It's already there in EDA! Se pp 39-47. -- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA "The business of the statistician is to catalyze the scientific learning process." - George E. P. Box
> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Michael H. Prager > Sent: Thursday, December 01, 2005 10:11 AM > To: [email protected] > Subject: Re: [R] Impaired boxplot functionality - mean > instead of median > > All-- > > Would someone kindly post the reference to Tukey's formula > for a boxplot > without whiskers? > > I am looking at his book "Exploratory Data Analysis" from 1977. The > index includes "box-and-whisker" plot but not "boxplot." On > page 39-40 > construction of the plot is described, including the statements: "We > draw a long, thinnish box that stretches from hinge to hinge, > crossing > it with a bar at the median. Then we draw a 'whisker' from > each end of > the box to the corresponding extreme." > > MHP > > > on 12/1/2005 11:57 AM P Ehlers said the following: > > >I'd like to add two comments to Martin's sensible response. > > > >1. I've seen several intro-stats textbooks that define a > >boxplot to have whiskers to the extreme data values > >and then define Tukey's boxplot as a "modified" boxplot. > >I wish authors wouldn't do that. > > > >2. I've also seen boxplots used for sample sizes as small > >as -- are you ready for it? -- n = 2!! (Admittedly, only in > >plots comparing several groups.) The help page for > >stripchart() points out that stripcharts "are a good > >alternative to boxplots when sample sizes are small". > >My own rule-of-thumb: n > 20 for single boxplots, n > 12 > >for multiple boxplots. > > > >Peter Ehlers > > > >Martin Maechler wrote: > > > > > > > >>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! > >> > >>Martin Maechler, ETH Zurich > >> > >> > >> > >> > >>>>>>>"Evgeniy" == Evgeniy Kachalin <[EMAIL PROTECTED]> > >>>>>>> on Thu, 01 Dec 2005 19:04:47 +0300 writes: > >>>>>>> > >>>>>>> > >> Evgeniy> Hello to all users and wizards. > >> Evgeniy> I am regulary using 'boxplot' function or its > analogue - 'bwplot' from > >> Evgeniy> the 'lattice' library. > >> > >> [there's the lattice *package* !] > >> > >> Evgeniy> But they are, as far as I understand, totally > >> Evgeniy> flawed in functionality: they miss ability to > select what they would > >> Evgeniy> draw 'in the middle' - median, mean. What the > box means - standard > >> Evgeniy> error, 90% or something else. What the > whiskers mean - 100%, 99% or > >> Evgeniy> something else. > >> Evgeniy> Is there any way to realize it? Or is there > any other good data > >> Evgeniy> visualization function for comparing means of > various data groups? > >> Evgeniy> Ideally I would like to have a bit more > customised function for doing > >> Evgeniy> that. For example, 'boxplot(a~b,data=d,mid='mean'). > >> > >> > >> Evgeniy> -- > >> Evgeniy> Evgeniy, ICQ 38317310. > >> > >>______________________________________________ > >>[email protected] mailing list > >>https://stat.ethz.ch/mailman/listinfo/r-help > >>PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > >> > >> > > > >______________________________________________ > >[email protected] mailing list > >https://stat.ethz.ch/mailman/listinfo/r-help > >PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > > > > > -- > > Michael Prager, Ph.D. > Population Dynamics Team, NMFS SE Fisheries Science Center > NOAA Center for Coastal Fisheries and Habitat Research > Beaufort, North Carolina 28516 > http://shrimp.ccfhrb.noaa.gov/~mprager/ > Opinions expressed are personal, not official. No > government endorsement of any product is made or implied. > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
