GSoC Status - Week 7 (VPM-B)

[Rick Walsh]

Hi Jan,

On 14 Jul 2015 6:53 am, "Jan Darowski" <jan.darowski at gmail.com> wrote:
>
> Hi!
> This week I wrote a Boyles law compensation and checked all the
> calculations to find the root of the differences of results against
> the original implementation.
>
> I found that there is a difference between the code and papers in one
> of the CVA formulas. I need to add one more calculation, which will
> estimate the time at the surface required for the diver to fully
> regenerate.
>
> Another important thing, is that the Boyles law compensation seems to
> be just stupid. It scales the allowable gradients based on the
> nucleons radius at the first deco stop. The problem is, even very
> small difference in the tissue saturation or different way of ascent
> simulation can cause the diver to have the first stop sooner or later.
> Then, gradients are scaled against different radius, which has a huge
> influence on the total deco time.
>
> I will confirm it but for now, on one of the tests I had a minute of
> difference without Boyles compensation and 235 vs 289min with it on.
> That's way too much.

Are you using the same base critical radii? For consistency with other
implementations we should use critical radii of 0.55 and 0.45 for the
Boyles law correction, cf 0.8 and 0.7 without Boyles law correction.
See:
http://www.hhssoftware.com/images/critrad.gif

>
> --
> Jan Darowski
> _______________________________________________
> subsurface mailing list
> subsurface at subsurface-divelog.org
> http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.subsurface-divelog.org/pipermail/subsurface/attachments/20150714/760da70e/attachment-0001.html>