Hello All, Many thanks to the help I have received so far.
Here is an example data set I hope to plot Data1 Year Data SE 1 2005 2 0.01 2 2006 4 0.01 3 2007 5 0.01 4 2008 2 0.01 5 2009 3 0.01 6 2010 6 0.01 Data2 Year Data SE 1 2006 32 1 2 2007 100 2 3 2008 60 4 4 2009 67 3 5 2010 8 1 Notice Data2 has one less years worth of data than Data1 (which is my problem) I am fond of using plotCI as it makes creating error bars and offsetting overlapping error bars so easy, and double y-axis plots are a breeze library(plotrix) library(gplots) offset=.08 plotCI(x=Data1$Year, y=Data1$Data, uiw=Data1$SE,lty=1,sfrac=.005, type="l", gap=0, col="red", xlab="YEAR") par(new=TRUE) plotCI(x=(Data2$Year) +offset, y=Data2$Data, uiw=Data2$SE,lty=1,sfrac=.005, type="l", gap=0, col="blue", xaxt="n",yaxt="n",xlab="",ylab="") axis(4) This above code is sooo close to what I want. It creates a plot where even though one data set contains much larger numbers than the other, both fit on the same plot without me having to manually adjust the Y axis. And the generating the second Y-axis is simple. But my problem is with the x axis The issue is that because the two Data sets are not the same size, the Data2 line gets stretched along the x-axis in the plot to cover the missing first year. So it looks like Data2 has data in 2005. I can't plot the Data2 line by the year in Data1 aka ( plotCI((x=(Data1$Year) +offset, y=Data2$Data.......) because the data are not of equal size I was thinking something along the line of pulling out the matching years such as ( plotCI(x=(Data1[c(2:6),1])+offset, y=Data2$Data.......) but I could not get it to work. Any suggestions will earn you well earned programing karma and many thanks from me. Cheers [[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.