Try this: #x <- read.csv('your_file.csv')
x$Col1 <- rep(as.character(x$Col1[x$Col1!="" ]), each = unique(diff(which(x$Col1 != "")))) with(x, sapply(c(sd, mean), function(x)tapply(Col2, Col1, x))) On Thu, Jul 17, 2008 at 12:50 PM, Iain Gallagher <[EMAIL PROTECTED]> wrote: > Hello list > > I have been given some Excel sheets with data laid like this: > > Col1 Col2 > A 3 > 2 > 3 > B 4 > 5 > 4 > C 1 > 4 > 3 > > I was hoping to import this into R as a csv and then get the mean and SD for > each letter in column 1. > > Could someone give me some guidance on best to approach this? > > Thanks > > Iain > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.