On Thu, 2007-04-12 at 13:41 -0500, Inman, Brant A. M.D. wrote: > R plotting experts: > > I have a bivariate dataset composed of 300 (x,y) continuous datapoints. > 297 of these points are located within the y range of [0,10], while 2 > are located at 20 and one at 55. No coding errors, real outliers. > > When plotting these data with a scatterplot, I obviously have a problem. > If I plot the full dataset with ylim = c(0,55), then I cannot see the > structure in the data in the [0, 10] range. If I truncate the y axis > with ylim = c(0,10), then I cannot see the 3 outliers. If I break the y > axis from 10 to 20 (using plotrix functions), I still do not see the > data optimally because of the white space from y=20 to y=55. > > What I would like to do is break the y axis at 2 points, roughly 10-20 > and 20-55. Is there a function that can break an axis in 2 places? > > Thanks in advance for any suggestions. > > Brant
Brant, I am not a particular fan of broken axes (though others will disagree), much less two breaks. Presuming that your data might look something like this: http://www.itl.nist.gov/div898/handbook/eda/section3/scattera.htm A couple of thoughts: 1. Not being sure if your data range above actually includes 0, you may want to consider a log scaled axis, if not. 2. I might be tempted to use two plots: A. A first a plot of the entire data set, showing the 3 outliers B. A second plot of the 297 pairs with axes constrained to the appropriate ranges to enable better visualization of the data structure. If number 2 is more appropriate, you could also use par("mfcol") to set up side by side plots. See ?par. HTH, Marc Schwartz ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
