R/profileCI.R

In fields: Tools for Spatial Data

#
# fields  is a package for analysis of spatial data written for
# the R software environment.
# Copyright (C) 2022 Colorado School of Mines
# 1500 Illinois St., Golden, CO 80401
# Contact: Douglas Nychka,  douglasnychka@gmail.edu,
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with the R software environment if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
# or see http://www.r-project.org/Licenses/GPL-2
##END HEADER
profileCI<- function( obj, parName, 
                      CIlevel=.95, 
                      REML=FALSE){
  y<- obj$summary[,ifelse(REML,"lnProfileREML.FULL",
                           "lnProfileLike.FULL")]
  x<- obj$summary[,parName]
  logX<- log10( x)
  lGrid<- (seq( min(logX), max(logX),length.out=400))
  yGrid<- splint( logX, y, lGrid)
  yMax<- max(yGrid)
  ChiLevel<- qchisq(.95,1)
  ind<-  yMax - yGrid <= ChiLevel 
  CI<- range( lGrid[ind] )
  CI <- 10**CI
  return( CI)
}