[PULL REQUEST] VPM-B Attempt 2.

[Jan Darowski]

Thanks for checking it.

> But then I checked the configuration parameters adopted, and there are
> differences.  I altered vpmb_config to match what was used in the Fortran
> code.
> critical radius of N2 was 0.6, changed to 0.8 microns
> critical radius of He was 0.5, changed to 0.7 microns
> critical volume of lambda was 250, changed to 231.021 bar (=7500 fsw-min)

eh... from deepocean.net: "7500 fsw min = 250 bar min"
It's not the first mistake I found there. And it seems that the author
of existing
c code based his implementation on this site also.

> Using these configuration parameters, we get total dive times of 101 and 125
> minutes, respectively.  I.e.within 1 minute (which is nothing) of the
> example dives.  It would be a huge coincidence if the calculations weren't
> being performed correctly.

That's nice to hear.

> I can't claim these configuration parameters are 'better', but with them, we
> can match the benchmark.  A patch is attached.  You may or may not want to
> take it: when the Boyles Law adjustment is made, I think the critical radii
> should be reduced back to how they were, but the lambda parameter should
> also be reduced to ~200 bar.
>
> I also attached a patch to include the units in the config structure, to
> make it marginally easier to understand what the parameters represent.

Thanks for the patch, units can be in fact pretty useful.

I guess I need to implement Boyle's law as soon as possible and only
test against
the original fortran code...

-- 
Jan Darowski