I'm not sure how else to describe this problem. I hope someone knows of this issue already.
Reprex:
t_fac <- factor(c("A", "A"))
t_lev <- factor(c("B", "C"))
t_lab <- c(1, 1)
factor(t_fac, levels = t_lev, labels = t_lab)
Returns:
[1] <NA> <NA>
Levels: 1
Where I would expect:
[1] 1 1
Levels: 1
How to get expected result? Any ideas are welcome.
Reading from the help page for factor, levels is "an optional vector of the unique values (as character strings) that x might have taken". You have the value "A" in your data vector (t_fac), but you include only "B" and "C" as levels.
I think you can adjust this simply by including "A" as a possible level:
t_fac <- c("A", "A")
t_lev <- c("A", "B") # "A" needs to be here
t_lab <- c(1, 1)
factor(t_fac, levels = t_lev, labels = t_lab)
[1] 1 1
Levels: 1
If you want to have "A", "B", and "C" as possible levels, you will need to add a 1 in the labels vector:
t_fac <- c("A", "A")
t_lev <- c("A", "B", "C")
t_lab <- c(1, 1, 1)
factor(t_fac, levels = t_lev, labels = t_lab)