Look at the apply function ?apply x = data.frame(x1=c(1,2,3,4,5),x2=c(2,4,6,8,10),x3=c(1,3,5,7,9)) x$x5=apply(x,1,mean) x$x6=apply(x,1,sd)
print(x) Abhishek Pratap wrote: > > Hi All > > I have a data frame in which there are 4 columns . > > Column 1 : name > > Column 2-4 : values > > I would like to calculate mean/Standard error of values in column 2-4 and > store them in column 5,6 respectively. > > > > I have done the following but doesn't seem to work > > mean_N_SE <-function(x) > { > > name <- x[1] > vals <- c(x[2:4]) > temp_mean <- mean(vals) > SE <- sqrt(var(x)/length(x)) > > } > > apply(d,1,mean_N_SE) where d = data frame. > > > Can someone help me with this. > > Thanks! > -Abhi > > [[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. > > -- View this message in context: http://n4.nabble.com/Operating-on-each-row-of-data-frame-tp1013365p1013397.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.