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Cuchulainn
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Re: Models for Covid-19

September 24th, 2020, 12:09 pm

One can look at it in different ways from the perspective of mathematics, but I think the answer for you is that in a classic diffusion model you can go in either direction with an equal probability. In a percolation model you can access some sites with a certain probability. Vide anomalous diffusion.

@"I feel the above is a case of argumentum ad verecundiam."

It probably means that you need to educate yourself a bit on the subject(s) if you want to discuss them ;-
What's it got to do with SIR and predicting a 2nd wave? Is it a solution looking for a problem.
Waiting for your next jibe ..
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

September 25th, 2020, 1:41 pm

Many epidemiologists use network models of contagion / directed percolations. The critical behaviour is at the threshold between the active and the absorbing regime (cf R0).

Just another model?

You mean, discrete percolation which is a specialisation of continuous percolation?
What' your rationale for wanting to model discrete individuals. I find flow in porous media more intuitive.
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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katastrofa
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Re: Models for Covid-19

September 27th, 2020, 1:51 am

I'd say it's better/more intuitive for simulating interventions, such as the 6 person rule or optimising the track and trace system. It doesn't assume the homogeneous mixing of the population like the classic SIR.
Still, any realistic model of an epidemic needs its backbone made of an agent-based model (to describe agents and their interactions) and a network model (to describe the structure of those interactions). When you calibrate such a model to statistical data and information, we're talking - that's what I call microsimulation. Two models, but it's one model:
Image

For the record, no authority on epidemiology speaking here. Just a bored mathematical modeller spitting out her brain.
 
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Cuchulainn
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Re: Models for Covid-19

September 27th, 2020, 2:10 pm

"Black and Tan"  cat ..
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

October 6th, 2020, 6:15 pm

How Trump b****xed Science — and why it could take decades to recover

https://www.nature.com/articles/d41586-020-02800-9

On thing is sure: you can forget those piddly SIR models.
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

October 10th, 2020, 7:43 pm

Image
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Paul
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Re: Models for Covid-19

October 21st, 2020, 7:18 pm

Zulu
 
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Cuchulainn
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Re: Models for Covid-19

October 22nd, 2020, 10:43 am

Great Barrington Declaration

https://en.wikipedia.org/wiki/Great_Bar ... eclaration

Libertarians seem to love herd immunity. Boris Johnson was in favour until Neil Ferguson dropped the bombshell on  March 16.


The Great Barrington Declaration was authored by Sunetra Gupta of the University of OxfordJay Bhattacharya of Stanford University, and Martin Kulldorff of Harvard University.[1] The costs were paid for by the American Institute for Economic Research, a libertarian think tank that is part of a Koch-funded network of organizations associated with climate change denial.[14][15]
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

October 23rd, 2020, 2:58 pm

At last night's (October 22) presidential debate Donald Trump brushed off the criticism that 250,000 died with the retort that it could have been 2.2 million based on Neil Ferguson' discredited model and software as written in my report above.

At the time Nature had said

https://www.nature.com/articles/d41586-020-01003-6

The same model suggested that, with no action, the United States might face 2.2 million deaths; it was shared with the White House and new guidance on social distancing quickly followed (see ‘Simulation shock’).
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

October 23rd, 2020, 2:59 pm

Image
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

October 28th, 2020, 7:42 pm

Covid-19 herd immunity theory dealt blow by UK research

https://www.ft.com/content/f75418a9-9ef ... 8635e906b1
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

October 31st, 2020, 6:19 pm

I wonder what (competing?) models they are using.

Image
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Joined: July 16th, 2004, 7:38 am
Location: Amsterdam
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Re: Models for Covid-19

October 31st, 2020, 6:21 pm

Sanity clause: all models have uncertainty/margin of error.
Very good.
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
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Cuchulainn
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Re: Models for Covid-19

November 3rd, 2020, 2:59 pm

Sweden, revisited

www.rte.ie/news/coronavirus/2020/1103/1 ... us-global/


"More and more intensive care beds are now being used to treat Covid patients. The respite we got this summer is over."
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
 
User avatar
Cuchulainn
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Posts: 63413
Joined: July 16th, 2004, 7:38 am
Location: Amsterdam
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Re: Models for Covid-19

November 25th, 2020, 8:41 pm

Covid models revisited, BBC2 "Lockdown 1.0 - Follow the Science"

Apart from hubris and lies from the politicians, the penitent scientists(*) don't come out unscathed. I listened twice to get all the nuances. Some of the original doubts and questions in this thread have been answered.

https://www.youtube.com/embed/035KvnhQV1U

Highly educational. The maestro was out of synch with the orchestra. And the string section were playing a different tune altogether. 

(*) no mention whether "next time better".
My C++ Boost code gives
262537412640768743.999999999999250072597198185688879353856337336990862707537410378210647910118607313

http://www.datasimfinancial.com
http://www.datasim.nl
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