tidytext
Finished, widely taught, and shipping roxygen fixes.
Comparison · Analytics
cmdstanr vs loo
A side-by-side editorial comparison of cmdstanr and loo — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:stan
cmdstanr vs loo: at a glance
What is cmdstanr?
cmdstanr keeps adding fast approximations beside full HMC, and fighting Windows toolchains.
cmdstanr is the lightweight R interface to CmdStan, shelling out to the Stan binary rather than embedding it. The visible releases pair inference-method expansion, with laplace and pathfinder arriving in 0.7.0, against a continuous effort to make installation work on Windows. The most recent releases are dominated by CmdStan version compatibility and numerical fixes in the loo path.
What is loo?
loo keeps rewriting the diagnostics Bayesian modellers read off model comparison
loo computes leave-one-out cross-validation and model comparison for Bayesian models in the Stan ecosystem. Two releases in this window changed what users actually read: 2.7.0 replaced the fixed Pareto-k thresholds with sample-size-dependent ones and dropped the middle category, and 2.10.0 reshaped loo_compare's output into a data.frame with new uncertainty columns. The releases between are diagnostic robustness fixes and moment-matching corrections.
cmdstanr vs loo: editorial side-by-side
cmdstanr
0.0ANALYTICS
cmdstanr keeps adding fast approximations beside full HMC, and fighting Windows toolchains.
◆ Current state
cmdstanr is the lightweight R interface to CmdStan, shelling out to the Stan binary rather than embedding it. The visible releases pair inference-method expansion, with laplace and pathfinder arriving in 0.7.0, against a continuous effort to make installation work on Windows. The most recent releases are dominated by CmdStan version compatibility and numerical fixes in the loo path.
◆ Where it's heading
The package tracks CmdStan closely, and its own work concentrates in two places. One is broadening the method surface so approximate inference sits beside sampling on the same object, extended in 0.8.0 by letting a completed fit supply initial values for the next run. The other is cutting installation friction, which reaches its conclusion in 0.9.0 with RTools45 supported and no additional toolchain setup needed on Windows. Dependency trimming, such as dropping RcppEigen for direct Eigen interop, runs alongside both.
◆ Prediction
The cadence is a CmdStan release followed by a compatibility release here, so expect the next to track a newer CmdStan and continue the effective-sample-size numerical work in the loo method.
loo
2.5ANALYTICS
loo keeps rewriting the diagnostics Bayesian modellers read off model comparison
◆ Current state
loo computes leave-one-out cross-validation and model comparison for Bayesian models in the Stan ecosystem. Two releases in this window changed what users actually read: 2.7.0 replaced the fixed Pareto-k thresholds with sample-size-dependent ones and dropped the middle category, and 2.10.0 reshaped loo_compare's output into a data.frame with new uncertainty columns. The releases between are diagnostic robustness fixes and moment-matching corrections.
◆ Where it's heading
The package is being brought in line with the current PSIS literature rather than extended with new features, and the practical effect is that the numbers practitioners quote in papers keep changing meaning. Work is increasingly delegated to posterior for shared computations, and the project has added contributor process, benchmarks and a published AI contribution policy.
◆ Prediction
Expect further work on comparison diagnostics — the p_worse and diag_* columns are new enough that their defaults and documentation will likely be revised next.
Alternatives to cmdstanr and loo
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 cmdstanr or loo.
textrecipes
Text features finally stay sparse all the way to the model.
probably
The package that made calibration a step instead of an afterthought.
workflowsets
workflowsets keeps widening what counts as a model worth comparing.
workflows
The tidymodels pipeline grew a third stage, and it happens after the model runs.
vetiver
Posit's MLOps package went quiet for two years, then came back to keep up with recipes.
See all cmdstanr alternatives → · See all loo alternatives →
Recent activity from cmdstanr and loo
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 20d agoloopsis_smooth_tail revert and simplify arg restored
- 1mo agolooloo_compare returns a data.frame with new uncertainty columns ⚡
- 4mo agocmdstanrRTools45 support; Windows needs no extra toolchain setup
- 4mo agocmdstanrBugfix release: SUNDIALS linking, Windows paths, RTools
- 4mo agocmdstanrCmdStanFit objects usable as initial values; RcppEigen dropped
- 7mo agolooStacking overflow fixes and posterior-based ESS
- 2y agolooMore robust Pareto-k diagnostics and moment matching
- 2y agolooPareto-k thresholds now depend on sample size ⚡
- 2y agocmdstanrBugfix release with dedicated hpp generation step
- 2y agocmdstanrLaplace and Pathfinder inference methods added ⚡
- 2y agocmdstanrjacobian argument enabled for optimization; assorted fixes
- 3y agolooLOO predictive metrics and CRPS scoring functions
Frequently asked questions
What is the difference between cmdstanr and loo?
Both compete on the same themes — stan — within Analytics. loo is currently shipping more aggressively (velocity 2.5 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is cmdstanr better than loo?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. loo is currently shipping more aggressively (velocity 2.5 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.
What are the best alternatives to cmdstanr?
Top cmdstanr alternatives in Analytics are ranked by recent ship velocity. Browse the "cmdstanr alternatives" section above for the current picks, or visit /alternatives/cmdstanr for the full list with editorial commentary on each.
What are the best alternatives to loo?
Top loo alternatives in Analytics are ranked by recent ship velocity. Browse the "loo alternatives" section above for the current picks, or visit /alternatives/loo for the full list with editorial commentary on each.