[R] how to randomize a vector

leffgh leffgh at 163.com
Mon Nov 12 08:45:14 CET 2007





oh, thank you ,
I used the "sample"function to generate new subordinates 
but never think that it can directly act on the vector .
thank you very much.


Frede Aakmann Tøgersen wrote:
> 
> Why didn't you do this in R?
> 
>> help.search("random sample")
> Help files with alias or concept or title matching 'random sample'
> using fuzzy matching:
> 
> 
> 
> sample(base)            Random Samples and Permutations
> 
> 
> 
> Type 'help(FOO, package = PKG)' to inspect entry 'FOO(PKG) TITLE'.
>> 
> 
> See ?sample, e.g.
> 
>> t1 <- rnorm(70000)
>> system.time(t2 <- sample(t1,size=length(t1)))
>    user  system elapsed 
>    0.01    0.00    0.01 
> 
> 
> Best regards
> 
> Frede Aakmann Tøgersen
> Scientist
> 
> 
> UNIVERSITY OF AARHUS
> Faculty of Agricultural Sciences
> Dept. of Genetics and Biotechnology
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> 
> Phone:   +45 8999 1900
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> 
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> 
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>  
> 
>  
> 
>> -----Oprindelig meddelelse-----
>> Fra: r-help-bounces at r-project.org 
>> [mailto:r-help-bounces at r-project.org] På vegne af leffgh
>> Sendt: 12. november 2007 07:50
>> Til: r-help at r-project.org
>> Emne: [R] how to randomize a vector
>> 
>> 
>> I have a vector whose length is nearly 70 thousand.
>> I need randomize it for 1000 times .
>> for randomizing , I mean ,the elements of the vector remain 
>> intact while their order in the vector get changed randomly.
>> I have written a function which seems to be able to solve 
>> short vectors , but waste  a lot of time when dealing with 
>> the the long vector mentioned above.
>>  
>> --
>> View this message in context: 
>> http://www.nabble.com/how-to-randomize-a-vector-tf4789292.html
>> #a13700770
>> Sent from the R help mailing list archive at Nabble.com.
>> 
>> ______________________________________________
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>> http://www.R-project.org/posting-guide.html
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>> 
> 
> ______________________________________________
> R-help at r-project.org mailing list
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> 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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