Strange class output in brms model

General
1

I am having trouble running a model that worked fine a few months ago. This is a model from Solomon Kurz blog ( Notes on the Bayesian cumulative probit)

When I look at the Estimate of the model, it has started to return it with class '[1] “pillar_num” “pillar_vctr” “vctrs_vctr”
[4] “double” ’
I really have no idea what is going on, and why this is happening, it used to return it as numeric.

#load the packages
library(tidyverse)
library(brms)
library(tidybayes)
library(psych)

#get some data
set.seed(1)

d <- psych::bfi %>% 
  mutate(male = ifelse(gender == 1, 1, 0),
         female = ifelse(gender == 2, 1, 0)) %>% 
  drop_na() %>% 
  slice_sample(n = 200) %>% 
  mutate(id = 1:n()) %>% 
  select(id, male, female, N1:N5) %>% 
  pivot_longer(N1:N5, names_to = "item", values_to = "rating")


#run the model
fit1 <- brm(
  data = d,
  family = cumulative(probit),
  rating ~ 1,
  prior = c(prior(normal(-0.97, 1), class = Intercept, coef = 1),
            prior(normal(-0.43, 1), class = Intercept, coef = 2),
            prior(normal( 0.00, 1), class = Intercept, coef = 3),
            prior(normal( 0.43, 1), class = Intercept, coef = 4),
            prior(normal( 0.97, 1), class = Intercept, coef = 5)),
  cores = 4,
  seed = 1,
  init_r = 0.2
)

#summarise the model
 summary<-summary(fit1)

#check the class of the estimate
class(summary$fixed$Estimate)
#[1] "pillar_num"  "pillar_vctr" "vctrs_vctr" 
#[4] "double"

I’m sure this was not the class of the estimate when I last ran this, have I got it wrong? I need it to be a normal number format so I can pull it into the write up of my results.

Many thanks

2

What version(s) of brms are you using?

3

brms_2.18.0

1 Like
4

@GabriellaS-K, it looked like you made some progress on social media. Is this resolved, or do you still need help?

5

It isn’t resolved but my work around is reclassifying each estimate individually as.numeric which gets it to a format I can work with! However not everyone has been able to reproduce my error, which suggests that it’s a package/update issue, though everything is the latest version, I checked and updated where appropriate.

TLDR I don’t need help anymore but the issue is still an issue

1 Like