plotConfidenceEllipse function

Add confidence ellipse for groups of points on scatter plot

The method shows confidence ellipse for groups of points on a scatter plot made using mdaplot() function with cgroup parameter. It will work only if cgroup is a factor.

plotConfidenceEllipse(p, conf.level = 0.95, lwd = 1, lty = 1, opacity = 0)

Arguments

• p: plot data returned by function mdaplot().
• conf.level: confidence level to make the ellipse for (between 0 and 1).
• lwd: thickness of line used to show the hull.
• lty: type of line used to show the hull.
• opacity: of opacity is 0 ellipse is transparent otherwise semi-transparent.

Examples

# adds 90% confidence ellipse with semi-transparent area over two clusters of points

library(mdatools)
data(people)
group <- factor(people[, "Sex"], labels = c("Male", "Female"))

# first make plot and then add confidence ellipse
p <- mdaplot(people, type = "p", cgroup = group)
plotConfidenceEllipse(p, conf.level = 0.90, opacity = 0.2)