[R] Group by in R

[Gabor Grothendieck]

SQL has the order by clause.

On Mon, Apr 13, 2009 at 7:26 AM, Nick Angelou <nikolay12 at yahoo.com> wrote:
>
> Thanks a lot, guys. Gabor's and Mike's suggestion worked. Duncan's did not do
> exactly what I expected (I guess it's the "paste" in Mike's that makes
> "table" work as I needed it).
>
> One more question - is there a convenient way to order the group by results
> as follows:
>
> As rows: the unique combinations of factors f1, f2, f3, as columns the
> unique values of f4. The counts are basically the same as of the GROUP BY
> statement (or the paste and table combination suggested by Mike).  Only the
> way the result is structured is different.
>
> Thanks,
> Nick
>
>
> Nick Angelou wrote:
>>
>> Hi,
>>
>> I have the following table data:
>>
>> f1, f2, f3, f4.
>>
>> I want to compute the counts of unique combinations of f1-f4. In SQL I
>> would just write:
>>
>> SELECT COUNT(*) FROM <table> GROUP BY f1, f2, ..,f4.
>>
>> How to do this in R?
>>
>> Thanks,
>>
>> Nick
>>
>
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