Hi:
Try this:
First put your data into a data frame (it's not necessary, but it's
easier)
ol <- data.frame(grp = grp, size = size)
boxplot(size ~ grp, data = ol, style = 'att', medpch = "o",
ylab = "Prostate Volume (cm3)")
mns <- with(ol, tapply(size, grp, mean))
points(1:5, mns, pch = '+')
HTH,
Dennis
On Wed, Jan 6, 2010 at 1:36 PM, oscar linares <winsaam@gmail.com> wrote:
> Dear Rexperts,
>
> I am trying to add a '+' identifying the mean in a boxplot using
the
> following
> sizelist <- split(size, grp)
> centers <- boxplot(sizelist, style.bxp = "att", medpch =
"o",
> ylab = "Prostate Volume (cm3)")
> points(centers, unlist(lapply(sizelist, mean)), pch = "+")
> But, I get error
> Error in xy.coords(x, y) : 'x' and 'y' lengths differ
> which I do not understand.
> The data follows
> grp size
> AE 9.132
> AE 10.07
> AE 20.077
> AE 14.691
> AE 23.698
> E1 10.356
> E1 6.313
> E1 21.708
> E1 12.651
> E1 15.464
> E2 37.2
> E2 12.639
> E2 16.791
> E2 36.996
> E2 22.808
> CC 1.975
> CC 3.125
> CC 4.433
> CC 6.154
> CC 4.175
> NC 9.301
> NC 13.531
> NC 12.84
> NC 14.336
> NC 25.102
>
> Please help.
>
> --
> Oscar
> Oscar A. Linares, MD
> Translational Medicine Unit
> LaPlaisance Bay, Bolles Harbor
> Monroe, Michigan 48161
>
> Department of Medicine,
> University of Toledo College of Medicine
> Toledo, OH 43606-3390
>
> Department of Internal Medicine,
> The Detroit Medical Center (DMC)
> Harper University Hospital
> Wayne State University School of Medicine
> Detroit, Michigan 48201
>
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>
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> and provide commented, minimal, self-contained, reproducible code.
>
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