Dear friends, my question is how to aggregate dataset and the inverse manipulation. e.g.My dataset data structure1: x 1 1 2 3 3 data structure2: x freq 1 2 2 1 3 2 Then how to generate dataset2 from dataset1 and generate dataset1 from dataset2? e.g. dataset2 from dataset1 : x<-c(1,1,2,3,3) a<-tab(x) as.data.frame(a) *But i can't do the inverse manipulation:generate dataset1 from dataset2*, anybody can help me on the two different manipulations? Thanks a lot! -- Kind Regards, Zhi Jie,Zhang ,PHD Department of Epidemiology School of Public Health Fudan University Tel:86-21-54237149 [[alternative HTML version deleted]]
data.frame(x = with(df1, rep(x, freq))) ------------------------------------------------------------------- Jacques VESLOT CNRS UMR 8090 I.B.L (2?me ?tage) 1 rue du Professeur Calmette B.P. 245 59019 Lille Cedex Tel : 33 (0)3.20.87.10.44 Fax : 33 (0)3.20.87.10.31 http://www-good.ibl.fr ------------------------------------------------------------------- zhijie zhang a ?crit :> Dear friends, > my question is how to aggregate dataset and the inverse manipulation. > e.g.My dataset > data structure1: > x > 1 > 1 > 2 > 3 > 3 > data structure2: > x freq > 1 2 > 2 1 > 3 2 > Then how to generate dataset2 from dataset1 and generate dataset1 from > dataset2? > > e.g. dataset2 from dataset1 : > x<-c(1,1,2,3,3) > a<-tab(x) > as.data.frame(a) > > *But i can't do the inverse manipulation:generate dataset1 from dataset2*, > anybody can help me on the two different manipulations? > > Thanks a lot! > > > > >