Use column index instead of name in group_by

Question

I want to summarize a dataframe with dplyr, like so:

> test <-data.frame(ID = c(\"A\", \"A\", \"B\", \"B\"), val = c(1:4))
> test %>% group_by(ID         


        

Answer 1

You can use the across functionality as of version 1.0.0:

library(dplyr)
test %>% 
  group_by(across(1)) %>% 
  summarise(av = mean(val))
## A tibble: 2 x 2
#  ID       av
#   
#1 A       1.5
#2 B       3.5