![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1363958/image.png)
Problem with ordinary differential equation
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Hello, can anyone clarify me why I'm getting a line chart with the following code and how can I fix that? My initial conditions are y(C0)=t0, and y'(C0)=0. Thanks
syms y(x) x Y
N=5;
r=0.05;
m=0.01;
p=1;
s=1;
t=0.1;
a=0.25;
b=0.25;
C0=1;
C=5;
t0= (((1-a)/a)*N^(a+b))/(r-m);
Dy = diff(y);
D2y = diff(y,2);
ode = y-((((1-a)/a)*N^(a+b))-x*m*Dy+0.5*D2y*(x^2)*(s^2))/(r-m);
[VF,Subs] = odeToVectorField(ode);
odefcn = matlabFunction(VF, 'Vars',{x,Y});
tspan = [C0 80];
ic = [t0 0];
[x1,y1] = ode45(odefcn, tspan, ic);
figure
plot(x1,y1(:,1), 'DisplayName','(x_1,y_1_1)')
grid
0 commentaires
Réponse acceptée
Star Strider
le 22 Avr 2023
The initial condition of 0 for
keeps it 0 througuout the integration.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1363958/image.png)
syms y(x) x Y
N=5;
r=0.05;
m=0.01;
p=1;
s=1;
t=0.1;
a=0.25;
b=0.25;
C0=1;
C=5;
t0= (((1-a)/a)*N^(a+b))/(r-m)
Dy = diff(y);
D2y = diff(y,2);
ode = y-((((1-a)/a)*N^(a+b))-x*m*Dy+0.5*D2y*(x^2)*(s^2))/(r-m);
[VF,Subs] = odeToVectorField(ode)
odefcn = matlabFunction(VF, 'Vars',{x,Y})
tspan = [C0 80];
ic = [t0 0];
[x1,y1] = ode45(odefcn, tspan, ic);
figure
plot(x1,y1(:,1), 'DisplayName','(x_1,y_1_1)')
grid
.
Plus de 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!