Dear All, It's Eszter again. Thank you for all, who tried to help me. In this mail I would like to inform you that I could solve my yesterday problem "Error in rowSums(x, prod(dn), p, na.rm) : 'x' must be numeric" only with creating a new datafile. Most probably the problem was that I opened my dataset before in MS Word for editing and MS Word created some transformation with the data which caused R to look at the numbers as strings. If I excluded MS Word from the process, everything was fine. All the best, Eszter _______________________________________________________________________ KGFB 2006 - Garant??ltan a legjobb ??r! Nyerje meg az ??j Swiftet + garant??lt 10,000,- Ft ??rt??k?? aj??nd??k. WWW.NETRISK.HU