\HeaderA{formula.nls}{Extract Model Formula from nls Object}{formula.nls}
\keyword{models}{formula.nls}
\begin{Description}\relax
Returns the model used to fit \code{object}.
\end{Description}
\begin{Usage}
\begin{verbatim}
## S3 method for class 'nls':
formula(x, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] an object inheriting from class \code{"nls"}, representing
a nonlinear least squares fit.
\item[\code{...}] further arguments passed to or from other methods.
\end{ldescription}
\end{Arguments}
\begin{Value}
a formula representing the model used to obtain \code{object}.
\end{Value}
\begin{Author}\relax
Jose Pinheiro and Douglas Bates
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{nls}{nls}}, \code{\LinkA{formula}{formula}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
fm1 <- nls(circumference ~ A/(1+exp((B-age)/C)), Orange,
           start = list(A=160, B=700, C = 350))
formula(fm1)
\end{ExampleCode}
\end{Examples}

