from soil.agents import FSM, NetworkAgent, state, default_state, prob import logging class DumbViewer(FSM, NetworkAgent): """ A viewer that gets infected via TV (if it has one) and tries to infect its neighbors once it's infected. """ prob_neighbor_spread = 0.5 prob_tv_spread = 0.1 has_been_infected = False @default_state @state def neutral(self): if self["has_tv"]: if self.prob(self.model["prob_tv_spread"]): return self.infected if self.has_been_infected: return self.infected @state def infected(self): for neighbor in self.get_neighbors(state_id=self.neutral.id): if self.prob(self.model["prob_neighbor_spread"]): neighbor.infect() def infect(self): """ This is not a state. It is a function that other agents can use to try to infect this agent. DumbViewer always gets infected, but other agents like HerdViewer might not become infected right away """ self.has_been_infected = True class HerdViewer(DumbViewer): """ A viewer whose probability of infection depends on the state of its neighbors. """ def infect(self): """Notice again that this is NOT a state. See DumbViewer.infect for reference""" infected = self.count_neighbors(state_id=self.infected.id) total = self.count_neighbors() prob_infect = self.model["prob_neighbor_spread"] * infected / total self.debug("prob_infect", prob_infect) if self.prob(prob_infect): self.has_been_infected = True class WiseViewer(HerdViewer): """ A viewer that can change its mind. """ defaults = { "prob_neighbor_spread": 0.5, "prob_neighbor_cure": 0.25, "prob_tv_spread": 0.1, } @state def cured(self): prob_cure = self.model["prob_neighbor_cure"] for neighbor in self.get_neighbors(state_id=self.infected.id): if self.prob(prob_cure): try: neighbor.cure() except AttributeError: self.debug("Viewer {} cannot be cured".format(neighbor.id)) def cure(self): self.has_been_cured = True @state def infected(self): if self.has_been_cured: return self.cured cured = max(self.count_neighbors(self.cured.id), 1.0) infected = max(self.count_neighbors(self.infected.id), 1.0) prob_cure = self.model["prob_neighbor_cure"] * (cured / infected) if self.prob(prob_cure): return self.cured