xyellipse
DESCRIPTION:
Scatter Plot with Overlaid Ellipse(s)
USAGE:
xyellipse(x, variables=c(1, 2), plot.data=T, confidence=0.95)
REQUIRED ARGUMENTS:
- x
-
a
cov
,
covRob
, or
fit.models
(containing only
cov
and
covRob
elements) object.
OPTIONAL ARGUMENTS:
- variables
-
when the dimension of the covarianvce matrix is greater than 2 this argument
is used to specify which pair of variables to plot.
It can be either a character vector containing two names
or a numeric vector containing two column indicies.
- plot.data
-
a logical flag, if TRUE a scatter plot of the data is added to the plot.
- confidence
-
the fraction of the density inside the ellipse.
SIDE EFFECTS:
A plot is produced on a graphics device.
EXAMPLES:
stack.fm <- fit.models(list(Robust="covRob", Classical="cov"),
data=stack.dat)
xyellipse(stack.fm, variables = c("Air.Flow", "Acid.Conc."))