Problem with my non linear pendulum code

Hi, i need to solve the differential equation of my pendulum, but when i type my code, Matlab marks me a problem in my M-file. Hope you can help me, please!

m-file
function dudt=pendulum (t,u)
w=10;
dudt(1,:) = u(2);
dudt(2,:) = -w*sin(u(1));
end

The code is the netx one

tspan=[0,2*pi];
u0=[pi/4;0];
[t,u]=ode45(@pendulum,tspan,u0,[]);
plot(t,u(:,1),'b-', 'Line Width', 2)
xlabel('time')
ylabel('angle')

Answer 1

[Star Strider]

Eliminate the space:

plot(t,u(:,1),'b-', 'Line Width', 2)
                         ↑ ← HERE              

It should be:

plot(t,u(:,1),'b-', 'LineWidth', 2)

That willl work.

[Carlos Gerardo Rodríguez González]

It works, thank you very much!!

[Star Strider]

As always, my pleasure!

[KLETECH MOTORSPORTS]

[KLETECH MOTORSPORTS]

i got ^ error when i ran the code

Answer 2

[John D'Errico]

Why do you think there is a problem? The code runs fine.

Are you worried that the editor tells you that essentially, t is not used as a variable? That is just a warning, in case you have made a mistake.

Is that the correct sytem of ODEs? If so, then there is no problem.

[Carlos Gerardo Rodríguez González]

Hi, yes, when i type my m-file, Matlab signs me this problems, i can't put the two variables in my ODE

[Carlos Gerardo Rodríguez González]

Sorry, ma mistake, it works, i restart my pc and works, thank you for your suppor!