\HeaderA{getInitial}{Get Initial Parameter Estimates}{getInitial}
\methaliasA{getInitial.default}{getInitial}{getInitial.default}
\methaliasA{getInitial.formula}{getInitial}{getInitial.formula}
\methaliasA{getInitial.selfStart}{getInitial}{getInitial.selfStart}
\keyword{models}{getInitial}
\keyword{nonlinear}{getInitial}
\keyword{manip}{getInitial}
\begin{Description}\relax
This function evaluates initial parameter estimates for a nonlinear
regression model.  If \code{data} is a parameterized data frame or
\code{pframe} object, its \code{parameters} attribute is returned.
Otherwise the object is examined to see if it contains a call to a
\code{selfStart} object whose \code{initial} attribute can be
evaluated.
\end{Description}
\begin{Usage}
\begin{verbatim}
getInitial(object, data, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] a formula or a \code{selfStart} model that defines a
nonlinear regression model
\item[\code{data}] a data frame in which the expressions in the formula or
arguments to the \code{selfStart} model can be evaluated
\item[\code{...}] optional additional arguments
\end{ldescription}
\end{Arguments}
\begin{Value}
A named numeric vector or list of starting estimates for the
parameters.  The construction of many \code{selfStart} models is such
that these "starting" estimates are, in fact, the converged parameter
estimates.
\end{Value}
\begin{Author}\relax
Jose Pinheiro and Douglas Bates
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{nls}{nls}}, 
\code{\LinkA{selfStart}{selfStart}},
\code{\LinkA{selfStart.default}{selfStart.default}}, \code{\LinkA{selfStart.formula}{selfStart.formula}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
PurTrt <- Puromycin[ Puromycin$state == "treated", ]
getInitial( rate ~ SSmicmen( conc, Vm, K ), PurTrt )
\end{ExampleCode}
\end{Examples}

