CODEWITHSUNDEEP
rdataframe
jakes
jakes

Reputation: 2095

Creating an empty data frame with column names defined as a sequence

I need to create a data.frame with no rows but specified column names and column types that is about to be filled later. As I want to have 1000 columns, defining columns one by one (as seen below) is not an option. 

data.frame(a1 = character(), a2 = character(), ..., a1000 = character())

I was thinking that maybe paste function can be used to create a sequence of names, but the following doesn't work.

data.frame(paste('a', 1:1000, sep = '') = character())

Any ideas how it can be achieved?

Upvotes: 0

Views: 1059

Answers (2)

DJV
DJV

Reputation: 4873

While it's very similar to @Nick Criswell, you can also do this: 

df <- data.frame(replicate(1000,sample(0:1,0,rep=TRUE))) 

> dim(df)
[1]    0 1000
> class(df)
[1] "data.frame"

Upvotes: 3

Nick Criswell
Nick Criswell

Reputation: 1743

There might be a way to do this in one line, but an option is to first make an empty matrix, convert that to a data frame and then change the names. 

df <- data.frame(matrix("NA", nrow = 0, ncol = 1000), stringsAsFactors = FALSE)

names(df) <- paste("a", 1:1000, sep = "")

> dim(df)
[1]    0 1000
> class(df)
[1] "data.frame"

Upvotes: 1

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