Why my code isn't working?

When I try to run the script, an error appears saying "not enough input arguments" and an error in my function, specifically on the T = T0... line and I just can't understand why. Here's my code

function dxdt = funcionVel(t,x)
M = 1200;
r = 0.25;
c = 20;
T0 = 1000;
t0 = 10;

T = T0*(1 - exp(-t/t0));
dxdt(1) = x(2);
dxdt(2) = T/(M*r) - c*x(2);
dxdt = dxdt';

end

%main code 

clear variables
clc

t = (0:0.1:10);
condInicio = [0;0;0];



[T,Y] = ode45(@funcionVel,t,condInicio);
x1 = Y(:,1);
plot(t,x1)

Answer 1

[Walter Roberson]

If you are using a single file then the script has to be before the function. Also, you had too many initial conditions.

t = (0:0.1:10);
condInicio = [0;0];
[T,Y] = ode45(@funcionVel,t,condInicio);
x1 = Y(:,1);
plot(t,x1)

function dxdt = funcionVel(t,x)
M = 1200;
r = 0.25;
c = 20;
T0 = 1000;
t0 = 10;
T = T0*(1 - exp(-t/t0));
dxdt(1) = x(2);
dxdt(2) = T/(M*r) - c*x(2);
dxdt = dxdt';
end

[Luis Montenegro]

Thanks! It worked. Also, if it is not too much to ask, how can I plot x1 for multiple values of M on the same plot?

[Walter Roberson]

t = (0:0.1:10);
condInicio = [0;0];
MVals = [1200 1800 2400];

for M = Mvals
  [T,Y] = ode45(@(t,x) funcionVel(t,x,M), t, condInicio);
  x1 = Y(:,1);
  plot(t, x1, 'DisplayName', sprintf('M = %g', M));
  hold on
end
legend show

function dxdt = funcionVel(t, x, M)
    r = 0.25;
    c = 20;
    T0 = 1000;
    t0 = 10;
    T = T0*(1 - exp(-t/t0));
    dxdt(1) = x(2);
    dxdt(2) = T/(M*r) - c*x(2);
    dxdt = dxdt';
end

[Luis Montenegro]

You really are the mvp!