# SIRE with vaccine model

12 views (last 30 days)
Campbell Gorrie on 24 Oct 2021
Answered: Alan Stevens on 24 Oct 2021
%Hey im just trying to graph S,I, R, E at the bottom but anytime i click run it comes up blank
function SEIR
N = 5185002;
v = 46.25;
b = v*2.2;
m=0.7
k= 30
a = 62.93;
function dF = rigid(t, x);
dF = zeros(8,1);
dF(1) = - b*(x(5)+x(6))*x(1)/N+k*x(7);
dF(2) =- b*m*(x(5)+x(6))*x(2)/N ;
dF(3) =b*(x(5)+x(6))*x(1)/N - (a)*x(3);
dF(4) =b*m*(x(5)+x(6))*x(2)/N - m*(a)*x(4);
dF(5) =(a)*x(3)-v*x(5);
dF(6) =m*((a)*x(4)-v*x(6));
dF(7) =v*x(5)-k*x(7);
dF(8)=v*m*x(6);
end
options = odeset('Refine', 10, 'RelTol', 1e-4);
[t,y] = ode45(@rigid, [0 1.5], [(5185000*0.3) (5185000*0.7) 1 1 0 0 0 0], options); .
S= y(1)+y(2);
E= y(3)+y(4);
I= y(5) +y(6);
R= y(7)+y(8)
plot(t,(y(1)+y(2)),t,(y(3)+y(4)),t,(y(4)+y(5)),t,(y(6)+y(7)))
title('SEIR model')
legend('S','E','I', 'R')
end

Alan Stevens on 24 Oct 2021
Like this
tspan = [0 1.5];
options = odeset('Refine', 10, 'RelTol', 1e-4);
y0 = [5185000*0.3 5185000*0.7 1 1 0 0 0 0];
[t,y] = ode45(@rigid, tspan, y0, options);
S= y(:,1)+y(:,2);
E= y(:,3)+y(:,4);
I= y(:,5) +y(:,6);
R= y(:,7)+y(:,8);
plot(t,S,t,E,t,I,t,R)
title('SEIR model')
legend('S','E','I', 'R')
function dF = rigid(~, x)
N = 5185002;
v = 46.25;
b = v*2.2;
m=0.7;
k= 30;
a = 62.93;
dF = zeros(8,1);
dF(1) = - b*(x(5)+x(6))*x(1)/N+k*x(7);
dF(2) =- b*m*(x(5)+x(6))*x(2)/N ;
dF(3) =b*(x(5)+x(6))*x(1)/N - (a)*x(3);
dF(4) =b*m*(x(5)+x(6))*x(2)/N - m*(a)*x(4);
dF(5) =(a)*x(3)-v*x(5);
dF(6) =m*((a)*x(4)-v*x(6));
dF(7) =v*x(5)-k*x(7);
dF(8)=v*m*x(6);
end