problem saving pdf file in R with ggplot2

Question

I am encountering an odd problem. I am able to create and save pdf file using R/ggplot2 and view them while the R Console is running. As soon as I exit the R console, Prev

Answer 1

It is in the R FAQ, you need a print() around your call to ggplot() -- and you need to close the plotting device with dev.off() as well, ie try

pdfFile <-c("/Users/adam/mock/dir/structure.pdf")
pdf(pdfFile)
ggplot(y=count,data=allCombined,aes(x=sequenceName,fill=factor(subClass)))
      + geom_bar()
dev.off()

Edit: I was half-right on the dev.off(), apparently the print() isn;t needed. Gavin's answer has more.