[SOLVED] In the rstatix function anova_test, how do I get both ges and pes as effect sizes?

In the rstatix function anova_test, how do I get both ges and pes as effect sizes?

It says here that one can get one or the other or both. I have been able to get each one separately but not both together even when I set effect.size = c("ges", "pes"). Instead, I only get "pes". I have the same problem when I use my own data and when I use the hangover dataset from the {WRS2} package. For the hangover data, my code is:

anova_test(data = hangover, dv = symptoms, wid = id, between = group, within = time, effect.size = c("ges", "pes"))

I would be very grateful for your help!

Solution

This seems to be an error in either the docs or the code. The docs do say you can specify both, but the relevant code uses if / else to return just one or the other:

add_anova_effect_size <- function(res.anova.summary, effect.size = "ges",  observed = NULL){
  ss.exists <- "SSn" %in% colnames(res.anova.summary$ANOVA)
  if(!ss.exists){
    return(res.anova.summary)
  }
  if("pes" %in% effect.size){
    res.anova.summary <- res.anova.summary %>%
      add_partial_eta_squared()
  }
  else {
    res.anova.summary <- res.anova.summary %>%
      add_generalized_eta_squared(observed)
  }
  res.anova.summary
}

But also, as discussed here and mentioned by @Phenomniverse, rstatix currently calculates ges incorrectly.