Hi statquant3, I found this tutorial very helpful: http://marcoghislanzoni.com/blog/2013/10/11/pivot-tables-in-r-with-melt-and-cast/ Jan -- View this message in context: http://r.789695.n4.nabble.com/learn-how-to-use-melt-and-dcast-tp4690882p4691552.html Sent from the datatable-help mailing list archive at Nabble.com.