Usage
ellipse(center, shape, radius, log="", center.pch=19, center.cex=1.5,
segments=51, draw=TRUE, add=draw, xlab="", ylab="",
col=palette()[2], lwd=2, fill=FALSE, fill.alpha=0.3, grid=TRUE, ...)
dataEllipse(x, y, weights, log="", levels=c(0.5, 0.95), center.pch=19, center.cex=1.5,
draw=TRUE, plot.points=draw, add=!plot.points, segments=51, robust=FALSE,
xlab=deparse(substitute(x)),
ylab=deparse(substitute(y)),
col=palette()[1:2], lwd=2, fill=FALSE, fill.alpha=0.3, grid=TRUE, ...)
confidenceEllipse(model, ...)
## S3 method for class 'lm':
confidenceEllipse(model, which.coef, L, levels=0.95, Scheffe=FALSE, dfn,
center.pch=19, center.cex=1.5, segments=51, xlab, ylab,
col=palette()[2], lwd=2, fill=FALSE, fill.alpha=0.3, draw=TRUE, add=!draw, ...)
## S3 method for class 'glm':
confidenceEllipse(model, chisq, ...)
## S3 method for class 'default':
confidenceEllipse(model, which.coef, L, levels=0.95, Scheffe=FALSE, dfn,
center.pch=19, center.cex=1.5, segments=51, xlab, ylab,
col=palette()[2], lwd=2, fill=FALSE, fill.alpha=0.3, draw=TRUE, add=!draw, ...)
Arguments
center
2-element vector with coordinates of center of ellipse.
shape
$2\times 2$ shape (or covariance) matrix.
radius
radius of circle generating the ellipse.
log
when an ellipse is to be added to an existing plot, indicates
whether computations were on logged values and to be plotted on logged
axes; "x" if the x-axis is logged, "y" if the y-axis is
logged, and "xy"
center.pch
character for plotting ellipse center; if FALSE or NULL the center point isn't plotted.
center.cex
relative size of character for plotting ellipse center.
segments
number of line-segments used to draw ellipse.
draw
if TRUE produce graphical output; if FALSE, only invisibly return coordinates of ellipse(s).
add
if TRUE add ellipse(s) to current plot.
xlab
label for horizontal axis.
ylab
label for vertical axis.
x
a numeric vector, or (if y is missing) a 2-column numeric matrix.
y
a numeric vector, of the same length as x.
weights
a numeric vector of weights, of the same length as x and y to be used by cov.wt
or cov.trob in computing a weighted plot.points
if FALSE data ellipses are drawn,
but points are not plotted.
levels
draw elliptical contours at these (normal) probability or confidence levels.
robust
if TRUE use the cov.trob function in the MASS package
to calculate the center and covariance matrix for the data ellipse. model
a model object produced by lm or glm.
which.coef
2-element vector giving indices of coefficients to plot;
if missing, the first two coefficients (disregarding the regression constant)
will be selected.
L
As an alternative to selecting coefficients to plot, a transformation matrix can be specified to compute two
linear combinations of the coefficients; if the L matrix is given, it takes precedence over the which.coef
arg
Scheffe
if TRUE scale the ellipse so that its projections onto the
axes give Scheffe confidence intervals for the coefficients.
dfn
``numerator'' degrees of freedom (or just degrees of freedom for a GLM) for
drawing the confidence ellipse. Defaults to the number of coefficients in the model (disregarding the constant) if
Scheffe is TRUE, or to
chisq
if TRUE, the confidence ellipse for the coefficients in a generalized linear model are
based on the chisquare statistic, if FALSE on the $F$-statistic. This corresponds to using the default
and linear-model methods resp
col
color for lines and ellipse center; the default is the second entry
in the current color palette (see palette
and par). For < lwd
line width; default is 2 (see par). fill
fill the ellipse with translucent color col (default, FALSE)?
fill.alpha
transparency of fill (default = 0.3).
...
other plotting parameters to be passed to plot and
line.
grid
If TRUE, the default, a light-gray background grid is put on the
graph