Using dplyr package to summarise multiple columns - R

Question

my_data <- data.frame(
    w = sample(1:5, 10, replace = TRUE), 
    x = sample(1:5, 10, replace = TRUE), 
    y = sample(1:5, 10, replace = TRUE), 
    z = sample(1:5, 10, replace = TRUE), 
    my_group = sample(1:3, 10, replace = TRUE)
)

I would want to find the mean of each column within each group. i.e i'd want the mean of columns (w,x,y,z) with rescpect to the three different groups

Answer 1

'dplyr' package provides 'summarise_all()' function to apply to all the columns collectively:

my_data %>% group_by(my_group) %>% summarise_all(funs(mean))