MATLAB event function help
显示 更早的评论
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?
采纳的回答
Torsten
2018-8-29
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
更多回答（2 个）
Walter Roberson
2018-8-29
tRange = [0 3];
Y0 = [0 20];
options = odeset('Events',@event_function);
[tSol,YSol,te,ye,ie] = ode45(@myode,tRange,Y0,options);
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
function [value,isterminal,direction] = event_function(t,Y)
value = (Y(1) ~= 0);
isterminal = 1;
direction = 0;
end
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