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Jody Svendsen sez: > Just a nit-pick; MiG Plan generates tables based on the Huggins and > Buhlmann algorithms. It is not accurate to say this person was bent on > MiG Plan; he was bent on Buhlmann tables. Some of the other programs have > made changes to the models, and in these cases it may be somewhat accurate > to say that a person was bent on them. MiG Plan develops tables > faithful to the original design of the models, and therefore deserves > neither credit nor blame for the reliability of its output. > Jody Svendsen > MiG Technologies This is rather more than a little bit hard to swallow: are you trying to imply that as a software vendor you have no responsibility for any results of using your product??!! So I suppose then that you advertise your product as simply being an electronic Buhlman table, and not a product which generates decompression schedules? NOT! Lets go over some problems with this, shall we? o Buhlman has never claimed that his research was to be used the way tech divers currently use it: as a straight algorithm to generate deco schedules for real-world diving. Somehow, I get the feeling that you do not properly relate this to your clients... o The straight Buhlman algorithm lacks conservativeness, and has been responsible for many cases of DCI. If you somehow add conservatism to the algorithm, you are then no longer producing even a version of the Buhlman algorithm, but rather a one-off deco algorithm which is completely untested and unproven. o The entire notion of "adding conservatism" is a rather interesting area to explore: how are you sure that the modifications you made to the Buhlman algorithm actually do increase conservatism (and therefore safety)? Did you test them? Is more decompression time always more conservative? Can you prove this? Oh wait, I forgot: you are not responsible for the outcome of using your software! o How do you know that the output of your program is actually faithfull to the Buhlman algorithm? Can you prove your implementation of the Buhlman mathematics rigorously? Do you test your software with the naieve approach of running some number of known dives, or do you actually do something more sophisticated? Remember, people are trusting their life to your software -- but of course, you deserve neither credit nor blame for the reliability of the output, right!! (NOT!) o How would you feel about this situation: Boeing produces a new, computer controlled plane, but they use the fly-by-wire algorithms developed by Airbus. Rather than subject the plane to rigorous testing, they simply claim that their implementation is faithful to the original algorithm development done by Airbus, so Boeing bears no responsibility. Would you fly in that plane? Would you insure it? o Adaptations of the Buhlman algorithm for Trimix diving are hacks which have never been supported by Buhlman. o The Buhlman *tables* are just that: tables. The *tables* have built-in rounding which makes them inherently different than the Buhlman *algorithm*. Unless your software is simply doing table lookup, it does *not* generate the Buhlman *tables*. -frank -- fhd@in*.ne* | [M]athematics is not the study of intangible Platonic 1 212 559 5534 | worlds, but of tangible formal systems which have arisen 1 917 992 2248 | from real human activities. 1 718 746 7061 | -- Saunders MacLane
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