predictive_error.brmsfit {brms} R Documentation

## Posterior Draws of Predictive Errors

### Description

Compute posterior draws of predictive errors, that is, observed minus predicted responses. Can be performed for the data used to fit the model (posterior predictive checks) or for new data.

### Usage

## S3 method for class 'brmsfit'
predictive_error(
object,
newdata = NULL,
re_formula = NULL,
re.form = NULL,
resp = NULL,
ndraws = NULL,
draw_ids = NULL,
sort = FALSE,
...
)


### Arguments

 object An object of class brmsfit. newdata An optional data.frame for which to evaluate predictions. If NULL (default), the original data of the model is used. NA values within factors are interpreted as if all dummy variables of this factor are zero. This allows, for instance, to make predictions of the grand mean when using sum coding. re_formula formula containing group-level effects to be considered in the prediction. If NULL (default), include all group-level effects; if NA, include no group-level effects. re.form Alias of re_formula. resp Optional names of response variables. If specified, predictions are performed only for the specified response variables. ndraws Positive integer indicating how many posterior draws should be used. If NULL (the default) all draws are used. Ignored if draw_ids is not NULL. draw_ids An integer vector specifying the posterior draws to be used. If NULL (the default), all draws are used. sort Logical. Only relevant for time series models. Indicating whether to return predicted values in the original order (FALSE; default) or in the order of the time series (TRUE). ... Further arguments passed to prepare_predictions that control several aspects of data validation and prediction.

### Value

An S x N array of predictive error draws, where S is the number of posterior draws and N is the number of observations.

### Examples

## Not run:
## fit a model
fit <- brm(rating ~ treat + period + carry + (1|subject),
data = inhaler, cores = 2)

## extract predictive errors
pe <- predictive_error(fit)
str(pe)

## End(Not run)



[Package brms version 2.17.0 Index]