If you are starting with an Excel file, then you should have R read the xls file directly. You should avoid the distortions often introduced by an intermediate format such as .txt or .csv files.
I recommend using RExcel. You can get it from CRAN with install.packages("RExcelInstaller") library(RExcelInstaller) installRExcel() For more details, go to http://rcom.univie.ac.at and click on the Wiki. There are about 5 other packages that are also able to read xls files directly into R. Some of them can read Excel .xls files on operating systems that don't have Excel. Rich ______________________________________________ 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.