title: Simple flot graph not updating
body: <p>I'm trying to create a simple flot line graph and update it on a timer and I only want to display the last 10 points of data. But I only ever see the axis and not the graph plot. Also, I see the x axis change with the extra data but the y axis remain the same and do not correspond to the additional data. My code is as following:</p>
  
  <pre><code>var dataSet = [];
  var PlotData;
  var x = 0;
  var y = 0;
  var plot = null;
  
  function EveryOneSec()
  {
      if (dataSet.length == 10)
      {
          dataSet.shift();
      }
      x++;
      y += 2;
      dataSet("[" + x + ", " + y + "]");
  
      PlotData = { label: "line 1", data: [ dataSet ], color: "green" };
  
      if (plot == null)
      {
          plot = $.plot($("#placeholder"), [ PlotData ], { lines: {show: true}, points:          {show: true}});
      }
      else
      {
          plot.setData([ PlotData ]);
          plot.setupGrid();
          plot.draw();
      }
      setTimeout(EveryOneSec, 1000);
  }
  </code></pre>
  
  <p>I have tried with and without the call to setupGrid() but this makes no difference to the axis display or graph plot. The x axis stop changing when I get the ticks 0 to 9 plotted even though x is incrementing past that, and the y axis remains static. I believe the code is correct above in terms of passing arrays of data, so why is the graph not appearing?</p>