I am not sure (I can't test at the moment) but will this work? sort(a[,4])
John David Sorkin M.D., Ph.D. Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) >>> nandan amar <nandan.a...@gmail.com> 10/28/2011 10:01 AM >>> I want to sort my following data set according to value in 4th column 0 1 0 27877.3044386212 15.8733019973557 2640.42407064348 0 1 1 27470.1699006254 35.4182473588807 2303.26461260826 0 1 2 27468.0314985496 38.4400363878507 2300.05521684593 0 1 3 27469.1130543141 40.7540672493746 2299.32564458085 0 1 4 27442.3152643187 52.4342875797706 2277.18286686329 0 1 5 27440.7923082136 54.8003481512783 2274.49112409585 ..... I tried following : first i wanted just to sort 4th column >a<-read.tables("file_namr") >attributes(a) gives class as $class [1] "data.frame" and > sort(a[4]) Error in `[.data.frame`(x, order(x, na.last = na.last, decreasing = decreasing)) : undefined columns selected How can I sort the data according to value in 4th column and print along with other columns -- Amar Kumar Nandan Karnataka, India, 560100 ☎:+91-9019054471 ✉:nandan.a...@gmail.com http://aknandan.co.nr [[alternative HTML version deleted]] Confidentiality Statement: This email message, including any attachments, is for th...{{dropped:6}} ______________________________________________ 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.