\name{buildHyperDirichletDist}
\alias{buildHyperDirichletDist}
\title{Builds a hyper-Dirichlet distributon from a parameter table}
\description{
  This takes a data frame in which the factor columns represent 
  the condition (parent) variables and the numeric columns represent
  states of the child variables and builds a hyper-Dirichlet
  distribution object.
}
\usage{
buildHyperDirichletDist(depVarName, parameterTable)
}
\arguments{
  \item{depVarName}{A character vector of length one giving the
    dependent variable.}
  \item{parameterTable}{A data frame containing hyper-Dirichlet
    parameters (see Details).} 
}
\details{
  The \code{parameterTable} argument is a data frame in which each row
  represents the parameters of an independent Dirichlet distribution.
  Columns in the data frame which are factors are assumed
  to hold values for the parent (conditioning) variables.  Columns in
  the data frame which are numeric are assumed to correspond to possible
  states of the child (dependent) variable.

  Most of the appropriate meta-data for the distribution object --- the
  names of the parent variables and the states of the child variable ---
  can be derivied from the parameter table.  The remaining piece of
  information is the name of the dependent variable, which is given in
  \code{depVarName}.  

}
\value{
  An object of class \code{\link{distribution}} of type
  \dQuote{Hyperdirichlet Distribuiton} using \code{parameterTable} as
  its parameter table. 
}
\author{Russell Almond}
\section{Under Construction}{
  StatShop supports an alternative format for the parameter table
  involving an extra \sQuote{Sum} and \sQuote{Scale} column (see
  \code{\link{scaleTable}}).  This is not yet supported.
}
\seealso{\code{\link{getTableParents}}, \code{\link{distribution}},
  \code{\link{scaleTable}}
}
\examples{
#conditional table
X2.ptf <- data.frame(Theta=c("Expert","Novice"),
                     correct=c(4,2),
                     incorrect=c(2,4))

#Unconditional table
Theta.ptf <- data.frame(Expert=3,Novice=3)

Theta.dist <- buildHyperDirichletDist("Theta",Theta.ptf)
X2.dist <- buildHyperDirichletDist("X2",rescaleTable(X2.ptf,100))

}
\keyword{manip}