llPlot {dbd} | R Documentation |
Plot the log likelihood surface for the data.
Description
Plot, as a perspective plot or a contour plot, the log likelihood surface for the data set from which parameters are being estimated.
Usage
llPlot(x, distr=c("db","betabinom"),ntop, zeta, size, alim = NULL, blim = NULL,
ngrid = c(100, 100), plotType = c("persp", "contour", "none"),
theta = -30, phi = 40, ...)
Arguments
x |
A vector of numeric data purportedly arising from a db or beta binomial distribution. |
distr |
Character string specifying which of the two relevant distributions (db, or beta binomial) is to be considered. |
ntop |
|
zeta |
|
size |
Integer scalar specifying the upper limit of the “support”
of the beta binomial distribution under consideration. The support
is the set of integers |
alim |
Numeric vector of length 2; the range of |
blim |
Numeric vector of length 2; the range of |
ngrid |
The dimensions of the grid of paramter values at
which the log likelihood is to be evaluated in order to plot
the surface. Note that |
plotType |
Character string specifying the nature of the plot to be
produced. If it is |
theta |
An argument to be passed to |
phi |
An argument to be passed to |
... |
Other arguments that may be passed to |
Details
This function could conceivably be useful in diagnosing problems with parameter estimation should these arise.
Value
A list with entries
x |
The vector of values of the first parameter ( |
y |
The vector of values of the second parameter ( |
z |
An |
dxy |
A data frame with columns named |
fxy |
A numeric vector of length |
There is obviously considerable redundancy in the returned value.
The names x
and y
that are used for the first two
entries of this list conform to the names of the
arguments of persp()
and contour
.
If plotType
is "persp"
or "contour"
the
value is returned invisibly.
Author(s)
Rolf Turner r.turner@auckland.ac.nz
See Also
link{mleDb}()
link{mleBb}()
link{persp}()
link{contour}()
Examples
X <- hmm.discnp::SydColDisc
X$y <- as.numeric(X$y)
X <- split(X,f=with(X,interaction(locn,depth)))
x <- X[[19]]$y
srf <- llPlot(x,ntop=5,zeta=FALSE,alim=c(0.5,0.7),blim=c(0.2,0.4),plotType="c")
## Not run:
if(require(rgl)) {
with(srf,plot3d(ab$alpha,ab$beta,fab)
# Allows dynamic rotation of the surface.
}
## End(Not run)
# Negative (!) parameters for the db distribution.
set.seed(42)
xs <- rdb(100,-1,-1,5)
fit <- mleDb(xs,5)
llPlot(xs,ntop=5,zeta=FALSE,alim=c(-4,2),blim=c(-4,2),plotType="c",
main="log likelihood contours")
points(fit[1],fit[2],pch=20,col="red")
points(-1,-1,pch=20,col="blue")
legend("topright",pch=20,col=c("red","blue"),
legend=c("estimate","true value"),bty="n")