Dear Felipe,
Assuming you are not interested in the exact formulae that are used to
calculate each of these, from top to bottom it is:
minimum, lower quartile, median, upper quartile, maximum
If there are dots, these usually indicate outliers.
Please read ?boxplot for more details on what R will do when. If you
are interested in the specifics of the computations, read
?boxplot.stats
Hope that helps,
Josh
See inline comments to match these things to your terms.
On Tue, Sep 28, 2010 at 10:06 PM, Luis Felipe Parra
<felipe.parra at quantil.com.co> wrote:>
> Hello, does somebody know in a boxplot, what does each element in the
> boxplot represent?
>
> 1. lines at the extremes of the dotted lines?
min and max (unless there are outliers AND you have not set range = 0)
> 2. Extremes of the boxes
lower & upper quartile
> 3. Black line in the middle of the box?
median
> 4. notches?
>
> Thank you
>
> Felipe Parra
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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--
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/