> i am wondering whether there is a special need to "clean up" txt > files > that were created in windows or Excel before using them in R. > if so, how would you clean them? There are special package "foreign" which allows to read external data (such as xls). As for txt files (tab-delimited (?)), they could be read with read.table. If the file was created in Windows environment there could be problem with end of the line character (which are different in Win and Unix). I solve that just replacing "\r" and "\n" with "$" in bash (sed). HTH -- Maciej Jonczyk, Department of Plant Molecular Ecophysiology Faculty of Biology, University of Warsaw 02-096 Warsaw, Miecznikowa 1 Poland -- This email was Anti Virus checked by Astaro Security Gateway. http://www.astaro.com