Type: Package
Package: loo
Title: Efficient Leave-One-Out Cross-Validation and WAIC for Bayesian
        Models
Version: 2.9.0
Date: 2025-12-22
Authors@R: c(
    person("Aki", "Vehtari", email = "Aki.Vehtari@aalto.fi", role = "aut"),
    person("Jonah", "Gabry", email = "jgabry@gmail.com", role = c("cre", "aut")),
    person("Måns", "Magnusson", role = "aut"),
    person("Yuling", "Yao", role = "aut"),
    person("Paul-Christian", "Bürkner", role = "aut"),
    person("Topi", "Paananen", role = "aut"),
    person("Andrew", "Gelman", role = "aut"),
    person("Ben", "Goodrich", role = "ctb"),
    person("Juho", "Piironen", role = "ctb"),
    person("Bruno", "Nicenboim", role = "ctb"),
    person("Leevi", "Lindgren", role = "ctb"),
    person("Visruth", "Srimath Kandali", role = "ctb")
  )
Maintainer: Jonah Gabry <jgabry@gmail.com>
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.
License: GPL (>=3)
URL: https://mc-stan.org/loo/, https://discourse.mc-stan.org
BugReports: https://github.com/stan-dev/loo/issues
Depends: R (>= 3.1.2)
Imports: checkmate, matrixStats (>= 0.52), parallel, posterior (>=
        1.5.0), stats
Suggests: bayesplot (>= 1.7.0), brms (>= 2.10.0), ggplot2, graphics,
        knitr, rmarkdown, rstan, rstanarm (>= 2.19.0), rstantools,
        spdep, testthat (>= 3.0)
VignetteBuilder: knitr
Config/testthat/edition: 3
Config/testthat/parallel: true
Config/testthat/start-first: loo_subsampling_cases, loo_subsampling
Encoding: UTF-8
LazyData: TRUE
Roxygen: list(markdown = TRUE)
RoxygenNote: 7.3.3
SystemRequirements: pandoc (>= 1.12.3), pandoc-citeproc
Repository: https://r-multiverse-staging.r-universe.dev
Date/Publication: 2025-12-23 15:30:47 UTC
RemoteUrl: https://github.com/stan-dev/loo
RemoteRef: 299a4c7af159b08b3be0184744cc1a9615b6a341
RemoteSha: 299a4c7af159b08b3be0184744cc1a9615b6a341
NeedsCompilation: no
Packaged: 2026-06-20 06:59:10 UTC; root
Author: Aki Vehtari [aut],
  Jonah Gabry [cre, aut],
  Måns Magnusson [aut],
  Yuling Yao [aut],
  Paul-Christian Bürkner [aut],
  Topi Paananen [aut],
  Andrew Gelman [aut],
  Ben Goodrich [ctb],
  Juho Piironen [ctb],
  Bruno Nicenboim [ctb],
  Leevi Lindgren [ctb],
  Visruth Srimath Kandali [ctb]