[PATCHES] Re: Problem with VPM-B in master

[Rick Walsh]

On 23 August 2015 at 18:52, Robert C. Helling <helling at atdotde.de> wrote:

> Hi,
>
> On 23 Aug 2015, at 00:25, Rick Walsh <rickmwalsh at gmail.com> wrote:
>
> Note that to my knowledge this only occurs calculating the ceiling for
> profile.c, not when calculating the plan.  Yes, I'm repeating myself but
> that could save hours of debugging.
>
>
> here is another attempt. This at least computes the correct roots and
> avoids the division by zero thanks to some algebraic simplifications.
>

Very nice formulae there.  It's been a while since I was a student, which
was the last time I had to solve "difficult" equations.  I had a feeling
trigonometry was useful somehow in avoiding needing complex numbers, but
couldn't remember how.

I played around with this a bit, and not surprisingly, I haven't managed to
produce any errors.

Could we use this method again in calc_inner_pressure?  If I weren't about
to go to bed, I'd see if I could simplify that function similarly.

For some reason that wasn't obvious, I couldn't apply your patch directly
to the master, but the changes were trivial to make by hand.


>
>
> Patch 2 I sent remains valid.
>
> This definitely deals with the symptoms. But there might still be a
> problem with the profile ceiling calculations as when calculating the
> 60min at 100m dive there is a ceiling violation shown. This needs some
> further care. Will do this later.
>

Yes, there are very small ceiling violations in some cases I've tried.  If
you can't devise a precise method to calculate a gradient that agrees
exactly with the planned dive, we could relax the definition of a ceiling
violation to excuse small (e.g. 0.3 m) violations.

Cheers,

Rick
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.subsurface-divelog.org/pipermail/subsurface/attachments/20150823/5bd29821/attachment.html>