The documentation/error message could be improved (e.g. setkey could warn when it sees ordered factors) but, currently at least, it's by design. Once floating point and raw character are allowed in keys (progress is happening behind the scenes) hopefully it either goes away, or we could change to cater for ordered factors (which don't have ordered levels) as it wouldn't rely on ordered factor levels.
More background here : http://r.789695.n4.nabble.com/Factors-may-lose-ordered-class-when-used-as-keys-tp3578759p3578759.html and two workarounds here : http://r.789695.n4.nabble.com/Behavior-of-setkey-with-factors-tp2319612p2319612.html -- View this message in context: http://r.789695.n4.nabble.com/key-messes-with-my-factors-tp4058274p4073409.html Sent from the datatable-help mailing list archive at Nabble.com. _______________________________________________ datatable-help mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help
