[R] How to view un-sampled data from a randomly sampled dataset

[William Dunlap]

> s <- sample(1:nrow(data), 40, replace=FALSE)
> y <- data[s,]
> x <- data[-s,]

If you don't know the size of the sample and it might be 0 then
you have to be a bit more wordy:
    x <- data[setdiff(seq_len(nrow(data)), s), ]
or the uglier
   x <- if (length(s) > 0) x else x[-s,]

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
> Of peter dalgaard
> Sent: Wednesday, October 23, 2013 12:37 PM
> To: erinu
> Cc: r-help at r-project.org
> Subject: Re: [R] How to view un-sampled data from a randomly sampled dataset
> 
> 
> On Oct 23, 2013, at 20:13 , erinu wrote:
> 
> > Hi there-
> >
> > I have a 150 row dataset (data). I create "y" a randomly sampled (without
> > replacement) set number of observations (40):
> >
> > y<-data[sample(1:nrow(data),40,replace=FALSE),]
> >
> > I would like to make a new variable "x" that contains the leftover
> > non-sampled 110 observations.  I am sure there is a fairly easy way to do
> > this.
> >
> > Any help would be greatly appreciated.
> >
> > THANKS!
> >
> 
> Just hold on to the indices:
> 
> s <- sample(1:nrow(data), 40, replace=FALSE)
> y <- data[s,]
> x <- data[-s,]
> 
> -pd
> 
> 
> >
> >
> > --
> > View this message in context: http://r.789695.n4.nabble.com/How-to-view-un-
> sampled-data-from-a-randomly-sampled-dataset-tp4678887.html
> > Sent from the R help mailing list archive at Nabble.com.
> >
> > ______________________________________________
> > 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
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> 
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com
> 
> ______________________________________________
> R-help at r-project.org mailing list
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> and provide commented, minimal, self-contained, reproducible code.