Argument “No” is missing, with no default

Question

I need to assign values in the variable \"TRTCD1\" in two different classes as 1 and 2, based on the condition as stated in the R programming code below.

z$T         


        

Answer 1

My guess is as following.

ifelse(TRTCD1 == 0 & TRTCD1 == 40,
       1,
       ifelse(TRTCD1 >= 10 & TRTCD1 <= 30 & TRTCD1 == 50, 2, *value if NO*)
)

Only the case where the second ifelse is TRUE is given.