Gas Management

[bvanant]

Just loaded three dives into Macdive (2.1.3). Put the correct tank into the gas management tab (I think) but SAC rate is 0. (Suunto D9). There are boxes to enter starting and ending pressures but do I have to enter all that manually for 1500 dives? The air pressure data is there but the starting and ending pressure data all say 0 on the summary page. What gives?
thanks
Bill

To be clear, the SAC rate graph shows up but in the gas management page it is all zeroes as it is in the Summary page
Bill

[nick]

Have you read the help for Gas Management which describes how to make your SAC work? Does your tank have a Size set? Does it have a working pressure if you use Imperial units?

The easiest thing to do is send me your data file, and a detailed description of which dive (one is fine) is not showing the SAC. I will take a look and see what is going on.

But the most likely problem is that you are missing required information, as explained in the help.

[bvanant]

Nick: I guess that I wasn't clear enough. In the main page (where the dive profile shows up) the air pressure data is there and the SAC data is there as well at least there is a graph. But in the summary page for the individual dive the SAC and all at the pressure data show zero. Clearly the gas management page is set up correctly (since the data shows up on the main page) but there is a different issue. I think what I will try is to erase the dives and re-import them, something clearly happened at import. I will let you know what is going on if the problem persists.
Bill

[nick]

The gas management was a fairly complex change to MacDive, so there is every chance something is not quite right.

Email me your data, as it's very difficult to debug this issue without seeing it.

[bvanant]

Well it gets more interesting. I deleted the last 5 dives from the D9 and reimported them with no issues. Everything looks fine. There are still a couple of Cobra dives that seem wrong but I will reimport and let you know.
The new gas management is indeed quite nice, I like it a lot.
BIll

[tmm]

I'm having a some confusing SAC #'s showing in the dive inspector that I'm trying to figure out what I'm doing incorrectly on manually entered dives.. On the summary screen my correct SAC is shown, but on the Gas Management screen my SAC is an entirely different value and it's showing Avg Depth to be 0, yet in the More tab, the Avg Depth is showing 40. I have my tank info entered correctly as far as I can tell and have the tank added to the gear for the dive.

Screen caps attached and thanks for your help.

[nick]

The SAC is calculated a little differently in various circumstances -

When you are looking at the gas management panel, the SAC is calculated based on the average depth of that tank, for the profile points it relates to. So when you have manually entered a dive, there is no profile points - therefore the average depth is 0. This is throwing it off.

In the overall view, the actual average depth of the dive can be used if there are no tanks. But the SAC rate for that tank is theoretically correct. I hope this makes sense?

What I could probably do is add some more logic in there, so that if this dive has no profile then the overall average depth of the dive is used in place of the actual average depth. That should return the same value, and make more sense.

[tmm]

Wow, that was quick....

Thanks for the explanation. It's good to know that those results aren't as a result of me having something entered incorrectly.

if this dive has no profile then the overall average depth of the dive is used in place of the actual average depth

I like that idea.... a little less confusing

Oh, and I know this should go in the Requests forum, but any plans for a scroll zoom in/out on the map view?

[nick]

Ok. Let me look in to tweaking that, I'll hopefully have time to fix that tonight. Could you do me a favour, though, and email me a copy of your MacDive.sqlite data file? Would be good to test against your actual data to confirm the values look correct. Then I can send you a beta to try.

I'll look in to the map scroll too.

[tmm]

On it's way!