Importing from two computers with air pressure sensors

Linus Torvalds torvalds at
Fri Jun 12 13:07:07 PDT 2020

On Fri, Jun 12, 2020 at 1:01 PM Richard Houser via subsurface
<subsurface at> wrote:
> Would this be a simple enough check?:
> IF (start/end pressure are BOTH within X% of an existing cylinder) THEN treat as the same, ELSE add as new?

We could change our heuristics, but part of it is that we very much
have treated dive computers as being redundant by default in general.

IOW, the primary reason to have two dive computers is not to track
four cylinders (if you cared about that, you'd get something else than
a Shearwater!) but for redundancy.

So redundancy not just for cylinder pressure, but in general. If one
dive computer stops working, the other one still does all the same
things and you still have a fully working setup.

And the reason the pressure testing is a bit questionable is that we
really have real-world examples of bad pressure data. I have several
dives with a dive computer where the pressure sensor stopped working
in the middle. So the start/end pressure aren't both within some tight
percentage band.

So it would have to be some rather more complex thing.

Or maybe some simple flag at download time to simply say "treat
cylinders as separate". Except that involves GUI issues, and that in
turn ends up having its own set of horrible problems, both for coding
and for confusing users.


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