how to migrate multiple data frames into one in R

Question

I have multiple data frames, for example: data frame 1

  V1 V2
1 Charlie 30
2 Tom 50
3 Anna 20

data frame 2

  V1 V2
1 Tom 30
2 Anna 10
3 Julia 60

how can I migrate these data frame into same one and add the second columns if the first column value was same:

  V1 V2
1 Charlie 30
2 Tom 80
3 Anna 30
4 Julia 60

A similar question: http://stackoverflow.com/q/5769320/ – Frank Feb 26 '17 at 07:27 — Frank, Feb 26 '17 at 07:27

score 3 · Answer 1 · answered Feb 26 '17 at 07:11

We can use tidyverse. We use bind_rows to bind the multiple datasets together, then grouped by 'V1', get the sum of 'V2'

library(tidyverse)
bind_rows(df1,df2) %>%
        group_by(V1) %>% 
        summarise(V2 = sum(V2))

Or using data.table, we can place the datasets in a list, use rbindlist to bind the datasets in the list, then grouped by 'V1', get the sum of 'V2'

library(data.table)
rbindlist(list(df1, df2))[, .(V2 = sum(V2)), by = V1]

Or with base R, by rbinding the datasets, use aggregate to get the sum of 'V2' grouped by 'V1'

aggregate(V2 ~V1, rbind(df1, df2), FUN = sum)
#       V1 V2
#1    Anna 30
#2 Charlie 30
#3   Julia 60
#4     Tom 80

how to migrate multiple data frames into one in R

1 Answers1