Sorry, but we are not able to understand the issue clearly. Can you please explain it in detail.
When you say “of 250 but I change it to 100” do you mean changing the range programmatically (via minimum and maximum) by zooming in to the region manually with mouse/pointer.
What other parameters are you changing?
And what do you mean by clearing the excess data? Are you looking for dynamic charts like this by any chance?
Can you please give us step by step instructions to reproduce the problem??