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basic boxplot questions

4 messages · ivo welch, K. Elo, PIKAL Petr

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dear R experts:

I am playing with boxplots for the first time.  most of it is
intuitive, although there was less info on the web than I had hoped.

alas, for some odd reason, my R boxplots have some fat black dots, not
just the hollow outlier plots.  Is there a description of when R draws
hollow vs. fat dots somewhere?

[and what is the parameter to change just the size of these dots?]

Also, let me show my fundamental ignorance:  I am a little surprised
that the average box boxplot would not show the mean and sdv, too, at
least optionally.  Is there a common way to accomplish this (e.g., in
a different color), or do I just construct it myself with standard R
graphics line() commands?

advice appreciated.

regards,

/iaw
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ivo welch kirjoitti:
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Hi Ivo,
ivo welch wrote:
Have you tried the command '?boxplot' already? It should help you to
understand the syntax.
Could you post the command(s) you have entered? Without a reproducible
example we are tapping in the dark.

Kind regards,
Kimmo
#
Hi

r-help-bounces at r-project.org napsal dne 16.01.2009 15:24:26:
Standard use of boxplot does not draw filled dots, just hollow points. 
Didnt you by chance use pch=19.
Details on bxp help page

outlty, outlwd, outpch, outcex, outcol, outbg: 
outlier line type, line width, point character, point size expansion, 
color, and background color. The default outlty= "blank" suppresses the 
lines and outpch=NA suppresses points.
I always expect boxplot to show median and IQR, however I have seen such 
twisted boxplots elsewhere. Eg if you looked in CRAN search facility you 
would easily find

R-help archive January 2004: Re: [R] adding mean to boxplot

Regards
Petr
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