Nested ifelse statement

Question

I\'m still learning how to translate a SAS code into R and I get warnings. I need to understand where I\'m making mistakes. What I want to do is create a variable which summ

Answer 1

With data.table, the solutions is:

DT[, idnat2 := ifelse(idbp %in% "foreign", "foreign", 
        ifelse(idbp %in% c("colony", "overseas"), "overseas", "mainland" ))]

The ifelse is vectorized. The if-else is not. Here, DT is:

    idnat     idbp
1  french mainland
2  french   colony
3  french overseas
4 foreign  foreign

This gives:

   idnat     idbp   idnat2
1:  french mainland mainland
2:  french   colony overseas
3:  french overseas overseas
4: foreign  foreign  foreign