thanks for your reply but I don't think your solution can accomplish to what I need... (I can't see any ordering of the variable "sample" with reference to the variable "obs")
please keep in mind that for a numer of reasons that I do not mention here for the sake of conciseness in my case the variable "sample" must be espressed as a charachter (because what I proposed here is a simplification of the original variable composed by a concatenation of more information strings than the sampling date itself) and finally the labels on y axis are still not correctly disposed : same problem as in my example (also this feature must be properly sorted out) I think it's necessary to stick on the reordering of varibles but I can't figure how jet... m -- View this message in context: http://r.789695.n4.nabble.com/Reordering-levels-of-a-factor-within-a-lattice-dotplot-tp4634201p4634220.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.