On 18 Aug 2015 12:13 am, "Jan Darowski" <[email protected]> wrote: > > > I think I've worked out at least one difference in the programs' algorithms, > > and sorry I doubt you'll like it. Subsurface calculates required stops > > considering the ascent rate and the time to reach the stop. The Fortran > > program calculates the 'instantaneous' ceiling, i.e. the depth corresponding > > to the tolerated ambient pressure according to the current allowable > > pressure gradient. More fun! > > > > Which approach is more justified? Debatable. The method used by Subsurface > > should be 'better', but when the depth of the first stop/ceiling is given a > > special significance thanks to the Boyles law compensation process, I'm not > > so sure. The 'instantaneous' ceiling method is more conservative, and, > > without having modified the code and tested, I'm guessing would produce deco > > schedules more consistent with other VPM-B programs. > > > > R > > > > I expected something like this... calculations are checked, gradients > are checked. It had to be something "mechanical". For the examples > you've posted I got 16 vs 16min and 46 vs 49min after the fix (in > trial_ascent I changed the segment time to 0 and added one more place > for boyles_compensation). > > Thanks a lot for this, I spent many days on searching for bugs in this > code. I suppose there can be some other small issues but this one > explains a lot. > > Today there will be a patch for this. >
Great, I'm glad it wasn't too painful. Make sure not to break the current method for the Buhlmann model. That works well as it is. > -- > Jan Darowski
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