[datatable-help] Unexpected behavior in setnames()

[Steve Lianoglou]

Hi,

On Sat, Nov 2, 2013 at 8:41 AM, Arunkumar Srinivasan
<aragorn168b at gmail.com> wrote:
[snip]
> Overall, I agree keeping duplicate names may help some users. But then, the
> potential side-effects should be marked with warnings/errors distinctly, in
> all cases (and preferably documented).
[/snip]

I guess I must have missed it, but has anyone anywhere (in this
thread, a FR or something) actually present a (concrete) compelling
situation where allowing duplicate column names was actually useful?

I'm hard pressed to come up with any situation where (purposefully)
keeping duplicate column names in a data.table has more benefit than
downside. Seems to me that if this ever happens, it most certainly
would be by mistake.

Can someone help me out here?

In the case of cbinding two data.tables together that end up having
two duplicate names, I'd imagine unique-ing the names of the
data.tables and firing a warning that this was done would be most
useful (uniqueness priority would be from left to right as the
data.tables are passed into the cbind call)

-steve

-- 
Steve Lianoglou
Computational Biologist
Bioinformatics and Computational Biology
Genentech