Distinguish between bad data and no data

[lucas-wilkins]

The interpretation of points within reduced data depends somewhat on whether there has been a bin there that is removed, or just no data. Keep track of this.

[butlerpd]

Can you elaborate a bit about what is meant here? It would seem that this is what our "masks" are? Or is this about the fact that masked data is not uniformly handled throughout the package (i.e. sometimes ignored and other times not)?

[butlerpd]

Working on cleanup in preparation for Contributor Camp XII:

Actually I see @lucas-wilkins and @krzywon that masks are not currently part of the data objects but that the data object restructure is meant to fix that? If so does this mean this is a duplicate ticket?