ODE45 SIR model problem
조회 수: 4 (최근 30일)
이전 댓글 표시
Hi, I'm quite new to MATLAB and recently tried to plot a SIR model using its first order equations, but everytime I tried to use the ODE45 it the equation doesn't seem to change it just gives me a constant plot of the initial value. Can anyone spot a problem? Code is below:
clear all, close all, clc
A = 0.1;
B = 0.3;
tspan = [0:0.01:300];
y0 = [300 0 0];
[t,y] = ode45(@(t,y)odefcn(y,A,B),tspan,y0);
plot(t,y)
function dydt = odefcn(y,A,B)
dydt = zeros(3,1);
dydt(1) = -A*y(2)*y(1);
dydt(2) = A*y(2)*y(1)-B*y(2);
dydt(3) = B*y(2);
end
댓글 수: 0
채택된 답변
Bjorn Gustavsson
2020년 11월 19일
In your initial conditions you have everyone perfectly "healthy" - therefore no one will ever get infected. You have to set at leas some small fraction of your population to infected. That is something like this:
y0 = [299 1 0];
That should kick things off...
HTH
추가 답변 (0개)
참고 항목
제품
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!