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November 1, 2022

Categories and Epidemiology

Posted by John Baez

I gave a talk about my work using category theory to help design software for epidemic modeling:

• Category theory and epidemiology, African Mathematics Seminar, Wednesday November 2, 2022, 3 pm Nairobi time or noon UTC. Organized by Layla Sorkatti and Jared Ongaro.

This talk is a lot less technical than previous ones I’ve given on this subject, which were aimed mainly at category theorists. You can watch it on YouTube.

Here’s the abstract:

Category theory provides a general framework for building models of dynamical systems. We explain this framework and illustrate it with the example of “stock and flow diagrams”. These diagrams are widely used for simulations in epidemiology. Although tools already exist for drawing these diagrams and solving the systems of differential equations they describe, we have created a new software package called StockFlow which uses ideas from category theory to overcome some limitations of existing software. We illustrate this with code in StockFlow that implements a simplified version of a COVID-19 model used in Canada. This is joint work with Xiaoyan Li, Sophie Libkind, Nathaniel Osgood and Evan Patterson.

Check out these papers for more:

For some more mathematical talks on the same subject, go here.

Posted at November 1, 2022 11:05 PM UTC

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Re: Categories and Epidemiology

Great to have you speak in the African Mathematics Seminar John! And thanks to Layla Sorkatti for hosting, and as always, to Jared Ongaro for organizing.

Posted by: Bruce Bartlett on November 3, 2022 4:17 PM | Permalink | Reply to this

Re: Categories and Epidemiology

It was great speaking there, and the music before and after was a great touch. It’s amazing how much a bit of music changes my mood, especially in an unexpected context like a math talk!

Posted by: John Baez on November 4, 2022 12:03 PM | Permalink | Reply to this

Re: Categories and Epidemiology

Can you make your slides available, if you had some?

Posted by: David Roberts on November 4, 2022 10:21 AM | Permalink | Reply to this

Re: Categories and Epidemiology

Yes, you can now watch my talk on YouTube and get the slides here.

The slide with nothing but a four-part picture has an interesting tale to go with it, which explains why diagrammatic methods are so useful for getting lots of people in a community involved in modeling. I tell this tale in the YouTube video. This tale goes back to Peter Hovmand, and it may be told in this paper:

  • Peter Hovmand, Group model building and community-based system dynamics process, in Community Based System Dynamics, Springer, Berlin, pp. 17–30.
Posted by: John Baez on November 4, 2022 11:38 AM | Permalink | Reply to this

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