It seems to me that contrasts should be defined in defined in the array packages and not in DataFrames. We'd probably need the functions to be defined in an upstream package like StatsBase or (ArrayBase/DataBase?) such that all array packages can extend them.
We have the usual problem of optional dependencies. Should DataFrames depend on any data array package or all of them? Is it possible the DataFrames doesn't use any features of concrete data array types and only define methods for abstract types? Then the user would have to load a specific array package. This might be a bit demanding to keep working and from a user perspective, a single good implementation might be better. What are the specific issues you are having right now? Are the things that are broken things that used to work or is work in progress towards using Nullable and Categorical arrays? On Tue, Jul 19, 2016 at 12:23 PM, Douglas Bates <[email protected]> wrote: > Yes, thanks to Tony, Andreas, Milan and others who worked on this. > > At the risk of making myself unpopular I would like to return to the issue > of ModelFrame, ModelMatrix, etc. because a lot of code is still broken for > me. At present `DataFrames/REQUIRE` lists `DataArrays 0,3.4` but neither > `NullableArrays` nor `CategoricalArrays`. Contrasts are defined in > `DataFrames/src/statsmodels/formula..jl` but we would need to require > `CategoricalArrays` if contrasts for that type were to be defined there. > To me it would make more sense to define the contrasts where the array > types are defined. > > I can add `CategoricalArrays` to `DataFrames/REQUIRE` to get ModelMatrix > working again but that might have a knock-on effect for many packages that > require `DataFrames`. > > Although I'd really like to get ModelMatrix working again, I don't want to > make changes like DataFrames requiring CategoricalArrays that later need to > be backed out. > > -- > You received this message because you are subscribed to the Google Groups > "julia-stats" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "julia-stats" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
