2 Replies Latest reply on Dec 21, 2012 3:09 PM by Jonathan Drummey

    Marking Overlap Between two Data Points

    Mike J



      I'm looking to create a line chart where you mark the overlap between data points.

      I'm not sure how to create this in tableau, I've attached a sample graph.

      Thanks for the help.


      (Please Note: I'm plotting a time series not "issue 1.." as the sample image suggests.)



        • 1. Re: Marking Overlap Between two Data Points
          Catherine Rivier

          Hi Mark,

          I've been trying a few different things with this, but I can't really think of a workaround on this that does exactly what you want.  The problem is there's really no way to get an area chart to start at a place other than 0, which is what this is doing.


          However, there are two alternates that might work for you.  See the attached workbook.  The first is a simple area chart, with a line chart overlaid (so the lines are absolutely clear).  You could play around with the coloring to get the best combo for your needs.


          The second/third charts are Gantt Bars, which can look like bar charts that start at a value other than 0.  To do this, I created a few calculated fields (all of the calculated Measures named "Sales__").  I basically calculated all of these to find the starting values, color criteria, and differences for every month shown.  Then in the second sheet, I overlaid a line chart, which is, I suppose, the closest to what you have above that I could get.


          I hope this helps a little, though perhaps someone else will have a different solution!

          • 2. Re: Marking Overlap Between two Data Points
            Jonathan Drummey

            See this thread from the spring: http://community.tableau.com/message/175980?tstart=0. It didn't have different shading depending on which measure was higher, but I think there's enough there to get you started.