Abstract
Infectious diseases have been posing a major threat and hazard on the biologic circle. Therefore, it is of great significance to reveal the mechanism of the spread of infectious diseases by the means of forecast and control. One of the important methods is to use graphics software MATLAB to conduct numerical simulation through the establishment of mathematical models. This paper intends to make a study on the SI model of one type become adult a kind a cluster to have disease but childhood kind cluster not to have disease. The major steps are to use the MATLAB mathematical software to simulate the figures, to investigate the overall of the SI epidemic model. So the data processing advantage of numerical simulation contributes to more intuitive results. Through the constant equation of the internal value of all the different assignment get different results, comparative analysis of the results of the meaning of that SI model is stable, thus proving that the findings of the original theory is correct.
Key words: local stability; delay; global attractively; SI epidemic model
