Hi, I'm trying to plot bar graphs with stacked columns marked with askterisks for certain columns, which follow certain criteria. I've gotten the stacked bar plots with Data set A (please refer to code below). However, I haven't figured how to put asterisks on columns based on some extra information (such as "used/unused") as in Data set B i.e. asterisks at the top of the Index1 and Index3 columns. ---- R code ---- title = 'frequency' filename = 'testdata2.txt' sample_output = 'sequences' # read in data my.data <- read.delim(filename, sep="\t") # data from second column onward my.dataM <- my.data[,2:ncol(my.data)] # rownames in first column rownames <- my.data[,1] # define colours for the categories col = c ("red ","orange ","yellow ","green ","violet ","cyan","blue","pink","peachpuff","tomato","seagreen","salmon") my.dataNcol <- ncol(my.data[,2:ncol(my.data)]) my.dataColour <- col[1:my.dataNcol] # a bar plot with stacked bars if (is.null(sample_output)) { pdf( "BarPlot.pdf") } else { pdf(file=paste("BarPlot_", sample_output, ".pdf", sep="")) } barplot(as.matrix(my.dataM), main=title, legend=rownames, col=c(my.dataColour) ) dev.off() ------Dataset A: data used with code above------ "" "Index1" "Index2" "Index3" "matched" 0.819 0.174 0.007 "errors" 0.619 0.314 0.067 "unmatched" 0.479 0.385 0.136 ------Dataset B: data intended to use ----- --(last row "used/unused" for determining whether to mark column with asterisk or not)--- "" "Index1" "Index2" "Index3" "matched" 0.819 0.174 0.007 "errors" 0.619 0.314 0.067 "unmatched" 0.479 0.385 0.136 "used/unused" y n y ------- Thanks, Dorothy [[alternative HTML version deleted]]