Conditionally Count in dplyr

Question

I have some member order data that I would like to aggregate by week of order.

This is what the data looks like:

memberorders=data.frame(MemID=c(\'A\         


        

Answer 1

Using the plyr package one could do

ddply(memberorders,.(MemID),
                    summarise, 
                    val1 = sum(value[week<=2]), 
                    val2 = sum(value[week<=4]),
                    val3 = length(value[week<=2]),
                    val4 = length(value[week<=4]))

  MemID val1 val2 val3 val4
1     A   30   30    2    2
2     B   10   20    1    2
3     C    5   35    1    2
4     D    3    3    1    1

Answer 2

Using both previews ideas and keeping it consistent:

MemberLTV_2 <- memberorders %>%

group_by(MemID) %>%
summarize(

    count2 = length(value[week<=2]),
    count4 = length(value[week<=4]),
    sum2 = sum(value[week<=2]),
    sum4 = sum(value[week<=4])

    )

Answer 3

Try

 library(dplyr)
 memberorders %>% 
        group_by(MemID) %>% 
        summarise(sum2= sum(value[week<=2]), sum4= sum(value[week <=4]), 
                  count2=sum(week<=2), count4= sum(week<=4))