\HeaderA{tmixture}{Estimate Scale Factor in Mixture of t-Distributions}{tmixture}
\methaliasA{tmixture.matrix}{tmixture}{tmixture.matrix}
\methaliasA{tmixture.vector}{tmixture}{tmixture.vector}
\keyword{htest}{tmixture}
\begin{Description}\relax
This function estimates the unscaled standard deviation of the log fold change for differentially expressed genes.
It is called by the function \code{ebayes} and is not intended to be called by users.
\end{Description}
\begin{Usage}
\begin{verbatim}
tmixture.vector(tstat,stdev.unscaled,df,proportion,v0.lim=NULL)
tmixture.matrix(tstat,stdev.unscaled,df,proportion,v0.lim=NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{tstat}] numeric vector or matrix of t-statistics
\item[\code{stdev.unscaled}] numeric matrix conformal with \code{tstatf} containing the unscaled standard deviations for the coefficient estimators
\item[\code{df}] numeric vector giving the degrees of freedom associated with \code{tstat}
\item[\code{proportion}] assumed proportion of genes which are differentially expressed
\item[\code{v0.lim}] numeric vector of length 2, assumed lower and upper limits for the estimated unscaled standard deviation
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The values in each column of \code{tstat} are assumed to follow a mixture of an ordinary t-distribution, with mixing proportion \code{1-proportion}, and \code{(v0+v1)/v1} times a t-distribution, with mixing proportion \code{proportion}.
Here \code{v1=stdev.unscaled\textasciicircum{}2} and \code{v0} is the value to be estimated.
\end{Details}
\begin{Value}
Numeric vector of length equal to the number of columns of \code{tstat} and \code{stdev.unscaled}.
\end{Value}
\begin{Author}\relax
Gordon Smyth
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{ebayes}{ebayes}}
\end{SeeAlso}

