Hi > EMU1993<-(for (i in 1:nrow(data)){ + ifelse(year==1992,sum(avgflowEMU),0) + }) >EMU1993 NULL -- View this message in context: http://r.789695.n4.nabble.com/Assignment-problems-tp4578672p4581590.html Sent from the R help mailing list archive at Nabble.com.