plotly_ellipse: Draw Two-Dimensional Ellipse Based on Mean and Covariance using `plotly`

Description

This is an updated version of ellipse. For more technical details, please refer to ellipse.

Usage

plotly_ellipse(mu, sigma, alpha=.05, npoints=250,
               draw=TRUE, cex = 3, col = "#1f77b4", lwd = 3,
               title = "", title.x = 0.5, title.y = 0.95, title.size = 15,
               xlab = "X", xlab.size = 15, xtick.size = 15,
               ylab = "Y", ylab.size = 15, ytick.size = 15)

Value

plotly_ellipse returns an npointsx2 matrix of the points forming the border of the ellipse.

Arguments

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.
draw: If TRUE, draw the ellipse.
cex: Size of markers.
lwd: Line width of the ellipse.
col: Color of both markers and lines.
title: Text of the main title.
title.size: Size of the main title.
title.x: Horsizontal position of the main title.
title.y: Vertical posotion of the main title.
xlab: Label of X-axis.
xlab.size: Size of the lable of X-axis.
xtick.size: Size of tick lables of X-axis.
ylab: Label of Y-axis.
ylab.size: Size of the lable of Y-axis.
ytick.size: Size of tick lables of Y-axis.

References

Johnson, R. A. and Wichern, D. W. (2002) Applied Multivariate Statistical Analysis, Fifth Edition, Prentice Hall.

Examples

Run this code

## 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)
plotly_ellipse(mu, sigma, npoints = 200)