[R] Median line with stripchart

[David L Carlson]

This automates things a bit once we re-organize your data.

my.newdata <- stack(data.frame(my.data), select=c(Control, Case))
stripchart(values~ind, my.newdata, method = "stack", offset=1/3,
    vertical = TRUE, pch=19)
medians <- tapply(my.newdata$values, my.newdata$ind, median)
points(c(1, 2), medians, pch="-", cex=3, col="red")

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352

> -----Original Message-----
> From: Luigi [mailto:marongiu.luigi at gmail.com]
> Sent: Wednesday, June 13, 2012 6:44 PM
> To: dcarlson at tamu.edu
> Cc: r-help at r-project.org
> Subject: RE: [R] Median line with stripchart
> 
> Sorry for the inconvenience,
> I have added an EXAMPLE. Here I am plotting few data with the relative
> median values. The median are added ad hoc using the points() function,
> which is not really professional and is time consuming. With boxplot()
> the
> median values are automatically drawn, with striplot() this is not true
> and
> I couldn't find another suitable package.
> Note: usually I work with data frames and the group names is plotted
> correctly; here I have added the group names with text().
> 
> Thank you,
> Regards,
> Luigi
> 
> ########### THE EXAMPLE
> #######################################################################
> #####
> #############
> # assigning data
> Control<-c(0.002325138,	0.002460417, 0.010971385, 0.033016026,
> 0.035646472,
> 3.161701212, 5.10096383, 5.327863403)
> Case<-c(0.000142311, 0.010751273, 0.151395382, 0.153094117,
> 0.381564497,
> 1.32567787, 2.915908912, 14.2888441)
> my.data<-cbind(Control, Case)
> Med.Control<-0.034331249
> Med.Case<-0.267329307
> 
> 
> # plotting data
> stripchart(Control, method = "stack" , offset=1/3, vertical = TRUE,
> pch=19,
> at=0.5)
> stripchart(Case, method = "stack" , offset=1/3, vertical = TRUE,
> pch=19,
> at=1.5,add=TRUE)
> 
> # adding text
> text(0.7, 0, labels = "Controls")
> text(1.7, 0, labels = "Cases")
> 
> # adding median values
> points(0.5, Med.Control, pch="-", cex=3, col="red")
> points(1.5, Med.Case, pch="-", cex=3, col="red")
> 
> #######################################################################
> #####
> #####################################
> 
> 
> -----Original Message-----
> From: David L Carlson [mailto:dcarlson at tamu.edu]
> Sent: 13 June 2012 17:29
> To: 'Luigi'; r-help at r-project.org
> Subject: RE: [R] Median line with stripchart
> 
> It would help if you would give us a copy of at least part of the data
> you
> are using and show us what you have tried so far. This is a simple
> example.
> In this case the median is for the entire data set not for a single
> group.
> But you really didn't give us enough information.
> 
> x <- rnorm(75)
> g <- rep(1:3, 25)
> stripchart(x~g)
> abline(v=median(x), lty=2)
> 
> ----------------------------------------------
> David L Carlson
> Associate Professor of Anthropology
> Texas A&M University
> College Station, TX 77843-4352
> 
> 
> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> > project.org] On Behalf Of Luigi
> > Sent: Wednesday, June 13, 2012 10:57 AM
> > To: r-help at r-project.org
> > Subject: [R] Median line with stripchart
> >
> > Dear all,
> >
> > I would like to ask if it possible to draw a median line in a
> > Stripchart,
> > either using the built-in STRIPCHART function or with another
> package.
> >
> > I was expecting stripchart() to work more or less like boxplot(), but
> I
> > couldn't find an easy way to draw a mean or median line, neither I
> > found
> > this option in other packages.
> >
> > Could somebody help?
> >
> > Best regards,
> >
> >
> >
> > Luigi Marongiu, MSc
> >
> >
> >
> >
> > 	[[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-
> > guide.html
> > and provide commented, minimal, self-contained, reproducible code.