\Header{nlsList}{List of nls Objects with a Common Model}
\methalias{nlsList.formula}{nlsList}
\alias{update.nlsList}{nlsList}
\keyword{models}{nlsList}
\begin{Description}\relax
\code{Data} is partitioned according to the levels of the grouping
factor defined in \code{model} and individual \code{nls} fits are
obtained for each \code{data} partition, using the model defined in
\code{model}.
\end{Description}
\begin{Usage}
\begin{verbatim}
nlsList(model, data, start, control, level, subset, na.action, pool)
## S3 method for class 'nlsList':
update(object, model, data, start, control, level,
      subset, na.action, pool, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] an object inheriting from class \code{nlsList}, representing
a list of fitted \code{nls} objects.
\item[\code{model}] either a nonlinear model formula, with the response on
the left of a \code{\textasciitilde{}} operator and an expression involving
parameters, covariates, and a grouping factor separated by the
\code{|} operator on the right, or a \code{selfStart} function.  The
method function \code{nlsList.selfStart} is documented separately.

\item[\code{data}] a data frame in which to interpret the variables named in
\code{model}.

\item[\code{start}] an optional named list with initial values for the
parameters to be estimated in \code{model}. It is passed as the
\code{start} argument to each \code{nls} call and is required when
the nonlinear function in \code{model} does not inherit from class
\code{selfStart}.

\item[\code{control}] a list of control values passed as the \code{control}
argument to \code{nls}. Defaults to an empty list.

\item[\code{level}] an optional integer specifying the level of grouping to
be used when multiple nested levels of grouping are present.
\item[\code{subset}] an optional expression indicating the subset of the rows of
\code{data} that should be used in the fit. This can be a logical
vector, or a numeric vector indicating which observation numbers are
to be included, or a  character  vector of the row names to be
included.  All observations are included by default.
\item[\code{na.action}] a function that indicates what should happen when the
data contain \code{NA}s.  The default action (\code{na.fail}) causes
\code{nlsList} to print an error message and terminate if there are any
incomplete observations.

\item[\code{pool}] an optional logical value that is preserved as an attribute of the
returned value.  This will be used as the default for \code{pool} in
calculations of standard deviations or standard errors for summaries.

\item[\code{...}] some methods for this generic require additional
arguments.  None are used in this method.
\end{ldescription}
\end{Arguments}
\begin{Value}
a list of \code{nls} objects with as many components as the number of
groups defined by the grouping factor. Generic functions such as
\code{coef}, \code{fixed.effects}, \code{lme}, \code{pairs},
\code{plot}, \code{predict}, \code{random.effects}, \code{summary},
and \code{update} have methods that can be applied to an \code{nlsList}
object.
\end{Value}
\begin{SeeAlso}\relax
\code{\Link{nls}}, \code{\Link{nlme.nlsList}}.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
data(CO2)
fm1 <- nlsList(uptake ~ SSasympOff(conc, Asym, lrc, c0),
   data = CO2, start = c(Asym = 30, lrc = -4.5, c0 = 52))
summary(fm1)
\end{ExampleCode}
\end{Examples}

