SimEpidemic1: An Individual-based Epidemic Simulator

Developed by Tatsuo Unemi, Soka University
unemi at soka dot ac dot jp
June 1st, 2020, updated on June 7, 2022.

This is a simulator for epidemic using a model of probabilistic state transition of individuals on infection, disease, quarantine, recovery, and death. It starts with a randomly placed thousands of individuals including one or more infected persons, then progresses assuming some simulation steps corresponds to one day.

You can change the parameters on infection probability, distribution of incubation periods, distribution of symptom progress, distribution of turning period toward recovery, and distribution of effective immunity duration, together with the population size, the area size, and the number of steps per day.

It is also allowed to set up the rate and delay of quarantine for the infected individuals of each of asymptomatic and symptomatic, strength of social distancing and the rate of obedience, and the frequency and distance of individual mobility.

The simplified p5.js version is easy to try on your web browser, not only on a personal computer but also on a smart phone. However, it runs smoothly for three or four thousands of individuals, but it gets slower when you try larger population. On the other hand, in the version of macOS application, it is possible to handle more than ten thousands individuals by utilizing the thread parallelism. In addition to the advantage in speed, it has a useful functionality to save and open the parameter settings, and even you can design a scenario in which the parameters change at the intermediate moments when the specified conditions are satisfied on some statistic indexes, such as the percentage of individuals in quarantine. From the version 1.5, the system simulates Tests and Contact Tracing.

Sorry, but the documentation for the technical detail is still under preparation. Here are documents in Japanese language that might be helpful for you.

This is a type of so called Toy Model, but a bit sofisticated than ussual. The author is hoping this could contribute any portion to cope with the current and future's difficult situation in the world due to SARS-CoV-2 and COVID-19.

You can use the code of p5.js version in any manner you want, but in case you plan to open the web site including some parts of the code in public, please inform me of the URL. Any comments are welcome.


Created in June 1, 2020, updated on June 7, 2022.