You could plot both histograms into the same file using this: library(lattice) jpeg(filename="combined.jpeg") histogram(~d|f, data = df) dev.off()
Schalk Heunis On Sat, Sep 19, 2009 at 11:37 AM, Sam Player <samtpla...@gmail.com> wrote: > # I have a dataframe with data and factors similar to the following: > > a <- rep(c("a", "b"), c(6,6)) > df <- data.frame(f=a, d=rnorm(12)) > df > > # I am trying to write a 'for' loop which will produce a jpeg histogram for > each factor. I can individually isolate the data from a factor and produce a > jpeg histogram like so: > > fnc <- function(x){ > x <- df[df$f=="a", "d"] > } > > y <- fnc(df[df$f=="a", "d"]) > > jpeg(filename="foo.jpeg") > hist(y) > dev.off() > > # I'm having trouble creating a loop repeating the process for all the > other factors. The following is the best I could come up with. It produces a > single jpeg histogram of the first factor titled with a list of all the > factors. > > a <- rep(c("a", "b"), c(6,6)) > df <- data.frame(f=a, d=rnorm(12)) > df > > for (i in levels(df[,"f"])){ > y <- df[df$f==i, 2] > jpeg(filename=(levels(df[i,"f"]))) > hist(y, main=levels(df[i,"f"])) > dev.off() > } > > # I'm obviously not understanding how loops work with factors. Can anybody > point me in the right direction? > > -- > Sam Player, B.Sc.(Hons.) B.A. > Ph.D. Candidate, Faculty of Agriculture, Food & Natural Resources, > University of Sydney > > Email: spla...@usyd.edu.au > > Agroecosystems Research Group > Room 214 J.R.A. McMillan Building A05 > University of Sydney NSW 2006, Australia > > Angkor Research Program > Room 305 Old Teachers College A22 > University of Sydney NSW 2006, Australia > > ______________________________________________ > 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. > [[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.