tripoints {broman}

Plot points within a Holmans triangle

Description

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

Usage

tripoints(x, ...)

Arguments

x

A matrix with three rows, each column being a trinomial distribution.

...

Passed to graphics::points().

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. First use triplot() to first plot the equilateral triangle.

Value

The (x,y) coordinates of the points plotted.

See Also

triplot(), trilines(), triarrow(), tritext()

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)