Hi again everyone. I found I could use a list with l = list() l[[1]] = myObj instead of l[1] = myObj Anyone can explain me why the use of double [] is required? Regards, Phil -- View this message in context: http://r.789695.n4.nabble.com/List-or-matrix-of-object-tp2992101p2992121.html Sent from the R help mailing list archive at Nabble.com.