Use dplyr's summarise and summarise_each together?

Question

I would like to apply dplyr::summarise and dplyr::summarise_each at the same time for a grouped data frame. Is it possible?

My data looks like this:

mydf <- data.frame(
    id = c(rep(1,2), rep(2, 3), rep(3, 4)), 
    amount = c(rep(1,4), rep(2,5)), 
    type1 = c(rep(1, 2), rep(0, 7)),
    type2 = c(rep(0, 4), rep(1, 5))
)
mydf
#  id amount type1 type2
#1  1      1     1     0
#2  1      1     1     0
#3  2      1     0     0
#4  2      1     0     0
#5  2      2     0     1
#6  3      2     0     1
#7  3      2     0     1
#8  3      2     0     1
#9  3      2     0     1

I would like to sum over id the amount variable and get the max for the type variables. I know I can do this as follows:

mydf %>% 
    group_by(id) %>% 
    summarise(amount = sum(amount), type1 = max(type1), type2 = max(type2))

However, I have a lot of type variables so I would prefer something like this (but with the sum of amount as well).

mydf %>%
    group_by(id) %>%
    summarise_each(funs(max), matches("type"))

Answer 1

Using dplyr

library(dplyr)

mydf %>% 
     group_by(id) %>% 
     mutate(amount = sum(amount)) %>% 
     mutate_each(funs(max), matches("type")) %>%
     unique

#Source: local data table [3 x 4]

#  id amount type1 type2
#1  1      2     1     0
#2  2      4     0     1
#3  3      8     0     1

Or simply as @HongOoi indicated

mydf %>% 
     group_by(id) %>% 
     mutate(amount=sum(amount)) %>% 
     summarise_each(funs(max))