在带有管道函数的向量中应用 is.na() 函数

Question

I was experimenting with the pipe function from dplyr , and running below code without success -

library(dplyr)
12 %>% ifelse(is.na(.), FALSE, TRUE)
### Error in ifelse(., is.na(.), FALSE, TRUE) : unused argument (TRUE)

Any pointer why I am getting this error? What is the correct approach if I want to use pipe ?

Answer 1

Another option is to unnest the functions further.

12 %>% is.na %>% ifelse(FALSE, TRUE)
# TRUE

Answer 2

We can use is.na directly in the pipeline rather than nesting it:

12 %>% is.na %>% ifelse(FALSE, TRUE)

or

12 %>% is.na %>% `!`

or

library(magrittr)
12 %>% is.na %>% not

or

12 %>% (is.na %>% Negate)

Answer 3

There are several possibilities:

Using brackets : As @tmfmnk pointed out, one should use {} to get that behavior in pipe :

 library(dplyr)
 vec <- c(12,13, NA)
 vec %>% {ifelse(is.na(.), FALSE,TRUE)}
 # TRUE  TRUE FALSE

Unnesting : Alternatively, as @Ands pointed out, one can unnest the functions:

12 %>% is.na %>% ifelse(FALSE, TRUE)

Answer 4

library(dplyr)
12 %>% ifelse(is.na(.), FALSE)
#FALSE

this works for me