Thank for all your answer ! Here is another way I discoverd this morning : barplot(table(factor(variable, levels = 1:4)),names=c(1,2,3,4)) -- View this message in context: http://r.789695.n4.nabble.com/barplot-with-some-0-frequencies-tp4645102p4645208.html Sent from the R help mailing list archive at Nabble.com.