Just plotting the mean is not very informative (at least not more informative than providing the same information in a table). If you want to show some of the distributional properties of height for each Age_group x City pair, try box-and-whisker plots ?bwplot
Imagine you have four age categories and five cities. Age=rep(0:3,each=25) City=rep(0:4,20) e=rnorm(100) #Create a dependent variable Height=(Age-1)+(City-1)+(Age-1)*(City-1)+e #Box whisker plot of Height by Age category for each City bwplot(Height~factor(Age)|factor(City)) Daniel ------------------------- cuncta stricte discussurus ------------------------- -----Ursprüngliche Nachricht----- Von: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] Im Auftrag von w_poet Gesendet: Tuesday, August 25, 2009 1:17 PM An: r-help@r-project.org Betreff: [R] table, xyplot, names, & loops Hi R community, I'm just starting out in R and have a basic question about xyplot and tables. Suppose I had a table of data with the following names: Height, Age_group, City. I'd like to plot mean Height vs Age_group for each City. When I try to do the following: > library(lattice) > xyplot(mean(Height) ~ Age_group | City) of course I get just one data point, the mean Height for all individuals. I also tried constructing a new array with mean Height for each Age_group, factored by City, but couldn't find any way of doing this without using loops. I'm sure there must be an elegant way of plotting this in R without resorting to loops, but I can't find any hints in the online manuals. Thanks for any tips~ -- View this message in context: http://www.nabble.com/table%2C-xyplot%2C-names%2C---loops-tp25138552p2513855 2.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. ______________________________________________ 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.