title: different Tick Unit (interval) in Number Axis based on density of data points in jFreeChart
body: <p>I want to show the result of my simulation with XYLineChart of JfreeChart, the range of Number Axis is between time =0 to time =3000, but the density of data points are different in different time intervals, </p>
  
  <p>for example there is just few data points until time 1000, then the density in time interval (1000 - 2000 ) is too high, and again i have few data points in time interval (2000 -3000)
  so, i want to have different tick unit automatically based on the density of the data points,
  the only code i use is:</p>
  
  <p>NumberAxis xAxis = (NumberAxis) plot.getDomainAxis();</p>
  
  <p>xAxis.setAutoRange(true);</p>
  
  <p>xAxis.setAutoTickUnitSelection(true);</p>
  
  <p>it must be done automatically, because, the data points are generated during my simulation, and i don't know in which interval the density is high or low</p>