Hi:

Point well taken, Robert. This is a good example of the difference between
how
something is defined mathematically as opposed to how it is applied
computationally.
Thank you for the clarification.

Regards,
Dennis

On Wed, May 12, 2010 at 9:51 AM, Robert Baer <rbaer@atsu.edu> wrote:

>
> ----- Original Message ----- Fantastic!
>
>
> It would be great if the description could be modified to include the
> mysterious bit about the upper and lower bound whisker positions:
>
> upper whisker = min(max(x), Q_3 + 1.5 * IQR)
> lower whisker = max(min(x), Q_1 - 1.5 * IQR)
>
> -- snip --
> ----------------------
> NOT quite!
>
> The boxplot.stats help reads under the coef argument:
> "... the whiskers extend to the most extreme data point which is no more
> than coef times the length of the box away from the box."
>
>
> If there are outliers, and the most extreme data point within 1.5 *IQR of
> Q1 or Q3 is less than 1.5 IQRs, and the wisker may "end earlier" than
> 1.5*IQR, but the data point at which it ends may NOT be max(x) or min(x).
>

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