Why my code isn't working?

Question

Luis Montenegro 2020-9-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/588706-why-my-code-isn-t-working

评论： Luis Montenegro 2020-9-4

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)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2020-9-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/588706-why-my-code-isn-t-working#answer_489454

在 MATLAB Online 中打开

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

3 个评论
显示 1更早的评论隐藏 1更早的评论

Walter Roberson 2020-9-4

在 MATLAB Online 中打开

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