SIR模型是传染病模型中最经典的模型，其中S表示易感者，I表示感染者，R表示恢复者。SIR模型中，染病人群为传染的源头,他通过一定的几率把传染病传给易感人群,他自己也有一定的几率/可以被治愈并免疫,或者死亡;易感人群一旦被感染,就又成为了新的传染源。将人群划分为三类，易感染者、已感染者和已恢复者(recovered )。(The SIR model is the most classic model in the infectious disease model, where S represents a susceptible person, I represents an infected person, and R represents a recovering person. In the SIR model, the infected patient group is the source of infection. He transmits the infectious disease to the susceptible population through a certain probability. He also has a certain chance/can be cured and immunized, or died; once the susceptible population is infected, it is again Become a new source of infection. The population is divided into three categories, susceptible to infection, infected and recovered.)