Not enough input arguments ode45

10 次查看（过去 30 天）
Vipin Padinjarath
Vipin Padinjarath 2016-10-6
编辑： Vipin Padinjarath 2016-10-6
Hi all, I have been trying to understand the use of ode solvers in MATLAB. In the process, I started with first order equations and all went well. The moment I started trying out second order systems, the trouble started. When I run the code, it shows 'not enough input arguments'. I thought that it may the problem with my code and then I started trying codes given as example in text books (Otto&Denier etc.). For every code, every time I run, the same issue pops up. And the code seems to be correct. Please help me to sort it out. I have attached the screenshot of the error message.
">> lorenz Error using lorenz (line 5) Not enough input arguments." This was a code I chose from a text book.
if true
% code
function dx=lorenz(t,x)
sigma=10;
rho=28;
beta=8/3;
dx=[sigma*(x(2)-x(1));x(1)*(rho-x(3)-x(2));x(1)*x(2)-beta*x(3)];
x0=[0 1 1.05];
tspan=[0,20];
[t,x]=ode45(@lorenz,tspan,x0);
plot(x(:,1),x(:,3))
end

请先登录，再回答此问题。

采纳的回答

Massimo Zanetti
Massimo Zanetti 2016-10-6
Separate the funciton from the rest
function dx=lorenz(t,x)
sigma=10;
rho=28;
beta=8/3;
dx=[sigma*(x(2)-x(1));x(1)*(rho-x(3)-x(2));x(1)*x(2)-beta*x(3)];
end
and invoke ode45 correctly
x0=[0 1 1.05];
tspan=[0,20];
[t,x]=ode45(@(t,x) lorenz(t,x),tspan,x0);
plot(x(:,1),x(:,3))
Does it work now?
  4 个评论
显示 2更早的评论
Vipin Padinjarath
Vipin Padinjarath 2016-10-6
Yes! It is running now.Thank you very much.
Vipin Padinjarath
Vipin Padinjarath 2016-10-6
编辑：Vipin Padinjarath 2016-10-6
I am sorry, I know that I am troubling you. But please help me with the following code. This i wrote by myself. (Rossler equations)
Function definition
if true
% function dR=RH(t,x,y,z)
dR=zeros(3,1);
dR(1)=-(y+z);
dR(2)=(x+2*y);
dR(3)=(1+z(x-3));
end
end
Solution
if true
s0=[1 1 1];
tspan=[0 50];
[t,x,y,z]=ode45(@(t,x,y,z)RH(t,x,y,z),tspan,s0);
plot3(t,x,y,z)
end

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Ordinary Differential Equations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by