Help while using ode45

I am currently trying to solve an ode, and I want to check in each step of the integration if any of the points that i just got as a result of the ode function has crossed a region how do i do that? for instance [1 3] in x and 0 in y, or y<0. In each step of the integration all the points are saved into an array.

Answer 1

[Torsten]

The ballode example should be helpful for your purpose:

http://de.mathworks.com/help/matlab/math/ordinary-differential-equations.html#f1-669698

Best wishes

Torsten.