CODEWITHSUNDEEP
r
Roger Mellie
Roger Mellie

Reputation: 1

How to reference a dynamically assigned dataframe name

I have successfully allocated dataframe names and populated them (see code) but I do not know how to subsequently reference them. So I loop through to assign df.test1 and populate it with some data 1 and so on. I know that the df has been created, and can view or summary it in the console, but not in the code.

I am pretty new to R so am not sure if some of the solutions I have looked at apply to me.

num.clusters <- 5
for (i in 1:num.clusters) {
  assign(paste("df.test",i,sep=""), paste("somedata", i))
}

This works but Then want to do something like:

View(df.test,i)

to view whatever iteration from 1 to 5.

I want to be able to use the assigned dataframes like any other dataframe. I could hard code this as View(df.test1) but that would defeat the point. I also want to do other things with the datframe, e.g. subsetting.

I know this doesn't work. Would love to know what does.

Many thanks...

Upvotes: 0

Views: 337

Answers (1)

Chris Haug
Chris Haug

Reputation: 325

Your question is the proof that the approach is problematic: avoid using assign in general because it makes accessing the variables afterwards awkward (among other issues).

A cleaner way is to just put your "data frames" (copying from your example) in a list:

num.clusters <- 5
df.test <- list()
for (i in 1:num.clusters) {
  df.test[[i]] <- paste("somedata", i)
}

Then you would just access them like this:

View(df.test[[i]])

If what you put in there was an actual data.frame (and not the strings you were using), you could then access its columns like any other data.frame:

df.test[[i]]$Name

Or

df.test[[i]][, "Name"]

Upvotes: 1

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