group_by not grouping by selected variables

[idontknow]

Hello! I am trying the following code but it does not group by the selected variables and I am not sure how to debug it.

y<- sample_final %>% 
              group_by(a,b) %>% 
              summarise(
                avg= mean(y)
              )

Anyone knows why? Thanks!

[jrkrideau]

You are trying to summarize a non-existant tibble or data.frame. You need to be summarizing a variable in sample_final

Try this"

sample_final  <- data.frame(a = rep(1:2, 10, replace = TRUE),b = rep(c("x", "y"), 10, replace = TRUE), c = c(1,3,7,9,5,12,4, 5,9,6))

y <- sample_final %>% 
  group_by(a, b) %>% 
  summarise(avg= mean(c))