I am trying to plot differential equations using ode45 and not getting a graph

2021 12 19
1 个回答
回答已采纳
更新时间：2021 12 19
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IC = [93000;1000;1000;50;50;0;500];
tspan = [0 70];
[t,Y] = ode45(@odefun, tspan, IC);
for i = 1:size(Y, 2)
plot(t, Y(:, 1))
hold on
plot(t, Y(:, 2))
plot(t, Y(:, 3))
plot(t, Y(:, 4))
plot(t, Y(:, 5))
plot(t, Y(:, 6))
plot(t, Y(:, 7))
hold off
end
function DYdt = odefun(t,Y)
S = Y(1);
EA = Y(2);
EB = Y(3);
IA = Y(4);
IS = Y(5);
R = Y(6);
P = Y(7);
b=0.00018;
mu=0.0004563;
muP=0.1724;
alpha1=0.10;
alpha2=0.10;
beta1=0.00414;
beta2=0.0115;
delta=0.7;
O=0.7;
psi2=0.0051;
psi1=0.002;
omega1=0.22;
omega2=0.09;
sigma=0.0018;
gammaS=0.05;
gammaA=0.0714;
etaS=0.1;
etaA=0.05;
dSdt = b-((2*beta1*S*P)/(1+alpha1*P))-(2*beta2*S*(IA+IS)/1+alpha2*(IA+IS))+(psi1*EA)+(psi2*EB)-(mu*S);
dEAdt = ((beta1*S*P)/(1+alpha1*P))+(beta2*S*(IA+IS)/1+alpha2*(IA+IS))-(psi1*EA)-(mu*EA)-(omega1*EA);
dEBdt = ((beta1*S*P)/(1+alpha1*P))+(beta2*S*(IA+IS)/1+alpha2*(IA+IS))-(psi2*EB)-(mu*EB)-(omega2*EB);
dIAdt = ((1-delta)*omega1*EA)-((1-O)*omega2*EB)-(mu+sigma)*IA-(gammaS*IA);
dISdt = (delta*omega1*EA)-(O*omega2*EB)-(mu+sigma)*IS-(gammaS*IS);
dRdt = (gammaS*IS)+(gammaA*IA)-(mu*R);
dPdt = (etaA*IA)+(etaS*IS)-(muP*P);
DYdt = [dSdt; dEAdt;dEBdt;dIAdt; dISdt; dRdt; dPdt];
end

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 采纳的回答

Torsten
Torsten 2021-12-19
编辑：Torsten 2021-12-19

0 个投票

function main
IC = [93000;1000;1000;50;50;0;500];
tspan = [0 25];
[t,Y] = ode45(@odefun, tspan, IC);
plot(t, Y)
end
function DYdt = odefun(t,Y)
S = Y(1);
EA = Y(2);
EB = Y(3);
IA = Y(4);
IS = Y(5);
R = Y(6);
P = Y(7);
b=0.00018;
mu=0.0004563;
muP=0.1724;
alpha1=0.10;
alpha2=0.10;
beta1=0.00414;
beta2=0.0115;
delta=0.7;
O=0.7;
psi2=0.0051;
psi1=0.002;
omega1=0.22;
omega2=0.09;
sigma=0.0018;
gammaS=0.05;
gammaA=0.0714;
etaS=0.1;
etaA=0.05;
dSdt = b-((2*beta1*S*P)/(1+alpha1*P))-(2*beta2*S*(IA+IS)/1+alpha2*(IA+IS))+(psi1*EA)+(psi2*EB)-(mu*S);
dEAdt = ((beta1*S*P)/(1+alpha1*P))+(beta2*S*(IA+IS)/1+alpha2*(IA+IS))-(psi1*EA)-(mu*EA)-(omega1*EA);
dEBdt = ((beta1*S*P)/(1+alpha1*P))+(beta2*S*(IA+IS)/1+alpha2*(IA+IS))-(psi2*EB)-(mu*EB)-(omega2*EB);
dIAdt = ((1-delta)*omega1*EA)-((1-O)*omega2*EB)-(mu+sigma)*IA-(gammaS*IA);
dISdt = (delta*omega1*EA)-(O*omega2*EB)-(mu+sigma)*IS-(gammaS*IS);
dRdt = (gammaS*IS)+(gammaA*IA)-(mu*R);
dPdt = (etaA*IA)+(etaS*IS)-(muP*P);
DYdt = [dSdt; dEAdt;dEBdt;dIAdt; dISdt; dRdt; dPdt];
end

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