc-stan.org/t/baseball-analytics-opportunities-with-the-washington-nationals/41602 "2026-09-15T08:16:18Z")

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We’re looking for two Senior Analysts in our Player Projections group who can help us take our modeling efforts to the next level. One of these new hires will focus on Amateur player projections and the other will focus …

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## [Opportunity for students in Prague](https://discourse.mc-stan.org/t/opportunity-for-students-in-prague/41596)

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**Author:** [@martinmodrak](https://discourse.mc-stan.org/u/martinmodrak)\
**Replies:** 0\
**Last updated:** [September 14, 2026, 12:17pm UTC](https://discourse.mc-stan.org/t/opportunity-for-students-in-prague/41596 "2026-09-14T12:17:39Z")

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Hi, I will be hiring for a grant supported PhD student (primarily) position in Prague, to work with me in collaboration with @paul.buerkner’s group on grammo - a grammar of models. The short pitch is that we want to bui…

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## [CmdStan & Stan 2.40 Release Candidates](https://discourse.mc-stan.org/t/cmdstan-stan-2-40-release-candidates/41585)

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**Author:** [@WardBrian](https://discourse.mc-stan.org/u/WardBrian)\
**Replies:** 11\
**Last updated:** [September 12, 2026, 10:21pm UTC](https://discourse.mc-stan.org/t/cmdstan-stan-2-40-release-candidates/41585 "2026-09-12T22:21:32Z")

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I am happy to announce that the latest release candidates of CmdStan and Stan are now available on Github! You can find the release candidate for CmdStan here. Instructions for installing are given at the bottom of this…

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## [RStan compilation error with R 4.6.1, Rtools45 and rstan 2.39](https://discourse.mc-stan.org/t/rstan-compilation-error-with-r-4-6-1-rtools45-and-rstan-2-39/41589)

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**Author:** [@Marta](https://discourse.mc-stan.org/u/Marta)\
**Replies:** 4\
**Last updated:** [September 12, 2026, 9:07am UTC](https://discourse.mc-stan.org/t/rstan-compilation-error-with-r-4-6-1-rtools45-and-rstan-2-39/41589 "2026-09-12T09:07:05Z")

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Hello, I am having a compilation problem with RStan on Windows and would appreciate your help identifying the cause. My current setup is: Windows 10 Pro R 4.6.1 (2026-06-24 ucrt) Rtools45 GCC 14.3.0 rsta…

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## [Mixis and E\_loo](https://discourse.mc-stan.org/t/mixis-and-e-loo/40602)

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**Author:** [@gregd](https://discourse.mc-stan.org/u/gregd)\
**Replies:** 25\
**Last updated:** [September 9, 2026, 11:41am UTC](https://discourse.mc-stan.org/t/mixis-and-e-loo/40602 "2026-09-09T11:41:58Z")

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hello E\_loo uses the weights generated by loo to estimate the leave-one-out mean (and quantiles). However, “A small Pareto k estimate is necessary, but not sufficient, for E\_loo() to give reliable estimates.” Mixis is m…

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## [Stanwasm: a browser-first Stan subset with per-model wasm codegen — looking for feedbackd](https://discourse.mc-stan.org/t/stanwasm-a-browser-first-stan-subset-with-per-model-wasm-codegen-looking-for-feedbackd/41568)

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**Author:** [@habakan](https://discourse.mc-stan.org/u/habakan)\
**Replies:** 4\
**Last updated:** [September 9, 2026, 1:19am UTC](https://discourse.mc-stan.org/t/stanwasm-a-browser-first-stan-subset-with-per-model-wasm-codegen-looking-for-feedbackd/41568 "2026-09-09T01:19:31Z")

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I’ve been independently building stanwasm, an implementation of a subset of the Stan language that parses, compiles and samples models entirely in the browser. It is an independent implementation rather than a port: it…

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## [Planning the 2.40 release](https://discourse.mc-stan.org/t/planning-the-2-40-release/41502)

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**Author:** [@WardBrian](https://discourse.mc-stan.org/u/WardBrian)\
**Replies:** 7\
**Last updated:** [September 8, 2026, 8:56pm UTC](https://discourse.mc-stan.org/t/planning-the-2-40-release/41502 "2026-09-08T20:56:16Z")

