I agree. On Sep 14, 2016 5:54 PM, "Douglas Bates" <[email protected]> wrote:
On Wednesday, September 14, 2016 at 4:42:39 PM UTC-5, tshort wrote: > > For avoiding unwanted conversions, DataFramesMeta has a PassThrough type > with an alias P. You should be able to do: > > mydf[1] = P(Array(mydf[1])) > True but the approach has a bit of a "burning the toast and then scraping it" feel to it. (That was a favorite expression of Deming's re quality control.) I think it would be better for setindex! in a DataFrame to skip the conversion to a DataArray or a NullableArray. > > On Sep 14, 2016 5:17 PM, "Douglas Bates" <[email protected]> wrote: > >> Of course, this brings me back to another problem, which is replacing a >> column of a dataframe with an Array without having the Array converted to a >> DataArray or a NullableArray. I have a large CSV file in which over 99% of >> the columns do not contain nulls. Because some of the columns contain >> nulls I can't use CSV.read(..., nullable = false) but I do want to convert >> those columns that do not contain nulls to Arrays. >> >> If I try to replace the column as >> >> mydf[1] = Array(mydf[1]) >> >> I get a DataArray in the release version of DataFrames. (I'm not sure >> what happens in your nl/nullable branch). >> >> The way I avoid this is right now is by working with mydf.columns >> directly but I always caution others not to work directly with fields of >> composite types and I should probably follow my own advice. >> >> On Wednesday, September 14, 2016 at 4:07:21 PM UTC-5, Douglas Bates wrote: >>> >>> Thanks. I didn't try that because I thought that a NullableArray was an >>> Array so that conversion would be a no-op. I should have tested it. >>> >>> On Wednesday, September 14, 2016 at 4:02:04 PM UTC-5, Milan >>> Bouchet-Valat wrote: >>>> >>>> Le mercredi 14 septembre 2016 à 13:56 -0700, Douglas Bates a écrit : >>>> > I remember someone (Milan?, Alex?) writing a short cal to convert a >>>> > NullableArray to an Array but I can't seem to find it now. Can >>>> > someone refresh my memory, please? >>>> What do you mean exactly? This works AFAICT: >>>> julia> convert(Array, NullableArray(1:3)) >>>> 3-element Array{Int64,1}: >>>> 1 >>>> 2 >>>> 3 >>>> >>>> >>>> Regards >>>> >>> -- >> 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. -- 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.
