[PATCH] Import surface event from Suunto DB

[Miika Turkia]

On Tue, May 19, 2015 at 9:43 PM, Linus Torvalds
<torvalds at linux-foundation.org> wrote:
> On Tue, May 19, 2015 at 11:36 AM, Robert C. Helling <helling at atdotde.de> wrote:
>>
>> On 19 May 2015, at 18:22, Miika Turkia <miika.turkia at gmail.com> wrote:
>>
>> Miika,
>>
>>> This is actually relevant information when someone surfaces
>>> accidentally, thus we should not ignore it.
>>
>> maybe this event should also trigger a zero depth sample. What do you think?
>
> I think Suunto (and probably others) considers "surface" to be 3ft,
> not zero. I've seen "lots of surface events" when I do a swim back to
> shore, and I think it would actually look bad if it made the profile
> jump back-and-forth between 4ft and 0ft for that use case. It may not
> be horribly common, but I don't think it's necessarily all that
> unusual either.
>
> It might be interesting to see what the samples around it are, and
> maybe also take sample rate into account. With a 30s sample rate, I
> certainly agree that losing a surface event in between just because
> you went up and immediately back down again is a misfeature. But with
> a 10s sample rate and the samples around that time being 4ft, I think
> it would be wrong to say "0ft" in between, because that really isn't
> what the event even means.
>
> The reason we mask out that event is really that it can get very
> annoying in that "shallow swim out or back" scenario for shore diving.
> Maybe other people really tend to swim at the surface, and I'm just
> odd for liking to do the "shallow dive back" thing. But clearly it was
> wrong to ignore it *entirely*, and we should do something more subtle.

You both do make sense. If someone bounces to surface and then
descents back to diving depth, an added 0 depth sounds like sensible
thing to do. Especially if we keep masking the surface events. How
about, if max depth after the surface event is more than 1 meter, add
depth 0 for the event time? Or would a test for before and after
depths be better?

For those interested in background information, the last comment on
this discussion
https://groups.google.com/forum/#!category-topic/subsurface-divelog/ccUACNKv6AQ
triggered the whole change. But of course I am not tackling the
reported issue with this patch but only Suunto DM import.

miika