[SOLVED] Extract the "model comparisons" table from a loolist object

Extract the "model comparisons" table from a loolist object

I would like to extract the "Model comparisons" table as a dataframe/matrix from a loolist object.

data(iris)

m1 <- brm(Sepal.Length~Sepal.Width,data=iris)
m2 <- brm(Sepal.Length~Sepal.Width + Petal.Length,data=iris)


looLst <- loo(m1,m2,compare=TRUE)

print(looLst)

This will print a long text summary, the end of which is

Model comparisons:
   elpd_diff se_diff
m2    0.0       0.0 
m1 -135.4      10.4

Is it possible to extract this table from the loolist object?

Solution

You could extract it from the object and write a custom function to add the text "Model comparisons:" with cat like this:

data(iris)
library(brms)
m1 <- brm(Sepal.Length~Sepal.Width,data=iris)
m2 <- brm(Sepal.Length~Sepal.Width + Petal.Length,data=iris)

looLst <- loo(m1,m2,compare=TRUE)
your_table <- function(df) {
  cat("Model comparisons: \n")
  df$diffs
}
your_table(looLst)
#> Model comparisons:
#>    elpd_diff se_diff
#> m2    0.0       0.0 
#> m1 -135.5      10.4

^{Created on 2023-04-21 with reprex v2.0.2}