Here is how I usually do this: # (1) Create and plot some sample data bar <- barplot(x <- abs(rnorm(10,2,1)), names.arg = letters[1:10], col="red", ylim=c(0,5)) stdev <- x/5 # (2) Add error bars arrows(bar, x, bar, x + stdev, length=0.15, angle = 90) arrows(bar, x, bar, x + -(stdev), length=0.15, angle = 90) Thomas On Mon 11/20/06 20:05, Matthias Kohl wrote: > Hello, > > function plotCI in package gplots or function plotCI in package plotrix > might do what you want. > > hth > Matthias > > > Jianping Jin schrieb: > > Dear list, > > > > Does any one know how to add SD information of a data set onto a plot which > > displays mean values for each group? I did something like: > > > > > >> x = c(0,1,2,3) > >> y = apply(data,2,mean) > >> plot(x,y) > >> > > > > Thanks for you help! > > > > Jianping > > > > ################################## > > Jianping Jin Ph.D. > > Bioinformatics scientist > > Center for Bioinformatics > > Room 3133 Bioinformatics building > > CB# 7104 > > University of Chapel Hill > > Chapel Hill, NC 27599 > > Phone: (919)843-6105 > > FAX: (919)843-3103 > > E-Mail: jjin at email.unc.edu > > > > _______________________________________________ > > Bioconductor mailing list > > Bioconductor at stat.math.ethz.ch > > https://stat.ethz.ch/mailman/listinfo/bioconductor > > Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor > > > > > -- > Dr. rer. nat. Matthias Kohl > E-Mail: matthias.kohl at stamats.de > Home: www.stamats.de > > _______________________________________________ > Bioconductor mailing list > Bioconductor at stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/bioconductor > Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor > -- Thomas Girke, Ph.D. 1008 Noel T. Keen Hall Center for Plant Cell Biology (CEPCEB) University of California Riverside, CA 92521 E-mail: thomas.girke at ucr.edu Website: http://faculty.ucr.edu/~tgirke Ph: 951-827-2469 Fax: 951-827-4437