[Rd] plot.lm mislabels points with na.exclude (PR#3750)

richard_raubertas at merck.com richard_raubertas at merck.com
Fri Aug 15 01:38:29 MEST 2003


R 1.7.1 on Windows XP

The "normal Q-Q plot" produced by plot.lm() mislabels points 
when the model is fitted using na.action=na.exclude.  Example:

x <- 1:50
y <- x + rnorm(50)
y[c(5,10,15)] <- NA   # insert some NA's
y[40] <- 50  # add an outlier
plot(lm(y ~ x, na.action=na.omit))  # outlier correctly labeled in all 
                                    # four plots
plot(lm(y ~ x, na.action=na.exclude)) # labels attached to wrong points
                                      # in the QQ plot (only)


Rich Raubertas
Biometrics Research
Merck & Co.

------------------------------------------------------------------------------
Notice:  This e-mail message, together with any attachments, contains
information of Merck & Co., Inc. (Whitehouse Station, New Jersey, USA), and/or
its affiliates (which may be known outside the United States as Merck Frosst,
Merck Sharp & Dohme or MSD) that may be confidential, proprietary copyrighted
and/or legally privileged, and is intended solely for the use of the
individual or entity named on this message.  If you are not the intended
recipient, and have received this message in error, please immediately return
this by e-mail and then delete it.



More information about the R-devel mailing list