CODEWITHSUNDEEP
rdataframe
costebk08
costebk08

Reputation: 1359

Merge data-frames by row with unequal dimensions in R

Let's say I have the following data-frames:

a<-data.frame(A=3,B=9,C=10,D=6)
print(a)
  A B  C D
1 3 9 10 6
b<-data.frame(A=1,B=2,D=5)
print(b)
  A B D
1 1 2 5

I am trying to bind these together by row so that the corresponding column names line up, and NAs are yielded where corresponding values are missing so that the final result is:

  print(c)
  A B C  D
1 3 9 6  10
2 1 2 NA 5

I have tried the following:

rbind(a,b)
merge(a,b,byrow=TRUE)

But neither work, any suggestions? Thank you!

Upvotes: 1

Views: 544

Answers (2)

akrun
akrun

Reputation: 887138

We can use rbindlist from data.table. We keep the data.frames in a list and use rbindlist with the option fill=TRUE to generate NA for missing columns in a dataset.

library(data.table)
rbindlist(list(a,b), fill=TRUE)
#   A B  C D
#1: 3 9 10 6
#2: 1 2 NA 5

Another option is bind_rows from dplyr which is an efficient implementation of do.call(rbind, ...) for row binding many dataframes together.

library(dplyr)
bind_rows(a,b)
#Source: local data frame [2 x 4]

#    A     B     C     D
#  (dbl) (dbl) (dbl) (dbl)
#1     3     9    10     6
#2     1     2    NA     5

Upvotes: 3

Tad Dallas
Tad Dallas

Reputation: 1189

You could use joins, as implemented in dplyr. 

full_join(a,b)

   Joining by: c("A", "B", "D")
     A B  C D
   1 3 9 10 6
   2 1 2 NA 5

Upvotes: 2

Related Questions