SIR on a Network
Force-directed layout — click a node to infect it
S
I
R
Click a node to start epidemic
β (infection prob/step):
0.15
γ (recovery prob/step):
0.05
Nodes:
60
Erdos-Renyi graph
Scale-free (BA) graph
Small-world graph
Reset epidemic
Network SIR
At each step, each I node infects each S neighbor with probability β, and recovers with probability γ.
Scale-free
(Barabási-Albert) networks have hubs — super-spreaders. Epidemics spread faster.
Small-world
(Watts-Strogatz) networks combine clustering with short paths — fast global spread despite local structure.