[R] Impaired boxplot functionality - mean instead of median

Evgeniy Kachalin ka4alin at yandex.ru
Thu Dec 1 17:40:14 CET 2005


Martin Maechler ЃпЃиЃшЃеЃт:
> Boxplots were invented by John W. Tukey and I think should be
> counted among the top "small but smart" achievements from the
> 20th century.  Very wisely he did *not* use mean and standard deviations.
> 
> Even though it's possible to draw boxplots that are not boxplots
> (and people only recently explained how to do this with R on this
>  mailing list), I'm arguing very strongly against this.
> 
> If I see a boxplot - I'd want it to be a boxplot and not have
> the silly (please excuse)  10%--------90% whiskers  which
> declare 20% of the points as outliers {in the boxplot sense}.
> 
> If you want the mean +/- sd plot, do *not* misuse boxplots
> for them, please! 
> 

So I analize genetics data. I have some factor (gene variant, c(1,2,3))
and the quantitative variable corresponding to that factor. How do I
visualize this situation? Compare mean of samples corresponding to
factor values?

Should boxplot support 'mean-in-the-middle', it would fit my needs
ideally. How do I plot mean +/- SD plot?

Also there is a way to rewrite boxplot.stats and replace "fivenum" there
for self-made function. Then I would need to write self-made
boxplot.formula (or boxplot.default?) function. And all this stuff would
not be configurable. I'm still novice in R, so I need simple way to
pre-visualize my data and estimate approximate result.



-- 
Evgeniy, ICQ 38317310.




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