On Wed, Apr 29, 2009 at 01:58:06PM +0530, Umesh Srinivasan wrote: > Hi all, > > If I have a huge matrix/ dataframe and I want to create a new matrix/ > dataframe with every second (or third, or fourth etc.) row of the original > matrix, how can I do it? Any help much appreciated.
Others ahve already poitned out soltions using seq9(). I'd just like to add an alternative approach making use of R's logical indexing and recycling rules: mat <- matrix(1:1000, 100, 5) mat2 <- mat[c(T,F),] cu Philipp -- Dr. Philipp Pagel Lehrstuhl für Genomorientierte Bioinformatik Technische Universität München Wissenschaftszentrum Weihenstephan 85350 Freising, Germany http://mips.gsf.de/staff/pagel ______________________________________________ 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.