| % File src/library/stats/man/getInitial.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2010 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{getInitial} |
| \encoding{UTF-8} |
| \title{Get Initial Parameter Estimates} |
| \alias{getInitial} |
| \alias{getInitial.default} |
| \alias{getInitial.formula} |
| \alias{getInitial.selfStart} |
| \usage{ |
| getInitial(object, data, \dots) |
| } |
| \arguments{ |
| \item{object}{a formula or a \code{\link{selfStart}} model that defines a |
| nonlinear regression model} |
| \item{data}{a data frame in which the expressions in the formula or |
| arguments to the \code{selfStart} model can be evaluated} |
| \item{\dots}{optional additional arguments} |
| } |
| \description{ |
| 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. |
| } |
| \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. |
| } |
| \author{\enc{José}{Jose} Pinheiro and Douglas Bates} |
| \seealso{\code{\link{nls}}, \code{\link{selfStart}}, |
| \code{\link{selfStart.default}}, \code{\link{selfStart.formula}}. |
| Further, \code{\link[nlme]{nlsList}} from \CRANpkg{nlme}. |
| } |
| \examples{ |
| PurTrt <- Puromycin[ Puromycin$state == "treated", ] |
| print(getInitial( rate ~ SSmicmen( conc, Vm, K ), PurTrt ), digits = 3) |
| } |
| \keyword{models} |
| \keyword{nonlinear} |
| \keyword{manip} |