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

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 2020-05-12 0:12, Rick Newbie wrote:
> I think the blog article is more about the general mindset behind this.

The article is IMO a hysterical and prejudiced overreaction from someone 
who shows no understanding of the role of Monte Carlo simulations in 
science, nor of the programming practices of scientists ten or more 
years ago when the program was started.

Some of the comments to the article also make these points, I'm glad to see.

> Of course a C program can be correct. So can an assembler program. That 
> does not mean that it is very likely to be correct. I think we all agree 
> that language features can be a big help in writing correct programs.


Certainly. But the likelihood of a program being correct depends much 
more on the skill and care taken by the programmer, than on the 
differences between, say, C and Ada. Regarding this particular program, 
read the tweet from John Carmack which I quoted in another post.

> But even if the program was correct and produces "correct" results for 
> the data put in, that does not mean that the algorithms themselves are 
> correct and will produce results that correlate with reality.


Of course not, but that point is not addressed in the blog "review" and 
has little to do with the comment density or language used in the 
program -- it is where the epidemiological expertise comes in. I am not 
fit to judge that, nor, it seems, is the blog author.

I do agree that computer programs used to support scientific research 
and government decisions should be of high quality, documented and 
reviewable, just as, for example, any chemical analyses or manipulations 
used in the researchs should be done competently. For programs, this is 
starting to be addressed by the scientific journals, which are starting 
to require that submitted papers should include the programs and data, 
for the reviewers to inspect and possibly re-execute. Journals are also 
increasingly archiving such materials for readers to access.

    [snip]


> But what if you realize that your software isn't producing "correct" 
> results and you want to correct your code and you just don't understand 
> it anymore?


That would of course be a problem, but there is no evidence that such a 
problem affects this particular program or its author(s).

> You gotta be honest about the flaws of your system and yourself, and
> I believe that's what the author of the blog is mostly criticizing,
> that Mr.Ferguson is narcissistic and insisted on the correctness of
> his models for selfish reasons.

The blog's complaints about non-determinism and statistics are mistaken. 
The simulation is intentionally stochastic and is meant to be executed 
multiple times to give an ensemble of scenarios. Ferguson et al. are 
right to defend this.

> So there are multiple levels to this catastrophe, the language is one 
> and the personality of the author is another one.


What catastrophe? It seems some bugs were found in the program, which 
possibly had minor effects on the predictions -- probably much smaller 
effects than the inevitable errors in the input parameters and 
assumptions. The horrific predictions from the program pushed 
governments to take strong actions to stop the spread of the virus, and 
these seem to have worked in the most affected places like New York state.

Popular and professional scientific journals and magazines have been 
warning for years and decades about future flu-like pandemics which 
could markedly reduce (or "normalize") the planet's population of Homo 
Sapiens.

The present SARS-COV-2 pandemic is still from the mild end of the 
possible.  Suppose, for example, that HIV had been as infective as the 
common flu...

-- 
Niklas Holsti
niklas holsti tidorum fi
       .      @       .