Home Summarizing multiple columns with dplyr?
 This question already has an answer here: Aggregate / summarize multiple variables per group (e.g. sum, mean) 4 answers Can dplyr summarise over several variables without listing each one? [duplicate] 2 answers I'm struggling a bit with the dplyr-syntax. I have a data frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R. df <- data.frame( a = sample(1:5, n, replace = TRUE), b = sample(1:5, n, replace = TRUE), c = sample(1:5, n, replace = TRUE), d = sample(1:5, n, replace = TRUE), grp = sample(1:3, n, replace = TRUE) ) df %>% group_by(grp) %>% summarise(mean(a))  This gives me the mean for column "a" for each group indicated by "grp". My question is: is it possible to get the means for each column within each group at once? Or do I have to repeat df %>% group_by(grp) %>% summarise(mean(a)) for each column? What I would like to have is something like df %>% group_by(grp) %>% summarise(mean(a:d)) # "mean(a:d)" does not work