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It’s that time again! We’re coming up on 4 months post-2.39 release (May 19th). I’d like to propose the following dates for the 2.40 release: Feature freeze on Tuesday, September 8th 2026 Release on Tuesday, September…

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## [Big Collection of Stan Ecosystem PRs](https://discourse.mc-stan.org/t/big-collection-of-stan-ecosystem-prs/41544)

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**Author:** [@scholz](https://discourse.mc-stan.org/u/scholz)\
**Replies:** 11\
**Last updated:** [September 8, 2026, 8:40pm UTC](https://discourse.mc-stan.org/t/big-collection-of-stan-ecosystem-prs/41544 "2026-09-08T20:40:40Z")

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Bob made me do it! After watching the walnutpie video by @Bob\_Carpenter I decided to spend some time with walnutpie. When I first saw it announced on Andrew’s Blog I commented that trying out muon as an alternative to a…

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## [Keep getting infinite gradient although likelihood is differentiable](https://discourse.mc-stan.org/t/keep-getting-infinite-gradient-although-likelihood-is-differentiable/41541)

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**Author:** [@SeHellmann](https://discourse.mc-stan.org/u/SeHellmann)\
**Replies:** 8\
**Last updated:** [September 8, 2026, 8:28pm UTC](https://discourse.mc-stan.org/t/keep-getting-infinite-gradient-although-likelihood-is-differentiable/41541 "2026-09-08T20:28:57Z")

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I am trying to fit a model to a couple (19) datasets. For 16 datasets, the model runs smoothly (no divergences, reasonable Rhat, and very good ESSs). But it seems, three datasets are a bit hard to estimate. I determined …

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## [Postdoc and doctoral student positions in Bayesian workflow at Aalto, Finland](https://discourse.mc-stan.org/t/postdoc-and-doctoral-student-positions-in-bayesian-workflow-at-aalto-finland/41555)

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**Author:** [@avehtari](https://discourse.mc-stan.org/u/avehtari)\
**Replies:** 2\
**Last updated:** [September 8, 2026, 8:20pm UTC](https://discourse.mc-stan.org/t/postdoc-and-doctoral-student-positions-in-bayesian-workflow-at-aalto-finland/41555 "2026-09-08T20:20:15Z")

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I’m looking for postdocs and doctoral students to work on Bayesian workflow. The candidates need to have knowledge of Bayesian inference and some experience with building models (for real applications, as part of methods…

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## [How to specify non centered parameterization for sigma in a distributional model in brms](https://discourse.mc-stan.org/t/how-to-specify-non-centered-parameterization-for-sigma-in-a-distributional-model-in-brms/41570)

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**Author:** [@rstanuser](https://discourse.mc-stan.org/u/rstanuser)\
**Replies:** 8\
**Last updated:** [September 7, 2026, 11:13pm UTC](https://discourse.mc-stan.org/t/how-to-specify-non-centered-parameterization-for-sigma-in-a-distributional-model-in-brms/41570 "2026-09-07T23:13:28Z")

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I want to fit a distributional model with brms along the following lines: df \<- data.frame() # some columns include: # value (continuous, zero-mean), # afactor (3 levels), bfactor (7 levels), # gfactor (240 level…

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## [Discretizing a hurdle model in order to compare it to a gaussian model: Part 2](https://discourse.mc-stan.org/t/discretizing-a-hurdle-model-in-order-to-compare-it-to-a-gaussian-model-part-2/41562)

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**Author:** [@llewmills](https://discourse.mc-stan.org/u/llewmills)\
**Replies:** 4\
**Last updated:** [September 7, 2026, 9:31pm UTC](https://discourse.mc-stan.org/t/discretizing-a-hurdle-model-in-order-to-compare-it-to-a-gaussian-model-part-2/41562 "2026-09-07T21:31:40Z")

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In this post a few days ago I attempted to get some advice on the procedure for discretizing a hurdle model and a gaussian model of the same outcome data so as to compare the two (recommended by @avehtari in his reply he…

[Next page](https://discourse.mc-stan.org/latest.md?page=1)