Generic function for drawing from the posterior predictive distribution

Description

Draw from the posterior predictive distribution of the outcome. See posterior_predict.stanreg in the rstanarm package for an example.

Usage

posterior_predict(object, ...)

Arguments

Value

posterior_predict methods should return a D by N matrix, where D is the number of draws from the posterior predictive distribution and N is the number of data points being predicted per draw.

See Also

• The rstanarm package for example methods (CRAN, GitHub).

• The guidelines for developers of R packages interfacing with Stan, a copy of which can be found in the package vignettes. See browseVignettes("rstantools") or vignette(package = "rstantools"). The document is also available online at the rstantools page on the CRAN website.

Examples

# Example using rstanarm package:
# posterior_predict method for 'stanreg' objects

if (require("rstanarm")) {
  fit <- stan_glm(mpg ~ wt + am, data = mtcars)
  yrep <- posterior_predict(fit)
  all.equal(ncol(yrep), nobs(fit))

  nd <- data.frame(wt = mean(mtcars$wt), am = c(0, 1))
  ytilde <- posterior_predict(fit, newdata = nd)
  all.equal(ncol(ytilde), nrow(nd))
}


# Also see help("posterior_predict", package = "rstanarm")