An event occurs when value(i) is equal to zero.
function [value, terminate, direction] = stopevents(t, y)
value = y(2) - 0.2;
terminate = 1;
direction = 0;
end
The event function must be smooth. It is extremely unlikely, that the integration meets the point y(2)==0.2 exactly. Therefore your event function does not trigger. In addtion:
val = (y(2)==0.2)-0.5;
replies -0.5 or 0.5, but never 0, which would trigger the event.
By the way: Avoid using "dir" as name of a variable, because this shadows an important built-in function.
