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Coronavirus modelling – GLEAMviz15

Here’s the kind of stuff that the Covid-19 modellers will be doing. https://www.nature.com/articles/srep46076.pdf I have downloaded GleamViz, http://www.gleamviz.org/simulator/client/, and it is quite complicated to set up (I used to have a little Windows app called Wildfire that just needed a few numbers to get a pictorial progression of life/recovery/death from the disease, depending on infectivity, time taken to kill, etc). GLEAMviz15 is a proper tool* that needs a lot of base data to be defined. I’m thinking about it! PS – Some of the GleamViz team seem to be based in Turin.
*see my comment to this post.


Such modelling reminds me of event-based simulation models I used to develop for the MoD back in the 70s, using purpose-designed programming languages such as Simscript (Fortran-like) and Simula (Algol-like), all based around what today might be called object oriented programs (OOP), where small modules of code represent micro-events that occur, having inputs that trigger them from previous (or influencing) events, and outputs that trigger subsequent (or influenced) events, all inputs and outputs coded with a probability distribution of occurrence. In the MoD case this was about – erm, what am I allowed to say! – reliability and failure rates in aircraft, refuelling tankers and cruise missiles (even then). I recall that in my opening program statement, I named it “PlayGod”. I did ask for a copy of it years later (it’s all in very large dusty decks of Hollerith cards somewhere (I did overlap with paper tape, but I was a forward looking person!)) but they refused. Obviously far too valuable to the nation (even if I wasn’t, judging by my salary).


With regard to the publication of the modelling tools, I’ll leave aside the data part of it…there is a lot, and much of it will be fuzzy, and I’m sure is very different for every country’s population, depending where they are with the disease, and what measures they have taken over a period and whether, for example, they had “super-spreaders” early on, as some countries did.


Back in the early seventies, a European macro-economic project led to the publication of a book, The Limits to Growth. The context is described in https://en.m.wikipedia.org/wiki/The_Limits_to_Growth
Not long after, our Government released the macro-economic model software they were using to explore these aspects of the performance and the future of our economy in a worldwide scenario.
I worked at London University’s commercial unit for a while, and we mounted this freely available Government model, and offered it to all-comers.


The Economist publication was one of our clients for this, and their chief economics journalist, Peter Riddell, was someone we met several times in connection with it. He was very interested in modelling different approaches (to matters such as exchange rates, money availability (monetary and fiscal policy) and their impact on economic development in a constrained environment) and report on them, as a comparison with the Government’s own modelling, policies and strategies.


This was all at a time when the Economy was perceived to be at risk (as it is now from this pandemic), and inflation and exchange rates, monetary and fiscal policy (for example) were very much seen as determinants of our welfare as a nation, and for all other nations, including the emerging European Community, who originally sponsored this work.


We seem to be in a very similar situation with regard to the modelling of this Covid-19 pandemic, and I don’t see why the software being used (at least by the UK Government’s analysts (probably academics, I think Sir Patrick Vallance said in his answers to the Select Committee this morning)) could not be released so that we might get a better understanding of the links assumed between actions and outcomes, impact of assumptions made, and the impact of actual and potential measures (and their feedback loops, positive or negative) taken in response to the outbreak.
Apparently the Government IS going to release its modelling, and I would certainly be interested to see it – its parameters, assumptions, its logic and its variety of outcomes and dependencies on assumptions. The possible outcomes are probably EXACTLY why the Government hasn’t released it yet.

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