CODEWITHSUNDEEP
rtidyr
arnyeinstein
arnyeinstein

Reputation: 1013

gather from tidyr compains about object not found

I had this snippet of working code:

number_of_columns <-  dim(resultsper)[2]
resultsper <- resultsper %>% gather(c(5:number_of_columns), key = "Scenario", value = "Value")

This used to work fine, but now, I get the message

Error in FUN(X[[i]], ...) : object 'number_of_columns' not found.

If I run 

resultsper <- resultsper %>% gather <- (c(5:11), key = "Scenario", value = "Value")

It works again, but this is not what I want. I tried gather_ but this also doesn't work. It might be an update of tidyr, but I haven't found a solution yet.

Thanks in advance

Renger

Upvotes: 1

Views: 1894

Answers (1)

aosmith
aosmith

Reputation: 36076

Starting in tidyr 0.7.0, selecting rules are more strict. A review of all the changes in versino 0.7.0 can be found in this article.

In a nutshell, when using a context expression (i.e., using information outside the dataset) you must be explicit on where to find the objects by using the quasiquotation operator !!.

Here is an example of what that would look like in your scenario.

number_of_columns =  ncol(mtcars)

mtcars %>% gather("Scenario", "Value", !! 5:number_of_columns)

Upvotes: 1

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