For the COVID dimwits on this forum - I'm sure you know who you are

[minestrone]

Cease your unintelligent brain farting and read this paper. Even though it's not peer reviewed, rightly or wrongly, it's the paper that most govt. policy is now based on.
The govt having backtracked on its "herd immunity" theory a week or so ago.

https://www.imperial.ac.uk/media/imp...16-03-2020.pdf

GitHub - mrc-ide/covid-sim

CovidSim.cpp

[OwlHoot]

GitHub - mrc-ide/covid-sim

CovidSim.cpp

Apparently the code is (or was, before Microsoft and John Carmack recently worked on it) a 15000 line unfathomable, uncommented mess, from which the model is next to impossible to discern, and which produces wildly different results even when fed the same random number seed.

We, the undersigned software engineers, call for any papers based on this codebase to be immediately retracted

The authors, including the prof, maintain that the code is intended to be stochastic in that only the results of many runs using different seeds should be used. But if an individual run with the same seed cannot be replicated (due to internal randomness, presumably using other randomisation techniques such as sampling the microsecond system clock) then how can they distinguish model randomness from random code artifacts or outright bugs? Seems a simple but crucial distinction.

[jamesbrown]

and which produces wildly different results even when fed the same random number seed

[jamesbrown]

I’d like to see the unit/integration tests of that. I’m guessing there are none.

[DoctorStrangelove]

Comments are for wimps.

[OwlHoot]

I’d like to see the unit/integration tests of that. I’m guessing there are none.

I very much doubt it. But perhaps there are quantum eigentests, whose results are a superposition of all possible test results.

[minestrone]

For loop at line 61...

covid-sim/Bitmap.cpp at master . mrc-ide/covid-sim . GitHub

I'm kind of in the "coding standards don't improve code" camp. You can get a bad programmer to follow all the received wisdom on brackets, loop depth, testability but it wont make better code than a good programmer not following them.

But this code is truly fooking terrible. I mean horrific. Storing population data in a bitmap with colour for state...

/* red for infected */
/* blue for treated */
/* green for recovered */
/* grey for just people */

What is the colour for infected and untreated?

There needs to be a push to discredit this crap.

[Whorty]

For loop at line 61...

covid-sim/Bitmap.cpp at master . mrc-ide/covid-sim . GitHub

I'm kind of in the "coding standards don't improve code" camp. You can get a bad programmer to follow all the received wisdom on brackets, loop depth, testability but it wont make better code than a good programmer not following them.

But this code is truly fooking terrible. I mean horrific. Storing population data in a bitmap with colour for state...

/* red for infected */
/* blue for treated */
/* green for recovered */
/* grey for just people */

What is the colour for infected and untreated?

There needs to be a push to discredit this crap.

Red

HTH