From JDiveLog to Subsurface

Linus Torvalds torvalds at
Mon Oct 31 10:45:24 EDT 2011

On Mon, Oct 31, 2011 at 7:04 AM, Jef Driesen <jefdriesen at> wrote:
> The Suunto Vyper series only stores the temperature and tank pressure before
> and after the dive, and also the temperature at the maximum depth.

I didn't even realize that they were air-integrated at all. At least
giving the start/end pressure is better than not having it at all.

The jdivelog file doesn't seem to have those pressures, though - at
least not in a format that looks like it came from a dive computer.
The pressures it has seem to be entered by hand, because they are so
round (eg "PSTART 2.2E7, PEND 8000000" - almost certainly in pascal,
and thus looks very much like 220 bar down to 80 bar to me, and is
unlikely to be a computer reading).

> You can easily notice this when you click the recalculate button in the Air
> Consumption tab. It will ask you whether to simulate or not. Depending on
> whether you answer yes or no, SDM will interpolate the pressure linearly
> (and thus a non constant SAC graph), or interpolate the pressure assuming a
> constant SAC (and thus a non linear pressure graph). Note that SDM will ask
> this question only once (per dive), and you can't undo your choice as far as
> I know.

Ok. We always interpolate pressures with a constant-SAC model, and
paint the interpolated line in yellow (while actual samples are in


More information about the subsurface mailing list