Not quite what you asked for but would this do? library(plyr) x <- as.factor(c(1,1,1,2,2,2,3,3,3)) y <- as.factor(c(10,10,10,20,20,20,30,30,30)) z <- c(100,100,NA,200,200,200,300,300,300) df1 <- data.frame(x, y, z)
(dsum <- ddply(df1, .(x, y), summarise, sum = sum(z, na.rm = TRUE), mean = mean(z, na.rm = TRUE), count = length(z))) John Kane Kingston ON Canada > -----Original Message----- > From: viora...@gmail.com > Sent: Fri, 20 Jul 2012 03:30:16 -0700 (PDT) > To: r-help@r-project.org > Subject: [R] Crosstab with Average and Count > > I have the following data: > > x <- as.factor(c(1,1,1,2,2,2,3,3,3)) > y <- as.factor(c(10,10,10,20,20,20,30,30,30)) > z <- c(100,100,NA,200,200,200,300,300,300) > > I could create the cross tab of x and y with Sum of z as its elements > using > the xtabs function as follows: > > # X Vs. Y with Sum Z > > xtabs(z ~ x + y) > > y > x 10 20 30 > 1 200 0 0 > 2 0 600 0 > 3 0 0 900 > > How do I replace the sum with average and count so that I can get the > following outputs?? > > # X Vs. Y with Average of Z > y > x 10 20 30 > 1 100 0 0 > 2 0 200 0 > 3 0 0 300 > > # X Vs. Y with Count Z > y > x 10 20 30 > 1 2 0 0 > 2 0 3 0 > 3 0 0 3 > > Would appreciate any help on these? Thank you. > > Ravi > > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Crosstab-with-Average-and-Count-tp4637180.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. ____________________________________________________________ GET FREE SMILEYS FOR YOUR IM & EMAIL - Learn more at http://www.inbox.com/smileys Works with AIM®, MSN® Messenger, Yahoo!® Messenger, ICQ®, Google Talk™ and most webmails ______________________________________________ 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.