[R] Boxplot: quartiles/outliers

[Greg Snow]

For your outlier question, look at the 'range' argument to the boxplot
function.  It defaults to 1.5 meaning that any points more than 1.5*IQR
from the 1st and 3rd quartiles are considered outliers.  If you make
this smaller, you will potentially see more outliers, if you make it
larger then it will show fewer outliers.  The special case of 0 means
that you don't want any points to be shown as outliers and the wiskers
will go all the way to the min and max points.

Hope this helps,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at intermountainmail.org
(801) 408-8111
 
 

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Cecilia Alm
> Sent: Sunday, February 11, 2007 9:05 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] Boxplot: quartiles/outliers
> 
> For boxplot(),  is it possible to pass in a parameter to 
> change the default way that the 1st and 3rd quartiles are 
> computed? (specifically, I'd like to use type 6 described in 
> the quantile function).
> 
> Also, what are the options for how outliers are computed, and 
> how can one change them?
> 
> Thank you
> 
> 	[[alternative HTML version deleted]]
> 
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