[R] sorting a dataframe

Bert Gunter bgunter.4567 at gmail.com
Sun Jun 21 19:52:55 CEST 2015


Diego:

Nonsense! Look at the results of your code -- you have failed to order
the results as had been requested by the OP. It's also unnecessarily
complicated. The following suffices (where I have used regular
expressions rather substring() to get the numeric part of the strings
-- **assuming** that the strings always consist of letters followed by
numeric digits).

> A = c("A1","A10","A11","A2")
>  B = c(1,2,3,4)
>  dat = data.frame(A,B)
>
> numbs <- as.numeric(gsub("[^[:digit:]]+","",dat$A))
> newdat <- dat[order(numbs),]
> newdat
    A B
1  A1 1
4  A2 4
2 A10 2
3 A11 3

Cheers,
Bert



Bert Gunter

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
   -- Clifford Stoll


On Sat, Jun 20, 2015 at 6:29 PM, Diego Miro <d.miro1089 at gmail.com> wrote:
> Bogdan,
>
> Follow my suggestion.
>
> letter <- substring(A, 1, 1)
> number <- substring(A, 2, nchar(A))
> new.data <- paste0(letter, formatC(as.numeric(number), width = 2, flag =
> "0"))
> Em 20/06/2015 21:21, "Bogdan Tanasa" <tanasa at gmail.com> escreveu:
>
>> Dear all,
>>
>> I am looking for a suggestion please regarding sorting a dataframe with
>> alphanumerical components :
>>
>> let's assume we have :
>>
>> A = c("A1","A10","A11","A2")
>> B = c(1,2,3,4)
>>
>> C = data.frame(A,B)
>>
>> how could I sort C data.frame in such a way that we have at the end :
>>
>> C$A in the order : "A1", "A2", "A10", "A11". thank you very much,
>>
>> -- bogdan
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> 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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