从R中的列表中删除“”元素

Question

I have a list where I would like to remove empty characters: "" .

I seem to be subsetting the elements incorrectly:

> sample2[which(sample2 == "")]
list()
> sample2[which(sample2 != "")]
[[1]]
 [1] ""          "03JAN1990" ""          ""          ""         
 [6] ""          "23.4"      "0.4"       ""          ""         
[11] ""          ""          "25.1"      "0.3"       ""         
[16] ""          ""          ""          "26.6"      "0.0"      
[21] ""          ""          ""          ""          "28.6"     
[26] "0.3"   

What should I do to subset and remove the empty characters?

Answer 1

From your output, it looks like sample2 is not a character vector, but it is a list containing a character vector. You should be using

sample2[[1]][which(sample2[[1]] != "")]

(It would help to include dput(sample2) just to confirm)

Or even better, take the character vector out of the list first

sample3 <- sample2[[1]]
# or maybe sample3 <- unlist(sample2)
sample3[which(sample3 != "")]

Answer 2

A very basic solution:

> lst = list(1,2,"dog","","boss","")
> x = unlist(lst)
> list(x[x!=""])
[[1]]
[1] "1"    "2"    "dog"  "boss"