MATLAB: MATLAB event function help

matlab function

Hi, new to matlab and doing the academy courses to help, running through the ODE course and coming to an example where they suggest adding an event function to stop the calculation when a projectile hits the ground.
Its a series of 2 odes and its a simple code:
tRange = [0 3];
Y0 = [0 20];
[tSol,YSol] = ode45(@myode,tRange,Y0)
h = YSol(:,1)
plot(tSol,h)
function dYdt = myode(t,Y)
h = Y(1);
u=Y(2);
dhdt = u;
dudt = -9.8;
dYdt = [dhdt;dudt];
end
from the event function page I think you are supposed to set it up as:
options = odeset('Events',@event_function)
[tSol,YSol,te,ye,ie] =(@myode,tRange,Y0,options)
function [value,isterminal,direction] = event_function(t,h)
value = (Y(1) ~= 0); 
isterminal = 1; 
direction = 0;
but get a load of errors, what am I doing wrong?

Best Answer

function main
tRange = [0 10];
Y0 = [0 20];
options = odeset('Events',@event_function)
[tSol,YSol,te,ye,ie] =ode45(@myode,tRange,Y0,options)
h = YSol(:,1);
plot(tSol,h)
end
function [value,isterminal,direction] = event_function(t,h)
value = h(1); 
isterminal = 1; 
direction = 0;
end
function dYdt = myode(t,Y)
h = Y(1);
u=Y(2);
dhdt = u;
dudt = -9.8;
dYdt = [dhdt;dudt];
end
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