R: how to merge 2 data frames by column name

Question

apple = data.frame(Obs = c(1:4), Color = c("red", "red", "red", "green"), Weight = c(1.1, 1.2, 1.3, 1.4))
orange = data.frame(Obs = c(1:6), Weight = c(2, 3, 4, 5, 6, 7))

I have two data.frames, apple and orange, in which the latter's columns are a subset of the former's.

> apple
  Obs Color Weight
1   1   red    1.1
2   2   red    1.2
3   3   red    1.3
4   4 green    1.4
> orange
  Obs Weight
1   1      2
2   2      3
3   3      4
4   4      5
5   5      6
6   6      7

I would like to merge the 2 data.frames and the result should look something like this:

> apple_orange
      Obs Color Weight
    1   1   red    1.1
    2   2   red    1.2
    3   3   red    1.3
    4   4 green    1.4
    5   1    NA     2
    6   2    NA     3
    7   3    NA     4
    8   4    NA     5
    9   5    NA     6
    10  6    NA     7

What's a way to merge this so that I do not have the specify the specific column names? I.e. my actual dataset has hundreds of columns in common, so I'd rather not type them out one by one.

This seems more like you want to append the data frames, not merge them. You can do bind_rows(apple, orange) — svenhalvorson, May 30 '17 at 20:30

score 8 · Accepted Answer · answered May 30 '17 at 20:29

You can use dplyr::bind_rows which matches columns by name and fill missing columns with NA, here is the docs:

When row-binding, columns are matched by name, and any values that don't match will be filled with NA.

dplyr::bind_rows(apple, orange)

   Obs Color Weight
1    1   red    1.1
2    2   red    1.2
3    3   red    1.3
4    4 green    1.4
5    1  <NA>    2.0
6    2  <NA>    3.0
7    3  <NA>    4.0
8    4  <NA>    5.0
9    5  <NA>    6.0
10   6  <NA>    7.0

R: how to merge 2 data frames by column name

1 Answers1