triplot: Plot Holmans triangle

In broman: Karl Broman's R Code

Plot Holmans triangle

Description

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

Usage

triplot(
  labels = c("(1,0,0)", "(0,1,0)", "(0,0,1)"),
  col = "black",
  lwd = 2,
  bgcolor = "gray90",
  gridlines = 0,
  grid_col = "white",
  grid_lty = 1,
  grid_lwd = 1,
  ...
)

Arguments

labels	Labels for the three corners (lower-right, top, lower-left).
col	Color of edges of triangle
lwd	Line width for edges of triangle
bgcolor	Background color for triangle
gridlines	Number of grid lines (if 0, no grid lines will be plotted)
grid_col	Color of grid lines
grid_lty	Line type of grid lines
grid_lwd	Line width of grid lines
...	Passed to plot().

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().

Value

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

See Also

tripoints(), 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)

broman documentation built on May 29, 2024, 7:18 a.m.