R: Fix a Model Parameter and Conduct Likelihood Ratio Test

constrainFun {nadiv}

R Documentation

Fix a Model Parameter and Conduct Likelihood Ratio Test

Description

Given a model object from asreml and a range of estimates of the parameter, the function will supply the likelihood ratio test statistic for the comparison of the full model to one where the parameter of interest is constrained.

Usage

constrainFun(parameter.val, full, fm2, comp, G, mit = 600)

Arguments

`parameter.val`	a value for which the log-Likelihood of a model is to be calculated
`full`	the full model `asreml` object
`fm2`	starting values for the full model
`comp`	which variance component to constrain
`G`	logical, indicating if the component is part of the G structure
`mit`	numeric, indicating maximum number of iterations for the constrained asreml model

Value

A vector of length 1 returning either a numeric value corresponding to the likelihood ratio test statistic or else the missing value indicator NA.

Author(s)