You might try 'bargraph.CI' in R pkg 'sciplot'. ?bargraph.CI
HTH, Savi >>> Anna Harris <annaharrisish...@hotmail.com> 6/15/2011 1:00 PM >>> Hi, Can anyone help with plotting vertical error bars on a bar graph. I have tried following examples online and in the big R book and writing my own function but I have been unsuccessful and don’t really have an understanding of what it is I am doing. I have calculated my standard errors so basically just need to draw the bars on the graph but just don’t have a clue!!! I don’t even know what information people will need to help me...... The code for my graph is: barplot(tapply(Sporangia,list(Host,Isolate),mean),xlab="Isolate",ylab="Mean Sporangia per Needle",col=c("grey39","grey64","grey89"),beside=T) col=c("grey39","grey64","grey89") legend("topright",inset=.05,title="Host",c("European Larch","Hybrid Larch","Japanese Larch"),fill=col,horiz=FALSE) Any help would be greatly appreciated, Anna [[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.