Replicate data.frame using vector length & pass each element as a new column

user_2742140 0
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I have a data frame dd and a vector vec. I want to multiply the dataframe as many times as is the length of the vector. Also, I want to add this vector element as a new column to the dataframe.

# Dummy data
dd<- data.frame(id = c(1,2,3,4,5))
vec <- c("a", "b", "d")

Desired output:

  id vec
1  1 a
2  2 a
3  3 a
4  4 a
5  5 a
6  1 b
7  2 b
8  3 b
9  4 b
10 5 b
11 1 d
12 2 d
13 3 d
14 4 d
15 5 d

Originally, I would get the length(vec), use rep(vec, each = length(vec)) and then add this column to rbind(dd, dd,dd). But, if need to replicate dd twenty times, how to do this in a smarter way?

r
3 Answers

We can use crossing

library(tidyr)
crossing(dd, vec)
user_37322710

Try:

vec <- data.frame(vec)
merge(dd,vec)

Output:

   id vec
1   1   a
2   2   a
3   3   a
4   4   a
5   5   a
6   1   b
7   2   b
8   3   b
9   4   b
10  5   b
11  1   d
12  2   d
13  3   d
14  4   d
15  5   d
user_146695450

You can try rep like below

transform(
  dd,
  vec = rep(vec, each = length(id))
)

which gives

   id vec
1   1   a
2   2   a
3   3   a
4   4   a
5   5   a
6   1   b
7   2   b
8   3   b
9   4   b
10  5   b
11  1   d
12  2   d
13  3   d
14  4   d
15  5   d
user_121587570
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