R how cbind two data.frames next to each other, filling unequal rows with NAs

Question

How to simply "paste" two data frames next to each other, filling unequal rows with NAs (e.g. because I want to make a "kable" or sth similar)?

df1 <- data.frame(a = c(1,2,3),
                  b = c(3,4,5))

df2 <- data.frame(a = c(4,5),
                  b = c(5,6))

# The desired "merge"

a b a b
1 3 4 5
2 4 5 6
3 5 NA NA

Have you tried solutions from this post? https://stackoverflow.com/questions/3699405/how-to-cbind-or-rbind-different-lengths-vectors-without-repeating-the-elements-o — Ronak Shah, Dec 03 '20 at 07:55

score 0 · Answer 1 · answered Dec 03 '20 at 08:00

Thanks to Ronak Shah, I found an easy answer in the answers to this post: How to cbind or rbind different lengths vectors without repeating the elements of the shorter vectors?

Without having to hack anything together, one can use cbind.na from the qpcR: package:

df1 <- data.frame(a = c(1,2,3),
                  b = c(3,4,5))

df2 <- data.frame(a = c(4,5),
                  b = c(5,6))

comb <- qpcR:::cbind.na(df1, df2)

As this answer is 4 years old, I wonder if there are more "modern" solutions in the popular packages like tidyverse et. al.

score 0 · Answer 2 · answered Dec 03 '20 at 08:05

0

In base R you could do:

nr <- max(nrow(df1), nrow(df2))
cbind(df1[1:nr, ], df2[1:nr, ])
#   a b  a  b
# 1 1 3  4  5
# 2 2 4  5  6
# 3 3 5 NA NA

answered Dec 03 '20 at 08:05

s_baldur

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R how cbind two data.frames next to each other, filling unequal rows with NAs

2 Answers2