triplot {hyperdirichlet} | R Documentation

## Plot density of a 3D hyperdirichlet distribution

### Description

Plot (log) density of a 3D hyperdirichlet distribution

### Usage

    triplot(HD, l = 100, do_image=TRUE, do_contour=TRUE, discard = 0.05, ...)

### Arguments

`HD` | Either a function of a three-element vector, or a hyperdirichlet object
`l` | Size of plot; larger values look much better but take longer
`do_image,do_contour` | Boolean, indicating whether to plot the image and contour respectively
`discard` | Numeric; default 0.05 means to disregard densities less than the fifth percentile (i.e. quantile 0.05). This makes the contour plot intervals prettier
`...` | Further arguments passed to `image()` and `contour()`

### Details

If argument `HD` is not a function it is interpreted as a hyperdirichlet object. If `HD` is a function, `triplot()` will pass it a three-element vector.

If argument `HD` is a hyperdirichlet object, then `triplot()` plots contours of the log of the density (ie support). If you want likelihood instead, see examples section for how to do this.

### Value

The function returns (invisibly) an `l`-by-`l` matrix holding the support as a function of the two independent variables, with `NA` outside the domain.

### Author(s)

Robin K. S. Hankin

### Examples

    a <- dirichlet(1:3)
    triplot(a,l=20)

    f <- function(p){1-p[1]+p[2]+8*p[2]^2*p[3]}
    triplot(f)

    g <- function(p){dhyperdirichlet(p, a, log=FALSE)}
    triplot(g,l=20)

[Package hyperdirichlet version 1.3-8 Index]