Message-ID: <083A0C62-5967-4F02-9DBE-9812ED684AA8@comcast.net>
Date: 2009-03-17T16:38:20Z
From: David Winsemius
Subject: qqline plots outside plot area
I just executed the example in the R graph gallery for qqplot and it
includes a call to qqline. It plots the line beyond the plotting
region, unlike the illustration and unlike the behavior of any of the
other "line" functions in my (limited) experience. the example on the
help page for qqplot/qqline does the same. It does not appear that I
have masked qqline with another package version.
y <- rt(200, df = 5)
qqnorm(y); qqline(y, col = 2)
--
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
> sessionInfo()
R version 2.8.1 Patched (2009-01-19 r47650)
i386-apple-darwin9.6.0
locale:
en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8
attached base packages:
[1] splines stats graphics grDevices utils datasets
methods base
other attached packages:
[1] caret_4.08 UsingR_0.1-12 codetools_0.2-1 lattice_0.17-20
Design_2.1-2 Hmisc_3.5-2 survival_2.34-1
loaded via a namespace (and not attached):
[1] cluster_1.11.12 grid_2.8.1 tools_2.8.1
> qqline
function (y, datax = FALSE, ...)
{
y <- quantile(y[!is.na(y)], c(0.25, 0.75))
x <- qnorm(c(0.25, 0.75))
if (datax) {
slope <- diff(x)/diff(y)
int <- x[1] - slope * y[1]
}
else {
slope <- diff(y)/diff(x)
int <- y[1] - slope * x[1]
}
abline(int, slope, ...)
}
<environment: namespace:stats>
>