Modeling SIR in matlab and simulink help needed

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Hello, I am trying to model a SIR epidemic model in matlab and simulink. I think I've already done it in matlab but for some reason my simulink model won't work. It just shows straight lines in a scope. This is my function to calculate differential equations.
function dx = sir(t, x)
dx = [0; 0; 0];
beta = .5;
delta = .3;
dx(1) = -beta * x(1) * x(2);
dx(2) = beta * x(1) * x(2) - delta * x(2);
dx(3) = delta * x(2);
end
This is my workspace code to show plot
and this is mu simulink with yields this strange plot and this is after autoscaling with initial conditions set to S = 7900000 and R = 0 and I = 10
%
  2 Comments
Alaa Mohamed
Alaa Mohamed on 5 May 2020
I am working on the same model rightnow, but for some reason the plot code is not running, could you help me?
MICHAEL Veneziano
MICHAEL Veneziano on 13 Feb 2021
could it be that with an S many times greater than I, I seems 0? try running it for a longer time or witha greater I or beta

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Answers (1)

CIRO ANTONIO MAMI
CIRO ANTONIO MAMI on 10 Jul 2022
Same problem here, did you find any solutions?

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