Thank you David! That was EXACTLY what I needed. I have one last question:
I want to create a mix of EMU and nonEMU country pairs. I have tried with: EMUmix1<-Reduce(`&`, lapply(countries,function(x,y){country1 %in% euro & country2 %in% noneuro})) # Where euro are the EMU countries and noneuro are (obviously) the nonEMU countries EMUmix2<-Reduce(`&`, lapply(countries,function(x,y) {country1 %in% noneuro & country2 %in% euro})) EMUmix3<-Reduce(`&`, lapply(countries,function(x,y) {country1 %in% euro2 & country2 %in% noneuro})) # euro2 are also the EMUcountries, BUT in 2001 Greece became a EMU member. So in the interval (1999:2000) all euro countries are reprsentated and from 2001- all euro+GREECE=euro2 are representated. EMUmix4<-Reduce(`&`, lapply(countries,function(x,y) {country1 %in% noneuro & country2 %in% euro2})) EMUmixnonGRC<-ifelse(year %in% (1999:2000),EMUmix1|EMUmix2,0) EMUmixGRC<-ifelse(year >= 2001,EMUmix3|EMUmix4,0) EMUmix<- EMUmixnonGRC|EMUmixGRC data2<- cbind(data1,EMUmixnonGRC,EMUmixGRC) # This dosent QUITE work. I get 0 in (1992:1998) and from 2001- there is neither a problem, BUT in (1999:2000) there is a problem: every country pair where Greece (nonEMU at the time) in either country1 list or country 2 is paired with an EMU country I recieve a 0, where I of course seek a 1, hence i am looking for EMUmix Anyone ? ps. thanks to everyone for helping me so far: michael, David, Berend, Rui etc. I know I have a LOT to learn -- View this message in context: http://r.789695.n4.nabble.com/Assignment-problems-tp4578672p4584675.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.