% SEIR Model uses seirf.m for the ODE system
% y(1) = S,y(2) = E, y(3) = I, y(4) = R
% Time is measured in days

clear
global beta sigma gamma f N
beta=0.27;
sigma=1/5.3;
gamma=1/5.61;
f = 0.74;

t0=0;
tf=250;
N=10^6;
NI=50;
NE=0*N;

[t,y]=ode45('seirf',[t0,tf],[N-NI-NE,NE,NI,0]);
plot(t,y(:,2),t,y(:,3),t,y(:,4))
xlabel('Time')
ylabel('Populations')
legend('Exposed','Infectious','Removed')