Hello Doug, I just wanted to add that a faster way to initialize a vector is:
avg <- vector("numeric", nrow(d)) Also you might like nrow(d) over length(d[ , 1]) if the number of rows is what you are after. Its sister function is ncol() . Best regards, Josh On Mon, Jun 28, 2010 at 11:37 AM, Douglas M. Hultstrand <dmhul...@metstat.com> wrote: > Hello, > > I am trying to calculate the mean value of each row in a data frame (d), I > am having troubles and getting errors using the code I have written. Below > is a brief example of the code, any thought or suggestions would be great. > > Thank you for your time, > Doug > > > # Example Code: > d <- data.frame(st1=c(1,2,3,4), st2=c(2,5,6,7), st3=c(5,5,NA,7), > st4=c(6,5,7,8)) > avg <- rep(NA,length(d[,1])) > > for (i in 1:length(d[,1])) { > avg[i] = mean(d[i,1:4], na.rm=TRUE) > } > > # Final Output wanted. > st1 st2 st3 st4 avg > 1 1 2 5 6 3.50 > 2 2 5 5 5 4.25 > 3 3 6 NA 7 5.33 > 4 4 7 7 8 6.50 > > -- > --------------------------------- > Douglas M. Hultstrand, MS > Senior Hydrometeorologist > Metstat, Inc. Windsor, Colorado > voice: 720.771.5840 > email: dmhul...@metstat.com > web: http://www.metstat.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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.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.