R/clmm.start.R

In ordinal: Regression Models for Ordinal Data

#############################################################################
##    Copyright (c) 2010-2022 Rune Haubo Bojesen Christensen
##
##    This file is part of the ordinal package for R (*ordinal*)
##
##    *ordinal* 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.
##
##    *ordinal* 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.
##
##    A copy of the GNU General Public License is available at
##    <https://www.r-project.org/Licenses/> and/or
##    <http://www.gnu.org/licenses/>.
#############################################################################
## This file contains:
## Functions to compute starting values for clmm()s.

clmm.start <- function(frames, link, threshold) {
  ## get starting values from clm:
  fit <- with(frames,
              clm.fit(y=y, X=X, weights=wts, offset=off, link=link,
                      threshold=threshold))

  ## initialize variance parameters to zero:
  start <- c(fit$par, rep(0, length(frames$grList)))
  return(start)
}