From: Marc Schwartz (via MN) <mschwartz_at_mn.rr.com>

Date: Fri 02 Dec 2005 - 08:30:58 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Dec 02 08:38:37 2005

Date: Fri 02 Dec 2005 - 08:30:58 EST

On Thu, 2005-12-01 at 23:27 +0300, Evgeniy Kachalin wrote:

*> Marc Schwartz (via MN) пишет:
**> >>Marc Schwartz (via MN) пишет:
**>
*

> >>So plotmeans is incapable of: boxplot(numerical~fact1+fact2). Is there

*> >>any way further?
**> >
**> >
**> > I think that somehow we are talking past each other here.
**> >
**> > plotmeans() does what it is designed to do, which is to simplify the
**> > process of plotting group-wise point estimates and user defined error
**> > bars/intervals around the point estimates.
**> >
**> > In your case, these intervals would be standard deviations around each
**> > of the group means as you have indicated.
**> >
**> > Review the examples in ?plotmeans.
**> >
**> > As Martin and others have pointed out, you need to remove boxplots from
**> > the equation here, as they were not designed to plot means and standard
**> > deviations.
**> >
**>
**> Again, what I'm talking about: plotmeans is incapable of analyzing the
**> formula. For example, I have two factors: A - a, b, c, and B - d, e, f.
**>
**> If i plot: boxplot(num~A+B) what do I get? Eight boxes: ad, ae, af, ba,
**> be, bf, cd, ce, cf. If I plot: plotmeans(num~A+B) - what do I get?
**> Nothing. Because plotmeans cannot combine two factors in various
**> combination. Is there a simple way to do it?
**>
**> Anyway... That's wrong way, all what is neccessary is to have a boxplot
**> with mean istead of median. Is there simple way to do it?
*

If we take SDs out of the picture for the moment, we can do something like this:

# Do the boxplot as you want using the formula boxplot(breaks ~ wool + tension, data = warpbreaks)

# Get the means using tapply() with an interaction of the
# factor levels for each group

means <- with(warpbreaks, tapply(breaks,

list(interaction(wool, tension)), mean, na.rm = TRUE))

# Now add the means to the boxplot, where the # x axis values are 1:number of groups by default points(1:length(means), means, pch = 19)

> Statistical software like Statistica 7.0 offers any possible combination

*> of what "Boxplot" could mean. Is it possible to have only one
**> modification to R's boxplot?
**>
**> Thank you for kind answers.
**> Also please tell me, where should I send replies: to conference adress
**> or to those who answer me directly.
*

Generally best to "reply to all", which gets the message back to the thread participants quickly as well as the list archive for use by others during searches.

**HTH,
**
Marc Schwartz

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Dec 02 08:38:37 2005

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