diagnostic-quantities {brms}R Documentation

Extract Diagnostic Quantities of brms Models

Description

Extract quantities that can be used to diagnose sampling behavior of the algorithms applied by Stan at the back-end of brms.

Usage

## S3 method for class 'brmsfit'
log_posterior(object, ...)

## S3 method for class 'brmsfit'
nuts_params(object, pars = NULL, ...)

## S3 method for class 'brmsfit'
rhat(object, pars = NULL, ...)

## S3 method for class 'brmsfit'
neff_ratio(object, pars = NULL, ...)

Arguments

object

A brmsfit object.

...

Arguments passed to individual methods.

pars

An optional character vector of parameter names. For nuts_params these will be NUTS sampler parameter names rather than model parameters. If pars is omitted all parameters are included.

Details

For more details see bayesplot-extractors.

Value

The exact form of the output depends on the method.

Examples

## Not run: 
fit <- brm(time ~ age * sex, data = kidney)

lp <- log_posterior(fit)
head(lp)

np <- nuts_params(fit)
str(np)
# extract the number of divergence transitions
sum(subset(np, Parameter == "divergent__")$Value)

head(rhat(fit))
head(neff_ratio(fit))

## End(Not run)

[Package brms version 2.15.0 Index]