Hi @Madeleine
To stop at the third x-axis crossing, you need to count the number of crossings and stop when the count reaches three. You can achieve this by using a "persistent" variable to keep track of the number of crossings that have occurred.
Here's how you can modify your function:
function [value, isterminal, direction] = xcross(t, state_xyz, mu)
persistent crossing_count;
if isempty(crossing_count)
crossing_count = 0;
end
v1 = state_xyz(2);
v2 = state_xyz(5);
value = v1;
direction = 0;
% Check if it's a crossing
if v1 == 0 && v2 > 0
crossing_count = crossing_count + 1;
end
% Stop at the third crossing
if crossing_count == 3
isterminal = 1;
else
isterminal = 0;
end
end
Hope this helps!
