This method is primarily intended to be used only for models fit using 
optimization. For models fit using MCMC or one of the variational
approximations, see posterior_predict.
# S3 method for stanreg
predict(
  object,
  ...,
  newdata = NULL,
  type = c("link", "response"),
  se.fit = FALSE
)A fitted model object returned by one of the 
rstanarm modeling functions. See stanreg-objects.
Ignored.
Optionally, a data frame in which to look for variables with which to predict. If omitted, the model matrix is used.
The type of prediction. The default 'link' is on the scale
of the linear predictors; the alternative 'response' is on the scale
of the response variable.
A logical scalar indicating if standard errors should be 
returned. The default is FALSE.
A vector if se.fit is FALSE and a list if se.fit
  is TRUE.