# stanreg-methods

##### Methods for stanreg objects

The methods documented on this page are actually some of the least important
methods defined for stanreg objects. The most
important methods are documented separately, each with its own page. Links to
those pages are provided in the **See Also** section, below.

##### Usage

```
# S3 method for stanreg
coef(object, ...)
```# S3 method for stanreg
confint(object, parm, level = 0.95, ...)

# S3 method for stanreg
fitted(object, ...)

# S3 method for stanreg
nobs(object, ...)

# S3 method for stanreg
residuals(object, ...)

# S3 method for stanreg
se(object, ...)

# S3 method for stanreg
update(object, formula., ..., evaluate = TRUE)

# S3 method for stanreg
vcov(object, correlation = FALSE, ...)

# S3 method for stanreg
fixef(object, ...)

# S3 method for stanreg
ngrps(object, ...)

# S3 method for stanreg
ranef(object, ...)

# S3 method for stanreg
sigma(object, ...)

# S3 method for stanreg
VarCorr(x, sigma = 1, ...)

##### Arguments

- object, x
A fitted model object returned by one of the rstanarm modeling functions. See

`stanreg-objects`

.- ...
Ignored, except by the

`update`

method. See`update`

.- parm
For

`confint`

, an optional character vector of parameter names.- level
For

`confint`

, a scalar between \(0\) and \(1\) indicating the confidence level to use.- formula., evaluate
See

`update`

.- correlation
For

`vcov`

, if`FALSE`

(the default) the covariance matrix is returned. If`TRUE`

, the correlation matrix is returned instead.- sigma
Ignored (included for compatibility with

`VarCorr`

).

##### Details

The methods documented on this page are similar to the methods defined for objects of class 'lm', 'glm', 'glmer', etc. However there are a few key differences:

`residuals`

Residuals are

*always*of type`"response"`

(not`"deviance"`

residuals or any other type). However, in the case of`stan_polr`

with more than two response categories, the residuals are the difference between the latent utility and its linear predictor.`coef`

Medians are used for point estimates. See the

*Point estimates*section in`print.stanreg`

for more details.`se`

The

`se`

function returns standard errors based on`mad`

. See the*Uncertainty estimates*section in`print.stanreg`

for more details.`confint`

For models fit using optimization, confidence intervals are returned via a call to

`confint.default`

. If`algorithm`

is`"sampling"`

,`"meanfield"`

, or`"fullrank"`

, the`confint`

will throw an error because the`posterior_interval`

function should be used to compute Bayesian uncertainty intervals.

##### See Also

The

`print`

,`summary`

, and`prior_summary`

methods for stanreg objects for information on the fitted model.`launch_shinystan`

to use the ShinyStan GUI to explore a fitted rstanarm model.The

`plot`

method to plot estimates and diagnostics.The

`pp_check`

method for graphical posterior predictive checking.The

`posterior_predict`

and`predictive_error`

methods for predictions and predictive errors.The

`posterior_interval`

and`predictive_interval`

methods for uncertainty intervals for model parameters and predictions.The

`loo`

,`kfold`

, and`log_lik`

methods for leave-one-out or K-fold cross-validation, model comparison, and computing the log-likelihood of (possibly new) data.The

`as.matrix`

,`as.data.frame`

, and`as.array`

methods to access posterior draws.

*Documentation reproduced from package rstanarm, version 2.18.2, License: GPL (>= 3)*