@wkerzendorf @eteq Hi Erik and Wolfgang, just wanted to pull your attention to this. This error came up when I was trying nddata out while working on the ccdproc package. It looks good to merge, but I could also think that someone would want to fix it in another way

@crawfordsm I should warn you however that the nduncertainty part of nddata is not stable and is likely being revised with an uncertainty formalism that pertains to both Quantity and NDData.

As for this PR, I need to have a look through, referencing potentially big arrays from another class is sometimes a recipe for memory leaks.

Thanks @wkerzendorf ! Please definitely check it out. I understand things will be updating but the current divide and multiple in stduncertainity were not working due to calling self.data that didn't exist. Also, _parent_nddata was never being assigned. So there were the only two things I updated so that it did actually work. However, I definitely understand there might be a better way to do this and I'm happy to open up an issue and delete this PR if there is a better way

I think this is exactly what was intended, it's just a bug, because the uncertainty shouldn't have a .data. I don't think this is a memory leak any more than the whole idea of NDUncertainty is. So unless @wkerzendorf specifically says this isn't supposed to work this way, I'll merge this soon.

@eteq I think for now it's fine. As discussed in the meeting, the treatment of uncertainties will require a good amount of effort on multiple fronts. However, small implementation like this might teach us how its used. Thanks for looking into this @crawfordsm!

Great, I'll go ahead and merge this, then. Thanks @crawfordsm !

Hadn't noticed this before--it should have been backported to the 0.2.x branch, but that's okay. In the remote chance that it becomes required we can backport it, but that seems doubtful once 0.3 is out.