thanks for your reply, I have 2 questions about it:
1. is it different from just add empty objects as default to each dataPoint? also no need to delete it
2. as you can see in your solution, Xaxis is changed due to this solution. why its happens?
this is better solution for me, but I still have problem:
Xaxis is Date , I dont know what will be the Date I receive (its realTimeChart, Date can be random),
so lets say I set the dummy data to ‘April 30, 2018’ for ‘series1’ but ‘series2’ getting data with xValue: ‘April 30, 2022’.
it will cause an empty gap betwen ‘April 30, 2018’ – ‘April 30, 2022’