Suppression des /N aux mauvais endroits

SRI_matlab/main.m

@@ -16,7 +16,7 @@ coeffs.DeathRate = 0.04;
 coeffs.NaturalDeathRate = 0.002;
 coeffs.NatalityRate = 0.003;
 
-N = 10000;
+N = 30;
 
 Slist = zeros(1, N);
 Ilist = zeros(1, N);
@@ -25,10 +25,10 @@ Rlist = zeros(1, N);
 t = 1:N;
 
 for i=t
-    input = step(input, coeffs);
     Slist(i) = input(1);
     Ilist(i) = input(2);
     Rlist(i) = input(3);
+    input = step(input, coeffs)
 end
 
 % figure
@@ -43,4 +43,4 @@ legend('Susceptible', 'Infected', 'Immunized');
 title('Evolution of virus in population');
 xlabel('Time');
 ylabel('Population');
-% axis([1, N, 0, n_pop]);
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+axis([1, N, 0, inf]);
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SRI_matlab/step.m

@@ -5,9 +5,9 @@ R = X(3);
 
 N = S + I + R;
 
-dS = -options.InfectionRate * S * I / N - options.VaccinationRate * S / N + options.ImmunisationLossRate * R + options.NatalityRate - options.NaturalDeathRate * S/N;
+dS = -options.InfectionRate * S * I/N - options.VaccinationRate * S + options.ImmunisationLossRate * R + options.NatalityRate - options.NaturalDeathRate * S;
 dI = options.InfectionRate * S * I/N - options.ImmunisationRate * I - options.DeathRate * I;
-dR = options.ImmunisationRate * I + options.VaccinationRate * S / N - options.ImmunisationLossRate * R - options.NaturalDeathRate * R/N;
+dR = options.ImmunisationRate * I + options.VaccinationRate * S - options.ImmunisationLossRate * R - options.NaturalDeathRate * R;
 
-res = [S + dS, I + dI, R + dR];
+res = [max(S + dS, 0), max(I + dI, 0), max(R + dR, 0)];
 end
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