https://github.com/cran/flexmix
Tip revision: 99591d5078a438ce6dcb5042d265b7a1e1ccc03c authored by Bettina Gruen on 28 May 2009, 00:00:00 UTC
version 2.2-3
version 2.2-3
Tip revision: 99591d5
stepFlexmix.Rd
%
% Copyright (C) 2004-2008 Friedrich Leisch and Bettina Gruen
% $Id: stepFlexmix.Rd 3934 2008-03-26 08:36:26Z gruen $
%
\name{stepFlexmix}
\alias{stepFlexmix}
\alias{stepFlexmix-class}
\alias{plot,stepFlexmix,missing-method}
\alias{show,stepFlexmix-method}
\alias{getModel,stepFlexmix-method}
\alias{unique,stepFlexmix-method}
\title{Run FlexMix Repeatedly}
\description{
Runs flexmix repeatedly for different numbers of components and returns
the maximum likelihood solution for each.
}
\usage{
stepFlexmix(..., k=NULL, nrep=3, verbose=TRUE, drop=TRUE,
unique=FALSE)
\S4method{plot}{stepFlexmix,missing}(x, y, what=c("AIC", "BIC", "ICL"),
xlab=NULL, ylab=NULL, legend="topright", ...)
\S4method{getModel}{stepFlexmix}(object, which="BIC")
\S4method{unique}{stepFlexmix}(x, incomparables = FALSE, ...)
}
\arguments{
\item{\dots}{Passed to \code{\link{flexmix}} (or \code{\link{matplot}}
in the \code{plot} method).}
\item{k}{A vector of integers passed in turn to the \code{k} argument
of \code{\link{flexmix}}.}
\item{nrep}{For each value of \code{k} run \code{\link{flexmix}}
\code{nrep} times and keep only the solution with maximum
likelihood.}
\item{verbose}{If \code{TRUE}, show progress information during
computations.}
\item{drop}{If \code{TRUE} and \code{k} is of length 1, then a single
flexmix object is returned instead of a \code{"stepFlexmix"}
object.}
\item{unique}{If \code{TRUE}, then \code{unique()} is called on the
result, see below.}
\item{x, object}{An object of class \code{"stepFlexmix"}.}
\item{y}{Not used.}
\item{what}{Character vector naming information criteria to
plot. Functions of the same name must exist, which take a
\code{stepFlexmix} object as input and return a numeric vector like
\code{AIC,stepFlexmix-method} (see examples below).}
\item{xlab,ylab}{Graphical parameters.}
\item{legend}{If not \code{FALSE} and \code{what} contains more
than 1 element, a legend is placed at the specified location, see
\code{\link{legend}} for details.}
\item{which}{Number of model to get. If character, interpreted as
number of components or name of an information criterion.}
\item{incomparables}{A vector of values that cannot be compared. Currently,
'FALSE' is the only possible value, meaning that all values
can be compared.}
}
\value{
An object of class \code{"stepFlexmix"} containing the best models
with respect to the log likelihood for the different number of
components in a slot if \code{length(k)>1}, else directly an object of
class \code{"flexmix"}.
If \code{unique=FALSE}, then the resulting object contains one
model per element of \code{k} (which is the numer of clusters the EM
algorithm started with). If \code{unique=TRUE}, then the result
is resorted according to the number of clusters contained in the
fitted models (which may be less than the number with which the EM
algorithm started), and only the maximum likelihood solution for each
number of fitted clusters is kept. This operation can also be done
manually by calling \code{unique()} on objects of class
\code{"stepFlexmix"}.
}
\author{Friedrich Leisch and Bettina Gruen}
\references{
Friedrich Leisch. FlexMix: A general framework for finite mixture
models and latent class regression kin R. Journal of Statistical
Software, 11(8), 2004. http://www.jstatsoft.org/v11/i08/
}
\examples{
data("Nclus")
set.seed(511)
## try 5 times for k=4
ex1 <- stepFlexmix(Nclus~1, k=4, model=FLXMCmvnorm(diag=FALSE), nrep=5)
ex1
## now 3 times each for k=2:6, specify control parameter
ex2 <- stepFlexmix(Nclus~1, k=2:6, model=FLXMCmvnorm(diag=FALSE),
control=list(minprior=0), nrep=3)
ex2
plot(ex2)
## get BIC values
BIC(ex2)
## get smallest model
getModel(ex2, which=1)
## get model with 3 components
getModel(ex2, which="3")
## get model with smallest ICL (here same as for AIC and BIC: true k=4)
getModel(ex2, which="ICL")
## now 1 time each for k=2:6, with larger minimum prior
ex3 <- stepFlexmix(Nclus~1, k=2:6, model=FLXMCmvnorm(diag=FALSE),
control=list(minprior=0.1), nrep=1)
ex3
## keep only maximum likelihood solution for each unique number of
## fitted clusters:
unique(ex3)
}
\keyword{cluster}
\keyword{regression}