MATLAB: How to change the axis of the plot of the SIR model

functiongraphMATLABmodelode45

Hello, I'm currently working on an SIR model and plotting them. However, my y-axis shows up as a range from 0 to 1, instead of 0 to the population I am using. I've tried to play around with the y-axis, but it drastically changes my plots. How do I render the y-axis from 0 to the population I am testing without effecting how it is plotted?
My code is shown below:
N = 59170000; 
I = 67466; 
R = 40592; 
S = N - I - R;  
s = S/N; 
i = I/N; 
r = R/N;
props = [s i r];
[t,x] = ode45('sir', [0 365], props);
plot(t,x,'LineWidth',2);
xlim([0 365]);
xticks(0:20:365);
legend('S','I','R','Location','best');
This is my SIR function:
function dx = sir(t, x)
    dx = [0; 0; 0];
    r0 = 2.28;
    gamma = 1/18;
    beta = r0*gamma; 
    dx(1) = -beta * x(1) * x(2);
    dx(2) = beta * x(1) * x(2) - gamma * x(2);
    dx(3) = gamma * x(2);
end

Best Answer

I get the following plot when I run your code.
The x-axis is from 0 to 360, as expected from xlim([0 365]). What do you expect different.
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