1% File src/library/stats/man/profile.nls.Rd 2% Part of the R package, https://www.R-project.org 3% Copyright 1995-2019 R Core Team 4% Distributed under GPL 2 or later 5 6\name{profile.nls} 7\alias{profile.nls} 8\title{Method for Profiling nls Objects} 9\description{ 10 Investigates the profile log-likelihood function for a fitted model of 11 class \code{"nls"}. 12} 13\usage{ 14\method{profile}{nls}(fitted, which = 1:npar, maxpts = 100, alphamax = 0.01, 15 delta.t = cutoff/5, \dots) 16} 17\arguments{ 18 \item{fitted}{the original fitted model object.} 19 \item{which}{the original model parameters which should be profiled. 20 This can be a numeric or character vector. 21 By default, all non-linear parameters are profiled.} 22 \item{maxpts}{maximum number of points to be used for profiling each 23 parameter.} 24 \item{alphamax}{highest significance level allowed 25 for the profile t-statistics.} 26 \item{delta.t}{suggested change on the scale of the profile 27 t-statistics. Default value chosen to allow profiling at about 28 10 parameter values.} 29 \item{\dots}{further arguments passed to or from other methods.} 30} 31\value{ 32 A list with an element for each parameter being profiled. The elements 33 are data-frames with two variables 34 \item{par.vals}{a matrix of parameter values for each fitted model.} 35 \item{tau}{the profile t-statistics.} 36} 37\details{ 38 The profile t-statistics is defined as the square root of change in 39 sum-of-squares divided by residual standard error with an 40 appropriate sign. 41} 42\references{ 43 Bates, D. M. and Watts, D. G. (1988), \emph{Nonlinear Regression Analysis 44 and Its Applications}, Wiley (chapter 6). 45} 46\author{ 47 Of the original version, 48 Douglas M. Bates and Saikat DebRoy 49} 50\seealso{ 51 \code{\link{nls}}, \code{\link{profile}}, \code{\link{plot.profile.nls}} 52} 53\examples{ 54\dontshow{od <- options(digits = 4)} 55# obtain the fitted object 56fm1 <- nls(demand ~ SSasympOrig(Time, A, lrc), data = BOD) 57# get the profile for the fitted model: default level is too extreme 58pr1 <- profile(fm1, alphamax = 0.05) 59# profiled values for the two parameters 60## IGNORE_RDIFF_BEGIN 61pr1$A 62pr1$lrc 63## IGNORE_RDIFF_END 64# see also example(plot.profile.nls) 65\dontshow{options(od)} 66} 67\keyword{nonlinear} 68\keyword{regression} 69\keyword{models} 70