Re: Not to incite a language war but apparently the Corona lockdown was based on 13 year old undocumented C-Code

[Optikos <ZUERCHER_Andreas@outlook.com>]

On Wednesday, May 13, 2020 at 9:05:50 AM UTC-5, Niklas Holsti wrote:
> On 2020-05-13 16:52, Optikos wrote:
> > On Wednesday, May 13, 2020 at 4:36:15 AM UTC-5, Niklas Holsti wrote:
> >> On 2020-05-13 1:39, Jeffrey R. Carter wrote:
> >>> On 5/13/20 12:20 AM, Niklas Holsti wrote:
> >>>>
> >>>> I agree that it would be troubling. If you could find that statement,
> >>>> it would interest me.
> >>>
> >>> In https://lockdownsceptics.org/code-review-of-fergusons-model/ it says,
> >>> "the code produces critically different results, even for identical
> >>> starting seeds and parameters."
> >>
> >> While the review claims that as a general flaw, it then "illustrates"
> >> the claim by discussing the two cases I detailed, in particular the
> >> unexpected influence of the option controlling how the program "stores
> >> data tables". This was eventually traced to a difference in the way the
> >> program used the RNG, depending on this option, which then led to
> >> different PRN sequences, depending on this option. An error in the
> >> program, of course, but not non-determinism.
> >>
> >> For programs that use RNGs to drive simulations, a single extra RNG
> >> call, or a single omitted RNG call, will completely change the
> >> subsequent PRN sequence. This has no effect on the statistical
> >> properties of the results from many runs, but will of course change the
> >> results of the particular run in which the change occurs.
> >>
> >>> Initially it was claimed that this was
> >>> only true for multiple cores, but later that was retracted: "But
> >>> Edinburgh came back and reported that – even in single-threaded mode –
> >>> they still see the problem."
> >>
> >> It seems that some users (Edinburgh) reported that the results varied,
> >> and reported they were using multi-core mode. The authors of the program
> >> (Imperial) replied that result variations are expected in multi-core
> >> mode; this was of course a sloppy analysis of the problem, but not an
> >> unnatural one. When the users reported that the problem occurs also in
> >> single-core mode, depending on the "data table storage" option, the
> >> authors found and fixed the error.
> > 
> > On which date did they fix the problem?  Before or after governments
> > acted on the miscalculations?
> 
> There has been no demonstration that the early predictions from this 
> program, that prodded governments into action, were "miscalculations" to 
> any significant degree, especially after the recommended practice of 
> performing several runs and considering the ensemble of results.

https://www.cato.org/blog/how-one-model-simulated-22-million-us-deaths-covid-19

https://www.spectator.co.uk/article/six-questions-that-neil-ferguson-should-be-asked/amp

2.2 million deaths in the USA and a half million deaths in the UK due to Covid-19 (reprising Neil Ferguson's prior years of off-by-orders-of-magnitude analogous sensationalism that turned out to be wholesale inaccurate in Mad Cow, H1N1, H5N1, foot & mouth disease) were not a miscalculation, but rather a perfectly accurate calculation.  Okey dokey, then.