Thanks for the droplevels advice, I used it but when I run the below script (with the droplevels), I am having couldnt get parameter "blue" into ert[3], when I run ert, I get the below instead of NA NA "Blue"
[1] NA NA 1
Thanks for any advice.
setup <- data.frame(c("red","blue","green","blue"))
colnames(setup) <- "tester"
red <- data.frame(unique(setup[,"tester"]))
run <- red[2,1]
run <- droplevels(run)
ert <- vector()
ert[3] <- run
ert