1% File src/library/stats/man/getInitial.Rd 2% Part of the R package, https://www.R-project.org 3% Copyright 1995-2010 R Core Team 4% Distributed under GPL 2 or later 5 6\name{getInitial} 7\encoding{UTF-8} 8\title{Get Initial Parameter Estimates} 9\alias{getInitial} 10\alias{getInitial.default} 11\alias{getInitial.formula} 12\alias{getInitial.selfStart} 13\usage{ 14getInitial(object, data, \dots) 15} 16\arguments{ 17 \item{object}{a formula or a \code{\link{selfStart}} model that defines a 18 nonlinear regression model} 19 \item{data}{a data frame in which the expressions in the formula or 20 arguments to the \code{selfStart} model can be evaluated} 21 \item{\dots}{optional additional arguments} 22} 23\description{ 24 This function evaluates initial parameter estimates for a nonlinear 25 regression model. If \code{data} is a parameterized data frame or 26 \code{pframe} object, its \code{parameters} attribute is returned. 27 Otherwise the object is examined to see if it contains a call to a 28 \code{selfStart} object whose \code{initial} attribute can be 29 evaluated. 30} 31\value{ 32 A named numeric vector or list of starting estimates for the 33 parameters. The construction of many \code{selfStart} models is such 34 that these "starting" estimates are, in fact, the converged parameter 35 estimates. 36} 37\author{\enc{José}{Jose} Pinheiro and Douglas Bates} 38\seealso{\code{\link{nls}}, \code{\link{selfStart}}, 39 \code{\link{selfStart.default}}, \code{\link{selfStart.formula}}. 40 Further, \code{\link[nlme]{nlsList}} from \CRANpkg{nlme}. 41} 42\examples{ 43PurTrt <- Puromycin[ Puromycin$state == "treated", ] 44print(getInitial( rate ~ SSmicmen( conc, Vm, K ), PurTrt ), digits = 3) 45} 46\keyword{models} 47\keyword{nonlinear} 48\keyword{manip} 49