reml.lrt.asreml {asreml3Plus} | R Documentation |
Extracts the REML log likelhood and number of variance
parameters from two asreml
objects. It assumes that the second
asreml
object is the result of fitting a model that is a
reduced version of the model for the first object. In the case
where the reduced model is obtained by setting positively-constrained
variance parameters in the full model to zero, the positive.zero
argument should be set to TRUE
so that
the p-value is computed using a mixture of chi-square distributions as
described in Self and Liang (1987).
The function shecks that the models do not differ in either their fixed or sparse models.
The function reml.lrt
is provided for backwards compatibility.
reml.lrt.asreml(full.asreml.obj, reduced.asreml.obj, positive.zero = FALSE, bound.test.parameters = "none")
full.asreml.obj |
|
reduced.asreml.obj |
|
positive.zero |
Indicates whether the hypothesized values for the
variance components being tested are on the boundary
of the parameter space. For example, this is true
for positively-constrained variance components that,
under the reduced model, are zero. This argument does
not need to be set if |
bound.test.parameters |
Indicates whether for the variance components
being tested, at least some of the hypothesized values
are on the boundary of the parameter space. The default
is |
A data frame containing the log of the likelihood ratio, its degrees of freedom and its p-value.
The degrees of freedom for the test are computed as the difference
between the two models in the number of variance parameters that are
unfixed, nonsingular and unconstrained by relationships among them.
This procedure is only approriate when the null hypothesis is that all parameters are on the boundary of the parameter space or that all parameters are in the interior of the parameter space. Mixed cases have been discussed by Self and Liang (1987), but are not implemented here.
Self, S.G., and Liang, K-Y. (1987) Asymptotic Properties of Maximum Likelihood Estimators and Likelihood Ratio Tests Under Nonstandard Conditions. Journal of the American Statistical Association, 82, 605-10.
info.crit.asreml
, testranfix.asrtests
## Not run: reml.lrt.asreml(ICV.max, ICV.red, bound.test.parameters = "onlybound") ## End(Not run)