There is something I do not understand I have a table with columns a,b,c,d,e,z,w
can DT[,list(sum(a+b)),by='z,w'] ever give a different number of lines than DT[,list(sum(a+b),c*d*e),by='z,w'] That's what I am getting !!! -- View this message in context: http://r.789695.n4.nabble.com/AM-I-getting-crazy-tp4687317.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
