             "red")
          .attr("stroke", "black")
          .attr("stroke-width", "2")
+         .on("mouseover", efftip)
+         .on("mouseout", -> d3.selectAll("#efftip").remove())
 
 
   # background rectangles for each chromosome, alternate color


  # Using https://github.com/Caged/d3-tip
  #   [slightly modified in https://github.com/kbroman/d3-tip]
  tip = d3.svg.tip()
          .orient("right")
          .padding(3)
          .text((z) -> z)
          .attr("class", "d3-tip")
          .attr("id", "d3tip")

  markerClick = []


               g = data.geno[marker][i]
               return "2" if g < 0
               "1")
          .on("mouseover", indtip)
          .on("mouseout", -> d3.selectAll("#indtip").remove())


  # function to revise phenotype vs genotype plot
  revPXG = (chr, marker) ->
