[datatable-help] Odd behavior with [.data.table and J

[Christian Hudon]

>
> I see what you mean, thanks for following up. J was an alias for
> data.table at some point, maybe up to quite recently. Might have changed
> in 1.8.0.
>
> I'm leaning towards making J() work again as you expected it to, then.
> Consistent with it being an alias for data.table, so documentation doesn't
> need to change. With fresh eyes, it seems like a bug now.
>
> If nobody on the list objects, please raise a bug report.
>

Here is the bug report:
https://r-forge.r-project.org/tracker/index.php?func=detail&aid=2265&group_id=240&atid=975

While we're talking about behavior that changed in recent versions, is
there any reason why recent versions of data.table give a warning when used
with factor columns (for joins)? I know these things are not a problem for
people who use exclusively data.table everywhere, but we have a mix of
data.table and data.frame objects in our code (for various reasons)... so
we can't really convert to strictly string columns. Actually, I don't
really see the reason for this warning, as everything works fine even with
factor columns.

For data.table and data.frame interoperability, it would also be useful if
setnames worked on data.frames.

Thanks,

  Christian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.r-forge.r-project.org/pipermail/datatable-help/attachments/20120907/8d740bcf/attachment.html>