Can I group_by columns with starts_with?

Question

I'm dealing with a big dataframe that has a number of columns I want to group by. I'd like to do something like this:

output <- df %>% 
  group_by(starts_with("GEN", ignore.case=TRUE),x,y) %>% 
  summarize(total=n()) %>% 
  arrange(desc(total))

is there a way to do this? Maybe with group_by_at or some other similar function?

Answer 1

To use starts_with() in group_by(), you need to wrap it in across(). Here is an example using some built data.

library(dplyr)
mtcars %>%
group_by(across(starts_with("c"))) %>%
summarize(total = n()) %>%
arrange(-total)

# A tibble: 9 x 3
# Groups:   cyl [3]
    cyl  carb total
  <dbl> <dbl> <int>
1     4     2     6
2     8     4     6
3     4     1     5
4     6     4     4
5     8     2     4
6     8     3     3
7     6     1     2
8     6     6     1
9     8     8     1