ODE 45 Not enough input arguments

It says i don't have enough input agruments in line 3 of the function section and I dont know what is wrong

global m c k Omega f0
k=2000; % N/m
m=5; %kg
c=20; %kg/s
dt=0.005;
f0=37.5;
Omega= 25;
t=0:dt:5;
x0=[0 0];
function rl=f(t,y)
    global m c k Omega f0
    f=f0*sin(2*pi*Omega*t);
    rl=[y(1); f/m-(c*y(1))/m-k*y(2)/(4*m)];
end

[James Tursa]

Where is the rest of your code? Where is the ode45( ) call?

[Jan]

The cause of the problem would be clear, if you post the complete code including the call to ODE45 and a copy of the complete error message.

[Mauricio San Román Caraza]

I had the function and the rest of the code as two separate files. The error only appeared in the function file, this is why I didn't post the rest of the code. However when I combined them into a single file the problem appears to be gone, but the complete code and error that displayed was this:

clc;close all; clear;

global m c k Omega f0

k=500; % N/m

m=5; %kg

c=20; %kg/s

dt=0.005;

f0=37.5;

Omega= 25;

t=0:dt:5;

x0=[0 0];

[t,y]=ode45(@(t,y)f(t,y),t,x0);

plot(t,y(:,1))

--------------------------------------------------------------------------------

function rl=f(t,y)

global m c k Omega f0

f1=f0*sin(Omega*t);

rl=[y(2);(f1-c*y(2)-k*y(1)/4)/m];

end

Error in f (line 3)

f1=f0*sin(Omega*t);

[Jan]

As far as I understand, your problem is solved. But it may help to improve future questions: You have still not posted a complete copy of the error message, but just the part, which explains where the problem occurred.

Answer 1

[Jan]

We cannot see it, because you have not posted the complete code. But this has been the reason in many other questions in this forum:

[t, y] = ode45(rl, ...)

This calls rl without inputs. You want to provide the handle of the function instead:

[t, y] = ode45(@rl, ...)