← Back to home
Comparison · Analytics

forecast vs loo

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

Shared themes:r-stats

forecast vs loo: at a glance

Featureforecastloo
SectorAnalyticsAnalytics
Velocity score0.02.5
Sparks · 30d00
Top themesforecasting, time-series, r-stats, major-releasebayesian, cross-validation, stan, r-stats
Last editorial update1h ago1h ago
WebsiteVisit →Visit →

What is forecast?

After years of pure maintenance, forecast 9.0.0 reopens the package

forecast is the long-established R forecasting package that fable was meant to succeed. For several years its releases were RNG fixes, base-R compatibility and documentation. Then 9.0.0 arrived with a batch of new model constructors, wider prediction-interval support and a rewritten accuracy() built on S3 methods.

Read the full forecast trajectory →

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.

Read the full loo trajectory →

forecast vs loo: editorial side-by-side

F
forecast
ANALYTICS
0.0

After years of pure maintenance, forecast 9.0.0 reopens the package

◆ Current state

forecast is the long-established R forecasting package that fable was meant to succeed. For several years its releases were RNG fixes, base-R compatibility and documentation. Then 9.0.0 arrived with a batch of new model constructors, wider prediction-interval support and a rewritten accuracy() built on S3 methods.

◆ Where it's heading

The major version reframes forecast around explicit *_model() constructors — mean, random walk, spline, theta, Croston — rather than the older function-per-method style, and the 9.0.x patches since have been performance and argument-handling cleanups on top. That is an active maintenance line, not a package winding down in favour of fable.

◆ Prediction

Expect continued 9.0.x patches consolidating the new constructors and their forecast methods, with the older interfaces kept working alongside them.

L
loo
ANALYTICS
2.5

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 forecast 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 forecast or loo.

See all forecast alternatives → · See all loo alternatives →

Recent activity from forecast and loo

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

  1. 20d agoloopsis_smooth_tail revert and simplify arg restored
  2. 1mo agolooloo_compare returns a data.frame with new uncertainty columns
  3. 4mo agoforecastFixes for checkresiduals() and mstl() lambda handling
  4. 5mo agoforecastFaster ARFIMA search and forecast.mlm() argument handling
  5. 7mo agoforecastforecast 9.0.0 adds five model constructors and rewrites accuracy()
  6. 7mo agolooStacking overflow fixes and posterior-based ESS
  7. 1y agoforecastDocumentation and bug-fix release
  8. 2y agolooMore robust Pareto-k diagnostics and moment matching
  9. 2y agoforecastRNG state and base-R head/tail compatibility
  10. 2y agoforecastMuch faster hfitted() for ARIMA and ETS models
  11. 2y agolooPareto-k thresholds now depend on sample size
  12. 3y agolooLOO predictive metrics and CRPS scoring functions

Frequently asked questions

What is the difference between forecast and loo?

Both compete on the same themes — r-stats — 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 forecast 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 forecast?

Top forecast alternatives in Analytics are ranked by recent ship velocity. Browse the "forecast alternatives" section above for the current picks, or visit /alternatives/forecast-r 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.