dplyr - using mutate() like rowmeans()

Question

I can\'t find the answer anywhere.

I would like to calculate new variable of data frame which is based on mean of rows.

For example:

data &l         


        

Answer 1

You're looking for

data %>% 
    rowwise() %>% 
    mutate(c=mean(c(a,b)))

#      id     a     b     c
#   (dbl) (dbl) (dbl) (dbl)
# 1   101     1     2   1.5
# 2   102     2     2   2.0
# 3   103     3     2   2.5

or

library(purrr)
data %>% 
    rowwise() %>% 
    mutate(c=lift_vd(mean)(a,b))