CODEWITHSUNDEEP
rlistdataframe
maexkk
maexkk

Reputation: 1

Adding list elements as a columns of a data frame

I was wondering if there is a possibility to add list elements as columns of a data frame.

e.g. I have defined a list

a <- c(1, 2, 3, 4, 5)

and I would like to add it as the columns of my data frame

df <- data.frame(matrix(ncol = 3, nrow = 2500))
x <- c("P", "B", "R")
colnames(df) <- x

My data frame has already values included in columns P, B & R.

Now I would like to add my list a as new columns without any values (alternative it could also be 0) in each of the rows.

In the end my data frame should have the columns P, B, R, 1, 2, 3, 4, 5.

I was thinking about doing it with 'cbind()' or addressing the data frame directly but this does not seem to work. Can anyone please help me on that?

Upvotes: 0

Views: 723

Answers (3)

akrun
akrun

Reputation: 887851

We can also wrap with paste0 to convert to character

df[paste0(a)] <- NA

An option with add_column

library(tibble)
add_column(df, !!! setNames(rep(list(NA), length(a)), a))

We can specify the .after or .before to add the columns in a specific location.

Upvotes: 2

s_baldur
s_baldur

Reputation: 33603

You could do:

df[as.character(a)] <- NA

> head(df)
   P  B  R  1  2  3  4  5
1 NA NA NA NA NA NA NA NA
2 NA NA NA NA NA NA NA NA
3 NA NA NA NA NA NA NA NA
4 NA NA NA NA NA NA NA NA
5 NA NA NA NA NA NA NA NA
6 NA NA NA NA NA NA NA NA

Just note that having column names starting with a number is not good practice.

Upvotes: 2

ThomasIsCoding
ThomasIsCoding

Reputation: 102625

I think the approach by @sindri_baldur is sufficiently simple already.

Here is another base R option but a bit more complicated

cbind(df,setNames(rep(list(NA),length(a)),a))

Upvotes: 0

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