a little bit wrong lets find it

[ptc-4993095]

[Werner_E · Accepted solution]

The number of intervals (100 in your case) must be greater or equal than the length of the interval to be solved for (1000-0=1000 in your case).

I think you wanted to see the solution up to 100 with 1000 intervals:

[ptc-4993095]

may ı real simulate this work with moving things