broman (version 0.38-2)

triplot: Plot Holmans triangle

Description

Plot Holmans triangle (an equilateral triangle used to depict trinomial distributions).

Usage

triplot(labels, ...)

Arguments

labels

Labels for the three corners (lower-right, top, lower-left).

...

Passed to plot.

Value

• None.

Details

Plot of an equilateral triangle, in order to depict trinomial distributions. A trinomial distribution (that is, a trio of non-negative numbers that add to 1) is equated to a point in the triangle through the distances to the three sides. This makes use of the fact that for any point in an equilateral triangle, the sum of the distances to the three sides is constant.

The triplot function creates an empty triangle for use with the related functions tripoints, trilines, triarrow.

References

Holmans P. (1993) Asymptotic properties of affected-sib-pair linkage analysis. Amer J Hum Genet 52, 362--374.

See Also

tripoints, trilines, triarrow

Examples

triplot()

x <- cbind(c(0.9, 0.05, 0.05), c(0.8, 0.1, 0.1), c(0.1, 0.9, 0), c(0, 0.9, 0.1))

tripoints(x, lwd=2, col=c("black","blue","red","green"), pch=16)
trilines(x, lwd=2, col="orange")

y <- cbind(c(0.05, 0.05, 0.9), c(0.25, 0.25, 0.5))
triarrow(y, col="blue", lwd=2, len=0.1)