← Back to home
Comparison · Analytics

posterior vs rstanarm

A side-by-side editorial comparison of posterior and rstanarm — release velocity, themes, recent moves, and the top alternatives to consider.

Shared themes:bayesian

posterior vs rstanarm: at a glance

Featureposteriorrstanarm
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themesbayesian, rvar, pareto-diagnostics, r-infrastructurebayesian, stan, regression-models, dependency-migration
Last editorial update1h ago1h ago
WebsiteVisit →Visit →

What is posterior?

posterior keeps deepening two things: the rvar type and Pareto-based diagnostics.

The releases in this window advance on two fronts. The rvar random-variable type gained factor and ordered subtypes (1.4.0), rvar-indexed slicing and `rvar_ifelse()` (1.5.0), base `%*%` matrix multiplication and indexed variable names (1.6.0). Separately, Pareto diagnostics have grown from `pareto_smooth()` options and individual `pareto_khat()`-family functions (1.6.0) through `pit()` for draws and rvars (1.6.1) to exported generalized-Pareto functions and `pareto_pit` (1.7.0). 1.7.1 is a paperwork release for a JOSS submission.

Read the full posterior trajectory →

What is rstanarm?

rstanarm is community-maintained now, tracking Stan and lme4 rather than adding models.

2.32.2 is entirely infrastructure and dependency work: formula machinery migrated from lme4 to reformulas, `r_eff` no longer computed for loo by default, the Stan R packages repo replaced by R-Universe, rstantools adopted to fix build and export errors, and CRAN NOTE cleanups — contributed largely by four first-time contributors. 2.32.1 and 2.26.1 follow the same pattern, tracking rstan syntax and adding `posterior::as_draws()` support. The last release with substantive modelling content is 2.21.1, which changed how default priors are determined and flipped `autoscale` to FALSE outside default priors.

Read the full rstanarm trajectory →

posterior vs rstanarm: editorial side-by-side

P
posterior
ANALYTICS
0.0

posterior keeps deepening two things: the rvar type and Pareto-based diagnostics.

◆ Current state

The releases in this window advance on two fronts. The rvar random-variable type gained factor and ordered subtypes (1.4.0), rvar-indexed slicing and `rvar_ifelse()` (1.5.0), base `%*%` matrix multiplication and indexed variable names (1.6.0). Separately, Pareto diagnostics have grown from `pareto_smooth()` options and individual `pareto_khat()`-family functions (1.6.0) through `pit()` for draws and rvars (1.6.1) to exported generalized-Pareto functions and `pareto_pit` (1.7.0). 1.7.1 is a paperwork release for a JOSS submission.

◆ Where it's heading

posterior is positioning itself as shared infrastructure rather than an end-user package: 1.7.0 explicitly exports generalized-Pareto machinery 'for use in other packages', and the JOSS paper is a citation vehicle for the same audience. The rvar work points the same way — a random-variable type other Bayesian packages can build on. Cadence is steady but unhurried, roughly one feature release a year.

◆ Prediction

More diagnostic functions are likely to be exported for downstream reuse, following the pattern 1.7.0 established with the generalized-Pareto helpers.

R
rstanarm
ANALYTICS
0.0

rstanarm is community-maintained now, tracking Stan and lme4 rather than adding models.

◆ Current state

2.32.2 is entirely infrastructure and dependency work: formula machinery migrated from lme4 to reformulas, `r_eff` no longer computed for loo by default, the Stan R packages repo replaced by R-Universe, rstantools adopted to fix build and export errors, and CRAN NOTE cleanups — contributed largely by four first-time contributors. 2.32.1 and 2.26.1 follow the same pattern, tracking rstan syntax and adding `posterior::as_draws()` support. The last release with substantive modelling content is 2.21.1, which changed how default priors are determined and flipped `autoscale` to FALSE outside default priors.

◆ Where it's heading

The package has moved from feature development into ecosystem maintenance, and the contributor list shows why it survives: outside developers keep it compiling against a moving Stan, lme4 and CRAN. The `as_draws()` support and the reformulas migration both point the same way — rstanarm increasingly consumes shared infrastructure (posterior, reformulas, rstantools) instead of carrying its own.

◆ Prediction

Expect the next release to track another upstream change — rstan, reformulas or CRAN policy — rather than add model families. The pre-fit model surface looks settled.

Alternatives to posterior and rstanarm

Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either posterior or rstanarm.

See all posterior alternatives → · See all rstanarm alternatives →

Recent activity from posterior and rstanarm

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 2mo agoposteriorposterior 1.7.1 released for JOSS paper
  2. 3mo agoposteriorposterior 1.7.0 exports generalized-Pareto functions
  3. 10mo agoposteriorposterior 1.6.1 adds pit() for draws and rvars
  4. 10mo agorstanarmrstanarm 2.32.2 migrates formula machinery to reformulas
  5. 1y agoposteriorposterior 1.6.0 adds Pareto diagnostics and ESS-based thinning
  6. 2y agorstanarmrstanarm 2.32.1 fixes unit_vector error, enables LTO
  7. 2y agoposteriorposterior 1.5.0 adds nested-Rhat and rvar indexing
  8. 2y agorstanarmrstanarm 2.26.1 adopts new rstan syntax and as_draws()
  9. 3y agoposteriorposterior 1.4.0 adds factor and ordered rvar subtypes
  10. 4y agorstanarmrstanarm 2.21.3 fixes loo() and adds stan_jm offsets
  11. 6y agorstanarmrstanarm 2.21.1 changes default prior behaviour

Frequently asked questions

What is the difference between posterior and rstanarm?

Both compete on the same themes — bayesian — within Analytics. posterior and rstanarm are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is posterior better than rstanarm?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. posterior and rstanarm are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to posterior?

Top posterior alternatives in Analytics are ranked by recent ship velocity. Browse the "posterior alternatives" section above for the current picks, or visit /alternatives/posterior for the full list with editorial commentary on each.

What are the best alternatives to rstanarm?

Top rstanarm alternatives in Analytics are ranked by recent ship velocity. Browse the "rstanarm alternatives" section above for the current picks, or visit /alternatives/rstanarm for the full list with editorial commentary on each.