Situation is described here : 
http://stackoverflow.com/questions/16262065/take-only-some-value-from-javafx-observablelist
We have already an array of user data items, and we need to create another array, which will contain items of XYChart.Data type. Instead of this I suggest to give possibility to put the initial array and a factory, which, for each user data instance suggest an instance of XYChart.Data object. And chart will track changes of the intial list, and call factory for newly added items, where needed.
http://stackoverflow.com/questions/16262065/take-only-some-value-from-javafx-observablelist
We have already an array of user data items, and we need to create another array, which will contain items of XYChart.Data type. Instead of this I suggest to give possibility to put the initial array and a factory, which, for each user data instance suggest an instance of XYChart.Data object. And chart will track changes of the intial list, and call factory for newly added items, where needed.
 P4
  P4