[R] Sample on dataframe

[Prof Brian Ripley]

All that is needed is

my.df[sample(nrow(my.df), size=<whatever>), ]

On Wed, 23 Jul 2008, milton ruser wrote:

> I hope this helps
>
>
>
>
> my.df<-read.table(stdin(), head=T, sep=" ")
> V5 V5.1 V5.2 V5.3 V5.4 V5.5
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
> -5890.18905 -6019.84665 -6211.06545 -6198.9353 -6616.8677 -6498.7183
>
> number.of.records<-5
> my.df.subset<-my.df[sample(1:dim(my.df)[1], size=number.of.records,
> replace=F),]
> my.df.subset
> You can change "replace" by T if you allow repeat rows.
>
> Cheers,
>
> miltinho astronauta
> brazil
>
>
>
>
>
> On 7/23/08, Jarekj <jarekj at amu.edu.pl> wrote:
>>
>> Hi
>> I'm looking for solution or function which I can use to sample data frame,
>> to obtain new (smaller) data frame similar to sample() function
>> Jarek Jasiewicz
>>
>> ______________________________________________
>> 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<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
> 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.
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595