It's simpler to use the "rug" function.... On 11/1/2011 11:11 AM, Janet L Smith wrote: > Set the y-axis on your histogram to start at a negative value, then use segments to draw the lines. > > hist (your_data, ylim=c(-10,100)) > segments (15,-0, 15, -20, col="red") > > > Janet Smith > Research Scientist > Department of Biology > MIT > Building 68-540D > Cambridge, MA 02139 > ________________________________________ > From: bioconductor-bounces at r-project.org [bioconductor-bounces at r-project.org] On Behalf Of Wendy Qiao [wendy2.qiao at gmail.com] > Sent: Tuesday, November 01, 2011 12:01 PM > To: bioconductor at r-project.org > Subject: [BioC] annotate histograms > > Hi all, > > I am plot the gene expression data using histograms. I want to mark the > expression of certain level of certain genes on the figure as shown in sure > here<http: nar.oxfordjournals.org="" content="" 39="" suppl_1="" d1011="" f1.expan="" sion.html="">. > Does anybody know how to add the red markers under bars. > > Thank you in advance. > > Wendy > > [[alternative HTML version deleted]] > > _______________________________________________ > Bioconductor mailing list > Bioconductor at r-project.org > https://stat.ethz.ch/mailman/listinfo/bioconductor > Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor > > _______________________________________________ > Bioconductor mailing list > Bioconductor at r-project.org > https://stat.ethz.ch/mailman/listinfo/bioconductor > Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor