1 #+date: <2023-10-29 07:15:34+0000>
2 #+filetags: :mathematics:modeling:
3 #+title: Agent-based models and digital twins.
5 A new approach to modeling using categories and software, facilitating
6 the build of advanced models like digital twins, is being developed at
9 During the 2023 SIAM Conference on Computational Science and
10 Engineering, a group of researchers
11 [[https://meetings.siam.org/sess/dsp_talk.cfm?p=124342][presented]]
15 diagrammatic representations that provide an intuitive interface for
16 specifying the relationships between variables in a system of equations,
17 a method for composing systems equations into a multiphysics model using
18 an operad of wiring diagrams, and an algorithm for deriving solvers
19 using directed hypergraphs, yielding a method of generating executable
20 systems from these diagrams using the operators of discrete exterior
21 calculus on a simplicial set. The generated solvers produce numerical
22 solutions consistent with state of the art open source tools.
25 As pointed out, mathematics can rarely be isomorphic to its software
26 implementation, yet here the researchers go a long way in enabling that.
28 Using Julia language, the applied category theorists working on this
29 concept wrote a software (StockFlow) which allows users to build
30 stock-flow diagrams and do all sorts of things with them - from drawing
31 them over to transforming them into other forms like dynamical systems
32 and system structure diagrams, or to solving the underlying differential
35 The team have also built software (ModelCollab) that hides all the Julia
36 code again, enabling people that aren't educated mathematicians or
37 computer scientists to apply this way of modeling in their work.
39 This fascinates me, as having a way to write and audit complex systems
40 like digital twins using free and open-source approaches can be
41 transformative in making them accessible for smaller organisations or
42 developed for non-core departments in bigger organisations that up to
43 now are the only ones with enough money or people to develop them for
47 [[https://johncarlosbaez.wordpress.com/2023/10/25/software-for-compositional-modeling-in-epidemiology/][John