[R] inadverted reordering of a df column when it is copied to another df

Rui Barradas ruipbarradas at sapo.pt
Fri Mar 17 18:53:58 CET 2017


Hello,

Not an answer to the OP's statement, but

 > class(1L:40000L)
[1] "integer"
 > class(1:40000)
[1] "integer"

When using m:n there's no need for mL  or nL.

Rui Barradas

Em 17-03-2017 16:58, Jeff Newmiller escreveu:
> Reprex confirming Bert:
>
> A <- data.frame( y = 1L:40000L )
> B <- data.frame( x = 1L:40000L )
> A$x <- B$x
> plot(B$x)
>
> #' ![](http://i.imgur.com/cXSFsBh.png)
>
> Care to demonstrate for us, Karl?
>
> https://cran.r-project.org/web/packages/reprex/README.html
>
> On Fri, 17 Mar 2017, Bert Gunter wrote:
>
>> You are wrong. No reordering occurs.
>>
>> Cheers,
>> Bert
>>
>> Bert Gunter
>>
>> "The trouble with having an open mind is that people keep coming along
>> and sticking things into it."
>> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>>
>>
>> On Fri, Mar 17, 2017 at 8:05 AM, Karl Schilling
>> <karl.schilling at uni-bonn.de> wrote:
>>> Dear all:
>>>
>>> I have two data.frames A and B of the same number of rows (about
>>> 40,000). I
>>> realized that when I copy column x from data.frame A to B, the order
>>> of this
>>> column  gets changed. This seems to affect only values in rownumbers > ~
>>> 35/36,000. It also happens in any of the following three approaches:
>>>
>>> A$x <- B$x
>>>
>>> x <- B$x (here, x is still in the correct order)
>>> B$x <- x : now x is reordered
>>>
>>> B <- cbind(A, B$x)
>>>
>>> I am working with Windows7Pro/64bit, R 3.3.3, and RStudio 0.99.903.
>>>
>>> Any help would be appreciated.
>>>
>>> Best regards
>>>
>>> Karl Schilling
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
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> ______________________________________________
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