On 4/12/07, Marc Schwartz <[EMAIL PROTECTED]> wrote: > 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 >
I was thinking plot the data without the outliers and include a smaller inscribed plot in a corner showing all the data (the "global view"). But I couldn't figure out how to do this. (I think legend() works very hard to do this type of thing.) Stephen ______________________________________________ [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.
