[R] deleteing all but some observations in data.frame

[Erik Iverson]

Note that these methods don't 'delete' observations.
They all create brand new objects that are
subsets of the test.df object.  You can effectively
'delete' the observations by replacing the original
data.frame with the returned object...

so

test.df <- head(test.df, 20)


Erik Iverson wrote:
> It depends on which 20 you want.
> 
> If you have a data.frame called 'test.df', you can do:
> 
> #first 20
> test.df[20, ]
> 
> -or-
> 
> head(test.df, 20)
> 
> #random 20
> test.df[sample(nrow(test.df), 20), ]
> 
> None of this was tested, but it should be a start.
> 
> --Erik
> 
> Matevž Pavlič wrote:
>> Hi,
>>  
>>
>> I am sure that can be done in R....
>>
>> How would i delete all but let say 20 observations in data.frame?
>>
>>  
>>
>> Thank you, M
>>
>>  
>>
>>  
>>
>>
>>     [[alternative HTML version deleted]]
>>
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> 
> ______________________________________________
> R-help at r-project.org mailing list
> 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.