[datatable-help] variable column names

[Victor Kryukov]

On Fri, Apr 26, 2013 at 3:47 PM, Matthew Dowle <mdowle at mdowle.plus.com> wrote:
> On 26.04.2013 23:02, Sam Steingold wrote:
>>> http://stackoverflow.com/questions/16241687/summarize-a-data-table-across-multiple-columns
>>
>> downvoted, unlikely to be answered.
>
> I've read it through.
>
> Perhaps sleep on it, don't look for 24hrs and look again as if you were
> trying to answer it yourself. Are there any small changes you can make to
> make it easier to answer?  It wasn't me that downvoted but I suspect it's
> been done to encourage you to improve the question. Downvotes can (and often
> are) reversed.  I've had many more downvotes than you once, but then I
> improved it and it went to +10.
>
> And, it's Friday and we've all had a long week!

Beautiful advice, Matthew!

Sam - I've provided my answer (and even used Reduce since you seem to
be coming from Lisp land), but I also think some of the down
votes/comments have their merit.