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% $Id: nlsList.selfStart.Rd,v 1.7 2002/01/28 03:44:17 bates Exp $
\name{nlsList.selfStart}
\title{nlsList Fit from a selfStart Function}
\usage{
\method{nlsList}{selfStart}(model, data, start, control, level, subset, na.action, pool)
}
\alias{nlsList.selfStart}
\arguments{
\item{model}{a \code{selfStart} model function, which calculates
initial estimates for the model parameters from \code{data}.}
\item{data}{a data frame in which to interpret the variables in
\code{model}. Because no grouping factor can be specified in
\code{model}, \code{data} must inherit from class
\code{groupedData}.
}
\item{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{control}{a list of control values passed as the \code{control}
argument to \code{nls}. Defaults to an empty list.
}
\item{level}{an optional integer specifying the level of grouping to
be used when multiple nested levels of grouping are present.}
\item{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{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{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.
}
}
\description{
The response variable and primary covariate in \code{formula(data)}
are used together with \code{model} to construct the nonlinear model
formula. This is used in the \code{nls} calls and, because a
selfStarting model function can calculate initial estimates for its
parameters from the data, no starting estimates need to be provided.
}
\value{
a list of \code{nls} objects with as many components as the number of
groups defined by the grouping factor. A \code{NULL} value is assigned
to the components corresponding to clusters for which the \code{nls}
algorithm failed to converge. 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.
}
\seealso{
\code{\link{selfStart}}, \code{\link{groupedData}},
\code{\link{nls}}, \code{\link{nlsList}},
\code{\link{nlme.nlsList}}, \code{\link{nlsList.formula}}
}
\examples{
fm1 <- nlsList(SSasympOff, CO2)
summary(fm1)
}
\keyword{models}
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