ternaryplot: Ternary Diagram

In vcd: Visualizing Categorical Data

Ternary Diagram

Description

Visualizes compositional, 3-dimensional data in an equilateral triangle.

Usage

ternaryplot(x, scale = 1, dimnames = NULL,
  dimnames_position = c("corner","edge","none"),
  dimnames_color = "black", dimnames_rot = c(-60, 60, 0),
  id = NULL, id_color = "black",
  id_just = c("center", "center"),
  coordinates = FALSE, grid = TRUE, grid_color = "gray",
  labels = c("inside", "outside", "none"),
  labels_color = "darkgray", labels_rot = c(120, -120, 0),
  border = "black", bg = "white",
  pch = 19, cex = 1, prop_size = FALSE, col = "red",
  main = "ternary plot", newpage = TRUE, pop = TRUE,
  return_grob = FALSE, ...)

Arguments

x	a matrix with three columns.
scale	row sums scale to be used.
dimnames	dimension labels (defaults to the column names of x).
dimnames_position, dimnames_color	position and color of dimension labels.
dimnames_rot	Numeric vector of length 3, specifying the angle of the dimension labels.
id	optional labels to be plotted below the plot symbols. coordinates and id are mutual exclusive.
id_color	color of these labels.
id_just	character vector of length 1 or 2 indicating the justification of these labels.
coordinates	if TRUE, the coordinates of the points are plotted below them. coordinates and id are mutual exclusive.
grid	if TRUE, a grid is plotted. May optionally be a string indicating the line type (default: "dotted").
grid_color	grid color.
labels, labels_color	position and color of the grid labels.
labels_rot	Numeric vector of length 3, specifying the angle of the grid labels.
border	color of the triangle border.
bg	triangle background.
pch	plotting character. Defaults to filled dots.
cex	a numerical value giving the amount by which plotting text and symbols should be scaled relative to the default. Ignored for the symbol size if prop_size is not FALSE.
prop_size	if TRUE, the symbol size is plotted proportional to the row sum of the three variables, i.e., represents the weight of the observation.
col	plotting color.
main	main title.
newpage	if TRUE, the plot will appear on a new graphics page.
pop	logical; if TRUE, all newly generated viewports are popped after plotting.
return_grob	logical. Should a snapshot of the display be returned as a grid grob?
...	additional graphics parameters (see par)

Details

A points' coordinates are found by computing the gravity center of mass points using the data entries as weights. Thus, the coordinates of a point P(a,b,c), a + b + c = 1, are: P(b + c/2, c \sqrt{3}/2).

Author(s)

David Meyer [e-mail]

References

M. Friendly (2000), Visualizing Categorical Data. SAS Institute, Cary, NC.

Examples

data("Arthritis")

## Build table by crossing Treatment and Sex
tab <- as.table(xtabs(~ I(Sex:Treatment) + Improved, data = Arthritis))

## Mark groups
col <- c("red", "red", "blue", "blue")
pch <- c(1, 19, 1, 19)

## plot
ternaryplot(
            tab,
            col = col,
            pch = pch,
            prop_size = TRUE,
            bg = "lightgray",
            grid_color = "white",
            labels_color = "white",
            main = "Arthritis Treatment Data"
           )
## legend
grid_legend(0.8, 0.7, pch, col, rownames(tab), title = "GROUP")

## Titanic
data("Lifeboats")
attach(Lifeboats)
ternaryplot(
  Lifeboats[,4:6],
  pch = ifelse(side == "Port", 1, 19),
  col = ifelse(side == "Port", "red", "blue"),
  id  = ifelse(men / total > 0.1, as.character(boat), NA),
  prop_size = 2,
  dimnames_position = "edge",
  main = "Lifeboats on Titanic"
)
grid_legend(0.8, 0.9, c(1, 19),
  c("red", "blue"), c("Port", "Starboard"),
  title = "SIDE")


## Hitters
data("Hitters")
attach(Hitters)
colors <- c("black","red","green","blue","red","black","blue")
pch <- substr(levels(Positions), 1, 1)
ternaryplot(
  Hitters[,2:4],
  pch = as.character(Positions),
  col = colors[as.numeric(Positions)],
  main = "Baseball Hitters Data"
)
grid_legend(0.8, 0.9, pch, colors, levels(Positions),
  title = "POSITION(S)")

vcd documentation built on Sept. 17, 2024, 1:08 a.m.