ternaryplot {Zelig} | R Documentation

## Ternary diagram

### Description

Visualizes compositional, 3-dimensional data in an equilateral triangle (from the vcd library, Version 0.1-3.3, Date 2004-04-21), using plot graphics. Differs from implementation in vcd (0.9-7), which uses grid graphics.

### Usage

    ternaryplot(x, scale = 1, dimnames = NULL, dimnames.position = c("corner","edge","none"),
                dimnames.color = "black", id = NULL, id.color = "black", coordinates = FALSE,
                grid = TRUE, grid.color = "gray", labels = c("inside", "outside", "none"),
                labels.color = "darkgray", border = "black", bg = "white", pch = 19, cex = 1,
                prop.size = FALSE, col = "red", main = "ternary plot", ...)

### 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.
`id` | optional labels to be plotted below the plot symbols. `coordinates` and `id` are mutual exclusive.
`id.color` | color 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.
`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.
`...` | 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
david.meyer@ci.tuwien.ac.at

### References

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

### See Also

`ternarypoints`

### Examples

    data(mexico)
    if (require(VGAM)) {
    z.out <- zelig(as.factor(vote88) ~ pristr + othcok + othsocok,
                    model = "mlogit", data = mexico)
    x.out <- setx(z.out)
    s.out <- sim(z.out, x = x.out)

    ternaryplot(s.out$qi$ev, pch = ".", col = "blue",
                main = "1988 Mexican Presidential Election")
    }

[Package Zelig version 3.4-3 Index]