Dear all, I have a data frame that looks like this: c1 c2 c3 A B C B C A A A B and so on; I´d like to produce one single vector consisting of the columns c1,c2, c3, such that vector=("A","B","A","B","C","A","C","A","B") I guess it´s easy to do but I don´t know how...Can anyone help me? Thanks a lot! Christoph