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How to fix ode graphs?

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Fatemeh
Fatemeh am 20 Apr. 2023
Kommentiert: Star Strider am 20 Apr. 2023
Hello, I'm trying to combine these two ode plots into one chart, but it gives me two different charts. Can someone please help me with this?
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= N+r+t*p*s-m;
t1=-(N+r+t*p*s-m);
Dy = diff(y);
D2y = diff(y,2);
ode = y-(1/x)*(N+r)-((t*p*s*Dy)/y)+((Dy*((s^2)-m))/y)+((D2y*x*(s^2))/(2*y));
[VF,Subs] = odeToVectorField(ode);
odefcn = matlabFunction(VF, 'Vars',{x,Y});
tspan = [C0 80];
ic = [t0 t1];
[x,y] = ode45(odefcn, tspan, ic);
figure
plot(x, y)
grid
hold on
syms y(x) x Y
f=(x+(x^2+4*r*x*(1-a-b))^0.5)/(2*(1-a-b));
t00=N/C;
t11=-N/(C^2);
Dy = diff(y);
D2y = diff(y,2);
ode2= y-((C-x+f*((1/(r+f))^(1/(1-a-b)))+t*p*s*x*Dy+x*Dy*((s^2)-m)+Dy*(C-x)+0.5*D2y*(x^2)*(s^2)-x*(s^2)*Dy)/x*(1+t*p*s-m));
[VF1,Subs1] = odeToVectorField(ode2);
odefcn1 = matlabFunction(VF1, 'Vars',{x,Y});
tspan2 = [C 1];
ic2 = [t00 t11];
[x,y] = ode45(odefcn1, tspan2, ic2);
figure
plot(x, y)
grid
hold off

Akzeptierte Antwort

Star Strider
Star Strider am 20 Apr. 2023
You are telling it to produce two different plots because of two separate figure calls.
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= N+r+t*p*s-m;
t1=-(N+r+t*p*s-m);
Dy = diff(y);
D2y = diff(y,2);
ode = y-(1/x)*(N+r)-((t*p*s*Dy)/y)+((Dy*((s^2)-m))/y)+((D2y*x*(s^2))/(2*y));
[VF,Subs] = odeToVectorField(ode);
odefcn = matlabFunction(VF, 'Vars',{x,Y});
tspan = [C0 80];
ic = [t0 t1];
[x1,y1] = ode45(odefcn, tspan, ic);
figure
plot(x1, y1)
grid
hold on
syms y(x) x Y
f=(x+(x^2+4*r*x*(1-a-b))^0.5)/(2*(1-a-b));
t00=N/C;
t11=-N/(C^2);
Dy = diff(y);
D2y = diff(y,2);
ode2= y-((C-x+f*((1/(r+f))^(1/(1-a-b)))+t*p*s*x*Dy+x*Dy*((s^2)-m)+Dy*(C-x)+0.5*D2y*(x^2)*(s^2)-x*(s^2)*Dy)/x*(1+t*p*s-m));
[VF1,Subs1] = odeToVectorField(ode2);
odefcn1 = matlabFunction(VF1, 'Vars',{x,Y});
tspan2 = [C 1];
ic2 = [t00 t11];
[x2,y2] = ode45(odefcn1, tspan2, ic2);
figure
plot(x2, y2)
grid
hold off
figure % All Together 1!
plot(x1,y1(:,1), 'DisplayName','(x_1,y_1_1)')
hold on
plot(x1,y1(:,2), 'DisplayName','(x_1,y_1_2)')
plot(x2, y2(:,1), 'DisplayName','(x_2,y_2_1)')
plot(x2, y2(:,2), 'DisplayName','(x_2,y_2_2)')
hold off
grid
legend('Location','best')
figure % All Together 2!
yyaxis left
plot(x1,y1(:,1), 'DisplayName','(x_1,y_1_1)')
hold on
plot(x1,y1(:,2), 'DisplayName','(x_1,y_1_2)')
hold off
yyaxis right
plot(x2, y2(:,1), 'DisplayName','(x_2,y_2_1)')
hold on
plot(x2, y2(:,2), 'DisplayName','(x_2,y_2_2)')
hold off
grid
legend('Location','best')
The ‘x’ limits in the two integrations are not the same.
.
  2 Kommentare
Fatemeh
Fatemeh am 20 Apr. 2023
Thank you so much.
Star Strider
Star Strider am 20 Apr. 2023
As always, my pleasure!

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