Programming Procedure in Excel for Calculating Model Variables in a New SEIR Epidemic Model Based on the latent-infectious period chronological order

Our new SEIR epidemic model built from the l-i AIR model [1] has similar terms to the conventional SEIR epidemic model [2]. We have uploaded an instruction file for describing how to write a calculation program in Excel for calculating the model variables S, E, I, R and y.
Calculation equations and results in example 1 and example 2 are the same. The difference is that we used absolute cell reference for parameters l and c in example 2. Thus, if parameters l and c are changed, we can just change the value of l in cell D2 and the value of c in cell E2 in example 2. However, in example 1, we have to change codes related to parameters l and c in all cells from B29-Bn, C29-Cn, D29-Dn and E29-En.

REFERENCES
[1] Liu, X. A simple, SIR-like but individual-based epidemic model: Application in comparison of COVID-19 in New York City and Wuhan. Results Phys 20, 103712 (2021).
[2] Liu, X. Analytical Solution of a New SEIR Model Based on Latent Period-Infectious Period Chronological Order. medRxiv, https://doi.org/10.1101/2021.12.14.21267812, 2021.2012.2014.21267812 (2021).

本研究所构建的新型SEIR传染病模型，源自l-i AIR模型[1]，其术语与传统的SEIR传染病模型[2]具有相似性。为描述如何使用Excel编写计算程序以计算模型变量S、E、I、R及y，我们已上传相应的指令文件。在示例1和示例2中，计算方程和结果均相同。区别在于，示例2中我们采用了绝对单元格引用参数l和c。因此，若需更改参数l和c，仅需在示例2中更改D2单元格中的l值和E2单元格中的c值。然而，在示例1中，必须更改与参数l和c相关的所有单元格（B29-Bn、C29-Cn、D29-Dn和E29-En）中的代码。