Extraction of family level parameters

Interfaces brms
1

The standard way (I think) to extract specific parameters from brsm (and other) fits is to use extractor functions like coef, fixef and ranef. This extracts the population and group level parameters. Is there a standard way to extract the family level parameters?

A simple example, where the family level parameter is sigma:

my_model <- brm(hp ~ mpg + (1 | cyl), mtcars)
fixef(my_model)
ranef(my_model)
coef(my_model)    # just combines fixef and ranef
sigma(my_model) #This isn't defined for brms

We can use the draws directly to get the answer, e.g.:

mean(as.data.frame(my_model)$sigma)
  • Operating System: Linux mint 19.1
  • brms Version: 2.7.0
1 Like
2

I would use as.data.frame() in the way you did. You may also use posterior_summary(as.data.frame(my_model)$sigma)