Why is the function work after doing fix() in R

Question

Here's what had happened:

> NA.of.df = which(rowSums(is.na(df)) == ncol(df))
> NA.of.df 
named integer(0)
> fix(df) # i want to see what's in here -- nothing wrong
> NA.of.df # so i run it again  
1 3 5 7 9 # it works!

why would this happens??

A producible example (but doesn't seems like any data structure with dput()) is like the following:

> dput(NA.of.df)
structure(integer(0), .Names = character(0))

and NA.of.df is just the code for finding rows with all NAs (obtained from here: Remove rows in R matrix where all data is NA). (i.e. NA.of.df = which(rowSums(is.na(df)) == ncol(df)))

@akrun df is a >10,000 rows df, I will see if I can make a toy data; however, do you know why this happens? — Math Avengers, Jun 06 '20 at 23:48
I am not able to reproduce with `NA.of.df <- which(rowSums(is.na(head(mtcars))) == ncol(mtcars))` — akrun, Jun 06 '20 at 23:49
Can you try on a fresh R session. May be some of the NA have quotes around it and after the `fix`, it may have evaluated to remove those quotes? — akrun, Jun 06 '20 at 23:52
@akrun OHHHH!!! That's it! Thanks! Do you want to submit this as an answer? — Math Avengers, Jun 07 '20 at 00:01

score 2 · Accepted Answer · answered Jun 07 '20 at 00:03

2

It could be an issue with quotes around the NA resulting in is.na to not pick up those elements

is.na(c(NA, "NA"))
#[1]  TRUE FALSE

After doing the fix, it may have dropped the quotes and evaluate it correctly

answered Jun 07 '20 at 00:03

akrun

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Why is the function work after doing fix() in R

1 Answers1