Data frame AEbySOC contains two columns - factor SOC with character levels and integer count Count:
> str(AEbySOC)
'data.frame': 19 obs. of 2 variables:
$ SOC : Factor w/ 19 levels "","Blood and lymphatic system disorders",..: 1 2 3 4 5 6 7 8 9 10 ...
$ Count: int 25 50 7 3 1 49 49 2 1 9 ...
One of the levels of SOC is an empty character string:
> l = levels(AEbySOC$SOC)
> l[1]
[1] ""I want to replace the value of this level by a non-empty string, say, "Not specified". This does not work:
> library(plyr)
> revalue(AEbySOC$SOC, c(""="Not specified"))
Error: attempt to use zero-length variable name
Neither does this:
> AEbySOC$SOC[AEbySOC$SOC==""] = "Not specified"
Warning message:
In `[<-.factor`(`*tmp*`, AEbySOC$SOC == "", value = c(NA, 2L, 3L, :
invalid factor level, NA generated
What's the right way to implement this? I appreciate any input/comment.