issue_comments: 794715751

How do you linearly interpolate strings, objects or booleans?

The problem for me is that we drop all the non-valid variables when I want linear interpolation for most of my stuff. One can argue it could be either of bfill, ffill or nearest but I chose nearest because that's an option for both missing.interp and reindex_variables. I suppose we can add it as an option? But what should the option be called when we want a backup interpolation method that does not modify the elementwise values? And should it then only be reindex_variables specific?

Another case I've been pondering how to handle is when numbers are used as IDs. Then it doesn't make sense to do interpolation that messes with the elements as well. But these integers are not easily determined though because you can use integers just for performance reasons and then wouldn't mind it becoming floats later. Maybe they will continue staying a special case.