The Fitting Research of Differential Equation by Igor Pro

Fitting data to a differential equation is different from ordinary data fitting cases. There is no explicit analytical expression to use in fitting. The fitting results are easy to diverge and the fitting program design is more difficult. Taking COVID-19 epidemic data as an example, this paper introduces the use of Igor Pro in detail by using the SEIR model of virus transmission. The basic principle of fitting data to differential equation by Igor Pro, the design of software panel, the coding of fitting function and the setting of initial parameters are analyzed. The physical meaning of fitting results and the possible limitations are analyzed. The problems needing attention when using differential equation to fit data are discussed.