stop Ode45 when y is less than a value

%So thats my ode call and I want it to stop (and save datas % obviously before t=13s) when the value u(1)<=minu
%Where minu is calcuated before.

u0=[vf1m(jj) 0]';
tspan=[0 13]';
Opt    = odeset('Events', @myEvent);
[t,u]= ode45(@(t,u) ok(t,u,p2,m,maxu,maxT), tspan, u0,Opt);

%I tried something like that, nothing worked.
function [value, isterminal, direction] = myEvent(t, u, minu)
value      = u(1)<=minu
isterminal = 1;   % Stop the integration
direction  = 0;

%Eroor Message
Not enough input arguments.
Error in myEvent (line 2)
value      = u(1)<=minu
Error in odeevents (line 28)
  eventValue = feval(eventFcn,t0,y0,eventArgs{:});
Error in ode45 (line 148)
  odeevents(FcnHandlesUsed,odeFcn,t0,y0,options,varargin);
Error in skr (line 217)
[t,u]= ode45(@(t,u) ok(t,u,p2,m,maxu,maxT), tspan, u0,Opt);

[Lazaros Christoforidis]

Note: jj have values so sometimes finishes @13s, other times crashes before

Answer 1

[Torsten]

As defined, ode45 expects myEvent to have 2 input parameters, but you use 3.

Use

Opt = odeset('Events',@(t,u)myEvent(t,u,minu));

And I suggest you set

value = u(1) - minu;

[Lazaros Christoforidis]

Thank you for your answer,

I wanted yo try that but I think its kinda impossible to u(1)==minu.

[Torsten]

It's usual root finding. So why should it be impossible ?

[Lazaros Christoforidis]

Depends the problem,

I have a loop for many gear ratios and I want to find for each ratio If it works or not

My problem is when the u(1): motorcycle engine speed is less or equal than the minimum (minu) the motorcycle needs to stop.

[Steven Lord]

You want your event function to be continuous (as the one Torsten suggested is) rather than discontinuous (like yours that uses <= is.)

The ODE solver will detect when the event function passes through zero.

[Lazaros Christoforidis]

Ohh okay, noww it makes sense

Ευχαριστω, υγεια