> >> >as.numeric(assame$Login) //convert to numerics >> > > > NOOOOooooooo. You did not do what what I suggested earlier. Do not reach > for your keyboard in the R console until you have read the FAQ section > regarding converting factors to numeric. If you don't want to read the FAQ
Hi David, Now I understand the trick : as.numeric(as.character(Login)) > avglog <- with(assame,tapply(as.numeric(as.character(Login)),stdate,mean))> > avglog 01/11/09 00:00 02/11/09 00:00 04/11/09 00:00 05/11/09 00:00 06/11/09 00:00 22.04866 16.65358 15.84970 16.58600 16.20743 07/11/09 00:00 18.52379 But still it will not work : > avglog <- with(assame,tapply(as.numeric(levels(Login)[as.integer(Login)]),stdate,mean)) Error in tapply(as.numeric(levels(Login)[as.integer(Login)]), stdate, : arguments must have same length Thanks & Rg Mohan L [[alternative HTML version deleted]] ______________________________________________ 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.