title: How to show a label from a third data column on mouseover / hover in a Gnuplot scatter plot?
body: <p>I have a gnuplot data file:</p>
  
  <pre><code>Requested_width,Requested_depth,Requested_word,Name,N,M,Cycle_time,Clk2Q,Area,Total_Area
  24,512,24,R1F512X24M8P24,1,1,1.9820,,7446.102,7446
  24,512,24,R1F512X24M4P24,1,1,1.9937,,6757.0596,6757
  ....
  </code></pre>
  
  <p>I want to scatter plot columns 7 and 9 (this I can do!), then I want the name in column 4 to appear when I mouse over a data point. I think it will be too cluttered to have all labels present at all times.</p>