ode45 for third order differential
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
I am trying to solve a third order differential equation by representing it as a set of first order diff equations. The constants are user input arguments.
A=str2double(get(handles.Avalue, 'string'));
B=str2double(get(handles.Bvalue, 'string'));
C=str2double(get(handles.Cvalue, 'string'));
E=str2double(get(handles.Evalue, 'string'));
F=str2double(get(handles.Fvalue, 'string'));
t=str2double(get(handles.tvalue, 'string'));
xinitial=0;
where t is the final value on the x axis
[T,X] = ode45(@funsys, [0 t], [0 0 0 0]);
plot(T, X(:,1), 'Parent', handles.axes1)
plot(T, X(:,2), 'Parent', handles.axes2)
plot(T, X(:,3), 'Parent', handles.axes3)
plot3(X(:,1),X(:,2),X(:,3), 'Parent', handles.axes4)
I am using the following function stored in a separate m file
function diff_f=funsys(t,x,A,B,C,E,F)
diff_f=zeros(4,1);
diff_f(1)=x(2);
diff_f(2)=x(3);
diff_f(3)=x(4);
diff_f(4)=(F*exp(-0.1*t)*cos(t)+B*x(4)-C*t*x(3)+E*x(2))/A;
end
Whenever I run it I receive an error message:
Not enough input arguments.
Error in funsys (line 7)
diff_f(4)=(F*exp(-0.1*t)*cos(t)+B*x(4)-C*t*x(3)+E*x(2))/A;
I tried using syms x to see if x is the problem, otherwise all other arguments are present.
Réponses (0)
Voir également
Catégories
En savoir plus sur Ordinary Differential Equations dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!