Error report when using ode45 function

The following errors occurred in solving the tripartite evolutionary game,does anyone know the reason?
Here is the error.
索引超出矩阵维度。
出错 differential (line 2)
dxdt=[x(1)*(1-x(1))*(10-3*x(3)-5*x(2));x(2)*(1-x(2))*(4*x(1)+12.6*x(3)-9);
出错 odearguments (line 87)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.
出错 ode45 (line 115)
odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
出错 run (line 5)
[T,Y]=ode45(@differential,[0,20],[i j m]);
The code is as follows.
function dxdt=differential(x,t)
dxdt=[x(1)*(1-x(1))*(10-3*x(3)-5*x(2));x(2)*(1-x(2))*(4*x(1)+12.6*x(3)-9);
x(3)*(1-x(3))*(3*x(1)*x(2)+20.4*x(2))]
%t是演化的步长和时间
end
--------------------------------------
clear all
for i=0.1:0.2:0.9
for j=0.1:0.2:0.9
for m=0.1:0.2:0.9
[T,Y]=ode45(@differential,[0,20],[i j m]);
figure(1)
grid on
plot(T,Y(:,1),'r-','lineWidth',1);
hold on
plot(T,Y(:,2),'b--','lineWidth',1);
hold on
plot(T,Y(:,3),'g*','lineWidth',1);
hold on
end
end
end

2 commentaires

James Tursa
James Tursa le 20 Fév 2021
Please delete these images and instead post your code and error messages as text highlighted with the CODE button. We can't copy & run pictures.
Erin Sausage
Erin Sausage le 21 Fév 2021
Oh thanks for reminding me. I re-edit the post as you say, if possible, could you plz help me to see why such the error occurs?

Connectez-vous pour commenter.

 Réponse acceptée

Walter Roberson
Walter Roberson le 21 Fév 2021
function dxdt=differential(x,t)
needs to be
function dxdt=differential(t,x)

3 commentaires

Erin Sausage
Erin Sausage le 21 Fév 2021
oh I got it! Thanks you! But why my teacher can run with such code, mine can't? Is it because of the different versions?
No, versions would not have anything to do with it. The code was just wrong. In order to use that function the way it was, you would need to use
[T,Y]=ode45(@(t,x)differential(x,t), [0,20], [i j m]);
Erin Sausage
Erin Sausage le 21 Fév 2021
I see. I'm so greatful for your reply!

Connectez-vous pour commenter.

Plus de réponses (0)

Catégories

En savoir plus sur Number games dans Centre d'aide et File Exchange

Community Treasure Hunt

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

Start Hunting!

Translated by