SIR模型求解附件1：SIR模型程序function f=sorS(1)=14000000;I(1)=1;R(1)=0;

SIR模型求解
附件1：SIR模型程序
function f=sor
S(1)=14000000;I(1)=1;R(1)=0;na=0.126;F=19;L=19;JU=19;M(1)=1;
for i=2:74 %初期与爆发期
if i>=40&i=40
na=na-0.01/35; %爆发期 缓慢减少
end
S(i)=S(i-1)-na*S(i-1)*I(i-1)/14000000; I,R
if i>L+2
R(i)=S(i-L-2)-S(i-L-1);
else
R(i)=0;
end
if i>=51
F=F-0.5;L=fix(F);
if F==L
R(i)=S(i-L-3)-S(i-L-1);
end
end
I(i)=I(i-1)+na*S(i-1)*I(i-1)/14000000-R(i);
t=log(abs(14000001-S(i)))/log(10);
o(i)=abs(14000001-S(i));p=log(o(i)-o(i-1))/log(10);
plot(i+JU-19,t,'sr'),hold on,plot(i+JU-19,t,'sr'),
if p>0.1
plot(i+JU-19,p,'or'),plot(i+JU-19,p,'or')
end
end
h=na;g(1)=17;n=1;
for i=75:139 %高峰期与衰减期
n=n+1;
if i