Thank you everybody, problem solved! :)
David Winsemius wrote:
>
>
> > read.table(textConnection(gsub("\\(|\\)", "", var) )) #from prior
> posting
> V1 V2
> 1 p1 10
> 2 p1 3
> 3 p1 4
> 4 p2 20
> 5 p2 30
> 6 p2 40
> 7 p3 4
> 8 p3 1
> 9 p1 2
>
> > ridxs <- sample(1:nrow(df),floor(0.7*nrow(df)) ) # the 70% sample
> row IDs
>
> > df[ridxs,]
> V1 V2
> 5 p2 30
> 6 p2 40
> 2 p1 3
> 7 p3 4
> 4 p2 20
> 8 p3 1
> >
> >
> > df[-ridxs,]
> V1 V2
> 1 p1 10
> 3 p1 4
> 9 p1 2
>
> The terms to pay particular attention to in the introductory material
> are row indexing, dataframe, and negative indexing of dataframes.
>
>
>
> On Jan 18, 2009, at 12:35 PM, S.Putoto wrote:
>
>>
>> Hello dear R Users,
>>
>> I am working on a dataset of 928 Enterprises, of which are observed 12
>> different characters. I need to randomly sample, without repetition,
>> 70% of
>> the entreprises, to create a testing set, and let the other 30% of the
>> enterprises be a validating set (holdout validation, I think that
>> is). How
>> do I do that? Of course all the characters of each row must remain
>> together.
>> Also, I am not very familiar with the R-Base language (it is the
>> first time
>> I use it) so if You could also explain to me what every function and
>> argument means, it would be great help to then reiterate the
>> procedure.
>
> Really! Don't you that is a bit much? There are many tutorials
> available on line. The terms to pay particular attention to in the
> introductory material are indexing, dataframe, and negative indexing
> of dataframes.
>
> --
> David Winsemius
>
>>
>>
>> Thank You very much,
>>
>> Sebastiano
>> --
>> View this message in context:
>> http://www.nabble.com/Extracting-random-rows-from-a-dataset-tp21530539p21530539.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help@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.
>
> ______________________________________________
> R-help@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.
>
>
--
View this message in context:
http://www.nabble.com/Extracting-random-rows-from-a-dataset-tp21530539p21535138.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
R-help@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.
