Create dummies on R including multiple categories

Question

I need to create a dummy which takes the value 1 if the original variable is equal to 3,4,5 and 0 otherwhise. the original variables is an index rescaled from 1 to 7. I already tried this code:

mediumcivlib<-(as.numeric(civlib==3,4,5)

but it gives me back a dummy with 1 corrisponding to three but not to four and five.

Answer 1

The %in% operator checks whether each number in civlib can be found in the second vector of numbers - c(3, 4, 5) in this case. Wrapping this in as.numeric() converts the output from a logical (True or False) to a numeric output as you wanted.

civlib <- c(1, 2, 3, 4, 5, 6, 7, 3, 4, 5, 2, 3, 4)
as.numeric(civlib %in% c(3, 4, 5))