triplot: 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()andcontour()
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.
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.
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)