brms (version 0.5.0)

residuals.brmsfit: Extract Model Residuals from brmsfit Objects

Description

Extract Model Residuals from brmsfit Objects

Usage

## S3 method for class 'brmsfit':
residuals(object, re_formula = NULL, type = c("ordinary",
  "pearson"), summary = TRUE, probs = c(0.025, 0.975), ...)

Arguments

object

An object of class brmsfit

re_formula

formula containing random effects to be considered in the prediction. If NULL (default), include all random effects; if NA, include no random effects. Other options will be implemented in the future.

type

The type of the residuals, either "ordinary" or "pearson". More information is provided under 'Details'.

summary

logical. Should summary statistics (i.e. means, sds, and 95% intervals) be returned instead of the raw values. Default is TRUE

probs

The percentiles to be computed by the quantile function. Only used if summary is TRUE.

...

Currently ignored

Value

• Model residuals. If summary = TRUE this is a N x C matrix and if summary = FALSE a S x N matrix, where S is the number of samples, N is the number of observations, and C is equal to length(probs) + 2.

Details

Residuals of type ordinary are of the form $R = Y - Yp$, where $Y$ is the observed and $Yp$ is the predicted response. Residuals of type pearson are of the form $R = (Y - Yp) / Var(Y)$, where $Var(Y)$ is an estimation of the variance of $Y$. Currently, residuals.brmsfit does not support categorical or ordinal models.

Examples

## fit a model
fit <- brm(rating ~ treat + period + carry + (1|subject), data = inhaler,
           n.cluster = 2)

## extract residuals
res <- residuals(fit, summary = TRUE)
head(res)