Right, if you read the rest of my rambling, I think they're using the per-sample "exertion level" -- which is derived by the computer from air consumption -- and using that along with the total consumption to fake a curve.

I do want to see if I can get that total consumption number imported into subsurface.

On Wed, Mar 18, 2015 at 9:13 AM, Jef Driesen <jef@libdivecomputer.org> wrote:

On 2015-03-18 15:30, Shawn Willden wrote:

Hmm. Looking at the Aladin and Memomouse pages there certainly doesn't seem
to be any place for tank pressure. But DataTrak *does* display it.

They might be cheating. There appears to be a field with the total air consumption. DataTrak might be using that to interpolate the air consumption during the dive and generate a fake graph.

Suunto does this too for their older models (the vyper family). It's very confusing for users. They assume the graph is generated from real data, and wonder why libdivecomputer based applications don't show it. This is actually one of the most common question I receive.

The libdivecomputer api does support begin/end tank pressure. I assume that the Aladin's total air consumption value is the difference between the end and begin pressure. Unfortunately that's not enough info for libdivecomputer.

Jef

Shawn