combine two dataframes in R based on common columns

Question

I have to combine two data-frames which look like this I want to take the common column among the data-frames and join them together. Rows in two data-frames will be completely different.

      a  b c 
row1  1  0 1      
row2  1  0 1

another dataframe

     d a c f
row3 1 0 1 1
row4 1 1 0 0

I want the final dataset to look like this

        a c 
row1    1 1
row2    1 1
row3    0 1
row4    1 0

Here is the dput from two dataframes

dput(x1)
structure(list(d = c(1L, 1L), a = 0:1, c = c(1L, 0L), f = c(1L, 
0L)), .Names = c("d", "a", "c", "f"), row.names = c("row3", "row4"
), class = "data.frame")

dput(x2)
structure(list(a = c(1L, 1L), b = c(0L, 0L), c = c(1L, 1L)), .Names = c("a", 
"b", "c"), row.names = c("row1", "row2"), class = "data.frame")

user1609452 · Accepted Answer · 2013-05-21T16:36:51.463

6

You could get the common names and then use row bind:

common <- intersect(names(x1), names(x2))
rbind(x1[,common], x2[,common])
     a c
row3 0 1
row4 1 0
row1 1 1
row2 1 1

EDIT: To match your expected output

 rbind(x2[,common], x1[,common])
     a c
row1 1 1
row2 1 1
row3 0 1
row4 1 0

edited May 21 '13 at 16:36

answered May 21 '13 at 16:09

user1609452

4,406
1
15
20

Hi I just have one more doubt.How can I print row3 and row4 once after row1 and once after row2? – dissw.geek9 May 21 '13 at 16:30

score 1 · Answer 2 · answered May 21 '13 at 16:11

1

A very rudimentary version

> X <- merge(x1, x2, all=TRUE)
> X[, which(colSums(!is.na(X))==nrow(X))]
  a c
1 0 1
2 1 0
3 1 1
4 1 1

answered May 21 '13 at 16:11

Jilber Urbina

58,147
10
114
138

combine two dataframes in R based on common columns

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