| ellipse {mixtools} | R Documentation |
Draw a two-dimensional ellipse that traces a bivariate normal density contour for a given mean vector, covariance matrix, and probability content.
ellipse(mu, sigma, alpha = .05, npoints = 250, newplot = FALSE,
draw = TRUE, ...)
mu |
A 2-vector giving the mean. |
sigma |
A 2x2 matrix giving the covariance matrix. |
alpha |
Probability to be excluded from the ellipse. The default value is alpha = .05, which results in a 95% ellipse. |
npoints |
Number of points comprising the border of the ellipse. |
newplot |
If newplot = TRUE and draw = TRUE, plot the ellipse on a new plot. If newplot = FALSE and draw = TRUE, add the ellipse to an existing plot. |
draw |
If TRUE, draw the ellipse. |
... |
Graphical parameters passed to lines or plot
command. |
ellipse returns an npointsx2 matrix of the points forming the
border of the ellipse.
Johnson, R. A. and Wichern, D. W. (2002) Applied Multivariate Statistical Analysis, Fifth Edition, Prentice Hall.
## Produce a 95% ellipse with the specified mean and covariance structure. mu<-c(1, 3) sigma<-matrix(c(1, .3, .3, 1.5), 2, 2) ellipse(mu, sigma, npoints = 200, newplot = TRUE)