CODEWITHSUNDEEP
rdplyr
bers
bers

Reputation: 5771

Why do I get "Error: `...` is not empty" in R?

I'm a Python guy who is asked to run some R code that returns the following error:

Error: ... is not empty.

We detected these problematic arguments:

  • ..1

These dots only exist to allow future extensions and should be empty. Did you misspecify an argument? Run rlang::last_error() to see where the error occurred.

I could reduce the code to this MWE:

library(dplyr)
x <- data.frame(1)
x %>% ungroup(x)

I have no idea what line 3 is supposed to do, but it fails on my system (dplyr 1.0.0), while working using dplyr 0.8.5 or on https://rdrr.io/snippets/, where it prints

  X1
1  1

I have tried a number of things, with no success:

update.packages(ask = FALSE)
remove.packages("dplyr")
install.packages("dplyr")

What is going on here? How can I (help) investigate?

Update: options(error = recover) gives me this:

 1: x %>% ungroup(x)
 2: withVisible(eval(quote(`_fseq`(`_lhs`)), env, env))
 3: eval(quote(`_fseq`(`_lhs`)), env, env)
 4: eval(quote(`_fseq`(`_lhs`)), env, env)
 5: `_fseq`(`_lhs`)
 6: freduce(value, `_function_list`)
 7: withVisible(function_list[[k]](value))
 8: function_list[[k]](value)
 9: ungroup(., x)
10: ungroup.data.frame(., x)
11: ellipsis::check_dots_empty()
12: action_dots(action = action, message = "`...` is not empty.", dot_names = n
13: action(message, .subclass = c(.subclass, "rlib_error_dots"), ...)
14: signal_abort(cnd)

Another update: the complete line of code, non-minimized, if that matters, is

screenData <- mutate_if(screenData, is.character, as.factor) %>% ungroup(screenData)

Maybe that makes more sense than my MWE.

Another one: dput(screenData) returns

structure(list(wellID = "A001", rowID = "A0", colID = "01", value = 0, 
    fileName = "V3_Prob5_p1", batch = structure(NA_integer_, .Label = character(0), class = "factor"), 
    sampleID = NA, patientID = NA, name = NA_character_, concentration = NA_real_, 
    wellType = "sample"), row.names = c(NA, -1L), class = c("tbl_df", 
"tbl", "data.frame"))

Finally, I opened an issue with the maintainer of the code, see https://github.com/lujunyan1118/DrugScreenExplorer/issues/1, and with dplyr, see https://github.com/tidyverse/dplyr/issues/5368

Upvotes: 1

Views: 7428

Answers (3)

Ahmed El-Gabbas
Ahmed El-Gabbas

Reputation: 527

It seems an issue with tibble package. See here.

Updating tibble solved the issue for me.

Upvotes: 0

Limey
Limey

Reputation: 12451

The pipe %>% is syntactic sugar. It means "take the object on the left hand side of the pipe and use it as the first argument to the function on the right-hand side of the pipe".

So you can say ungroup(x) or x %>% ungroup(), both of which work, but x %>% ungroup(x) is trying to both ungroup a data.frame called x and remove a variable called x from the grouping of the data.frame called x. But the data.frame x doesn't contain a variable called x. Hence the problem.

The code you've been given is inherently wrong (or at the very least confusingly written).

Update Following the post of your dput.

screenData %>% ungroup(screenData) is equivalent to ungroup(screenData, screenData) where the first screenData is the data.frame to ungroup and the second is the name of the variable in the data.frame to remove from the grouping. but the data.frame screenData does not contain a column called screenData. That's why you get an error.

The code you have been given is unequivocally incorrect.

The fact that it ran without error in a previous version of dplyr is purely accidental.

Upvotes: 4

Konrad Rudolph
Konrad Rudolph

Reputation: 545508

The ungroup function takes no extra arguments. The code you’ve been provided with is wrong. Remove x from the ungroup call.

Upvotes: 1

Related Questions