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loo

Efficient Leave-One-Out Cross-Validation and WAIC for Bayesian Models

v2.9.0 · Dec 22, 2025 · GPL (>= 3)

Description

Efficient approximate leave-one-out cross-validation (LOO) for Bayesian models fit using Markov chain Monte Carlo, as described in Vehtari, Gelman, and Gabry (2017) <doi:10.1007/s11222-016-9696-4>. The approximation uses Pareto smoothed importance sampling (PSIS), a new procedure for regularizing importance weights. As a byproduct of the calculations, we also obtain approximate standard errors for estimated predictive errors and for the comparison of predictive errors between models. The package also provides methods for using stacking and other model weighting techniques to average Bayesian predictive distributions.

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Check History

OK 14 OK · 0 NOTE · 0 WARNING · 0 ERROR · 0 FAILURE Mar 9, 2026

Reverse Dependencies (87)

Dependency Network

Dependencies Reverse dependencies checkmate matrixStats posterior (>= 1.5.0) TriDimRegression bistablehistory evidence spsurv BAMBI BayesERtools BayesGrowth BayesianFitForecast CLRtools CRTspat EBcoBART FlexReg GPTCM HeckmanStan LMMELSM +72 more reverse deps loo

Version History

new 2.9.0 Mar 9, 2026