R Remove an integer element from a factor-type vector

Question

I have the vector foo:

> foo

 983      984      985      986      987      988      989      990
cluster4 cluster4 cluster4 cluster1 cluster1 cluster1 cluster5 cluster5

Levels: cluster1  cluster4 cluster5  


typeof(foo)

    "integer"

class(foo)

    "factor"

How could I remove the element "983"? So I get:

> foo_removed

 984      985      986      987      988      989      990
cluster4 cluster4 cluster1 cluster1 cluster1 cluster5 cluster5

Levels: cluster1  cluster4 cluster5 

Answer 1

We could use !is.na(as.numeric()) to identify the strings that are numeric and remove them.

onlynumbers <- "123.4"
onlyletters <- "abcd."
strings <- c(onlynumbers, onlyletters)
!is.na(as.numeric(strings))
[1]  TRUE FALSE

As you can see this is working, now the removal

result <- strings[is.na(as.numeric(strings))]
> result
[1] "abcd."

---

EDIT You should first convert your factors to character using as.character.factor and after you can reconvert using as.factor

---

EDIT 2 to keep the names you could use names(result) <- names(strings)[is.na(as.numeric(strings))]