ellipse {ellipse}R Documentation

Make an ellipse

Description

This function returns an ellipse or other outline of a confidence region for two parameters. This is a generic function. Functions with names beginning in ellipse. will be methods for this function. lm, nls, profile, profile.nls

Usage

ellipse(x, ...)

Arguments

x An S object.
... Each of the specialized types uses different optional parameters.

Value

A matrix is returned with two columns outlining an ellipse or a confidence region.

See Also

ellipse.arima, plotcorr

Examples

# Plot an ellipse corresponding to a 95% probability region for a
# bivariate normal distribution with mean 0, unit variances and 
# correlation 0.8.
plot(ellipse(0.8),type='l')
# Plot the joint 95% confidence region for the weight and displacement
# parameters in the Fuel dataset
data(fuel.frame)
fit <- lm(Fuel ~ . , fuel.frame)
plot(ellipse(fit,which=c('Weight','Disp.')),type='l')