Distances with missing values

[bdeonovic]

I saw this issue on DataFrames (JuliaData/DataFrames.jl#183), and noted that it was from a few years ago. Is there support for missing values in Distances.jl yet?

[johnmyleswhite]

No, there is not. Pull requests would be reviewed I'm sure, although I imagine that Distances.jl shouldn't depend upon DataArrays.

[lindahua]

I think supporting missing value is not in the scope of this package (at least at this point).

[oxinabox]

We should come back and do this now that Missing data handling is in Base.

[KristofferC]

There should be no need for special handling of Missing here.

Agreed with #11 (comment)

[rofinn]

FWIW, I found a specific use case where supporting missings here would help the larger ecosystem. Specifically, Distances.jl -> NearestNeighbors.jl -> Impute.jl.

invenia/Impute.jl#141 (comment)

Impute.jl isn't getting a lot of active development anymore, so I understand if it isn't worth the change, but updating Distances.jl and NearestNeighbors.jl seems like the best approach.