Planner questions

[Robert C. Helling]

Willem,

let me reply to the list since there might be other who might be able to say more about the points you address.

> On 25 Oct 2015, at 11:06, Willem Ferguson <willemferguson at zoology.up.ac.za> wrote:
> 
> Hallo Robert,
> 
> Look at the attached dive log, comprising two plans that have been saved. A few questions about Subsurface 4.5.0 implementation.
> 
> 1) Look at the 60m dive. At the end of the bottom section, TTS is given as 85 minutes. Probably not correct, is it?

I guess it is correct since the TTS calculation does not do gas changes. There was a discussion about this about a few weeks ago. Maybe for 4.6 we could refactor the planner such that it can be used for the TTS calculation as well (currently, TTS is calculated by a separate mini-planner).

> 
> 2) The 60m dive has a duration of 54 minutes. The same dive on V-Planner has duration of 64 minutes. Now, I understand it is difficult to do direct comparisons, but this is quite a large difference. The conservatism on V-Planner was 3 (out of max of 5) and with Subsurface it was also 3 (out of max of 4). For all the other dive plans I tried, the agreement between Subsurface and V-Planner was quite good  for instance for the 50m dive included in this log.

Over the summer (northern hemisphere), we did an extensive comparison of Subsurface VPM-B profiles to those of other programs including the original fortran code. In the end, our times were well in the variance of the others. We did, however, only test at zero conservatism (this is what the fortran code does exclusively). I don’t have a license for v-planner (or multi-deco, its successor). Maybe somebody else can look into this more systematically?
> 
> 3) The planner gives a spinbox titled "Salinity". Now 1.03 kg of salt/liter of water gives a pretty high salinity! Took Ferguson some time to work this out!! Would it not be more useful if one titled the spinbox 'Water density“?

I will change the UI accordingly.

> <planner1.xml>

Best
Robert

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