R can't convert NaN to NA

Question

I have a data frame with several factor columns containing NaN\'s that I would like to convert to NA\'s (the NaN seems to be a problem for

Answer 1

You can't have NaN in a character vector, which is what you have here:

> tester1 <- c("2", "2", "3", "4", "2", "3", NaN)
> is.nan(tester1)
[1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE
> tester1
[1] "2"   "2"   "3"   "4"   "2"   "3"   "NaN"

Notice how R thinks this is a character string.

You can create NaN in a numeric vector:

> tester1 <- c("2", "2", "3", "4", "2", "3", NaN)
> as.numeric(tester1)
[1]   2   2   3   4   2   3 NaN
> is.nan(as.numeric(tester1))
[1] FALSE FALSE FALSE FALSE FALSE FALSE  TRUE

Then, of course, R can convert NaN to NA as per your code:

> foo <- as.numeric(tester1)
> foo[is.nan(foo)] <- NA
> foo
[1]  2  2  3  4  2  3 NA