No,even there's only one observation,boxplot can still be drawn.

x<-1
boxplot(x)

or
x<-1:3
boxplot(x)
...




2011/3/9 Dennis Murphy <djmuser@gmail.com>

> Hi:
>
> A box plot is based on a five number summary, so you need at a minimum five
> observations (and preferably at least twice that) to make a box plot a
> viable summary measure for a continuous variable. Consider other graphical
> summaries for these data - perhaps a strip chart or a simple scatterplot.
>
> HTH,
> Dennis
>
> On Tue, Mar 8, 2011 at 9:26 PM, Gaurav Kumar <gaurav@gauravkumar.org>
> wrote:
>
> > Dear R-user,
> >
> > I'm facing problem to draw boxplot. I can draw my
> > boxplot but the space option is not working for me. I've no clues where
> > i'm doing wrong
> > my data is as matrix as shown below:
> >         [,1] [,2]
> > [1,]   98  60
> > [2,]   96  70
> > [3,]   95  80
> >
> > and i'm plotting as
> > barplot(height=c(data[1,],data[2,],data[3,]),
> >       beside=TRUE,
> >           space=c(.1,1),
> >           border="black",
> >           col=c("blue","red") )
> >
> > Please help me where i'm doing wrong or some known issue is there with
> > boxplot.
> >
> > Thanks in advance.
> >
> > Gaurav Kumar
> > www.gauravkumar.org
> >
> > PhD Student, Chemistry and Biomolecular Sciences, Macquarie , Sydney,
> > Australia.
> > MS (Computational Biology), NCBS-TIFR, Bangalore, India.
> >
> >
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> >
> >
> > ______________________________________________
> > 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<http://www.r-project.org/posting-guide.html>
> > and provide commented, minimal, self-contained, reproducible code.
> >
> >
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> 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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>

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