[R] select rows with identical columns from a data frame

Sam Steingold sds at gnu.org
Sun Jan 20 17:26:44 CET 2013


> * Bert Gunter <thagre.oregba at trar.pbz> [2013-01-19 22:26:46 -0800]:
>
> But David W. and Bill Dunlap gave you solutions that also work and are
> much faster, no?!

Yes, indeed, and I am now using David's solution as it is fast
(enough), simple and concise.

Thanks a lot to David, Bill, Rui, and arun for their answers (to this
question, my many previous questions, and, I hope, my future questions
in advance)!

> On Sat, Jan 19, 2013 at 9:41 PM, Sam Steingold <sds at gnu.org> wrote:
>>> * Rui Barradas <ehvconeenqnf at fncb.cg> [2013-01-18 21:02:20 +0000]:
>>>
>>> Try the following.
>>>
>>> complete.cases(f) & apply(f, 1, function(x) all(x == x[1]))
>>
>> thanks, this works, but is horribly slow (dim(f) is 766,950x2)

-- 
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