[PULL REQUEST] VPM-B

Robert Helling helling at atdotde.de
Wed Jul 1 00:04:34 PDT 2015


Good morning Jan,

> On 01.07.2015, at 08:04, Jan Darowski <jan.darowski at gmail.com> wrote:
> 
> Dirk: fine, I agree that these commits aren't of the highest quality.
> One of the reasons is that this work is based in huge part on the
> existing implementation which I had to discover part by part and which
> has a lot of strange solutions (including units and constants scaled
> all the time). The other reason is probably my negligence. I hope to
> have all of this repaired by Friday.

No problem. This is how coding works. You try things out and something works, something else doesn’t and has to be changed later. I believe Dirk’s comments are really about how you present things to the world: You should redo the commits in a way that it looks like you got everything right in the first place. In your situation now, I would start with all your patches together and then split everything into small meaningful patches with explanatory commit messages using git add -p. This should not be too painful. Just make sure that the code builds and runs without immediate crashes after each commit so people don’t run into problems when later bisecting.

>> There is one thing that I did not expect: I printed the final allowable
>> gradients and the deeper and longer the dives get, the gradients increase. I
>> must say I expected the opposite. But maybe that is my flawed understanding
>> of the model.
> 
> Without thinking too much: it's fine for the deeper dives to have
> bigger gradients. The smaller the radius at the start of deco, the
> bigger the gradient (bigger pressure needed to make the nucleon turn
> into bubble). Gas saturation in the tissue increases slowly during the
> descent so if we descent quickly, nucleon shrinks a lot (gas pressure
> inside the bubble much bigger than saturation), so quick, deep descent
> -> big gradient.

OK, if we produce the correct plans then this is what the model is like (and my intuition was wrong).

> Longer time at the bottom should let the saturation increase, making
> the nucleon bigger and decreasing the gradient... But besides nuclear
> regeneration algorithm seems to completely ignore this part of the
> dive (the saturation increases so the first deco stop is deeper what
> increases deco time but that's not connected to the gradient). I will
> test this, maybe I'm missing something.



I think this whole bubble regeneration is totally useless as the half time is two weeks so it has no influence to any diving (at least during one day).

I will play some more with your code during the day but first some real work (paid).

Best
Robert
--
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Robert C. Helling     Elite Master Course Theoretical and Mathematical Physics
                      Scientific Coordinator
                      Ludwig Maximilians Universitaet Muenchen, Dept. Physik
                      Phone: +49 89 2180-4523  Theresienstr. 39, rm. B339
                      http://www.atdotde.de

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