asremlPlus (version 2.0-2)

addrm.terms.asrtests: Adds or removes the specified set terms from either the fixed or random model and records the change in a data.frame.

Description

The specified terms are simply added or removed from either the fixed or random model. No hypothesis testing is performed and no check is made for boundary or singular terms. A row is added to the test.summary data.frame stating whether fixed or random terms have been added or removed. Convergence in fitting the model is checked and a note included in the action if there was not. All components of the asrtests object are updated, although wald.tab is only updated if it is present in the supplied asrtests object.

Usage

addrm.terms.asrtests(terms = NULL, asrtests.obj, add = FALSE, 
                     random = FALSE, label = NULL,
                     denDF = "default", trace = FALSE, 
                     update = TRUE, set.terms = NULL, ignore.suffices = TRUE, 
                     constraints = "P", initial.values = NA, ...)

Arguments

terms

a single character string in the form of a formula which, after expansion, specifies the sum of a set of terms to be added or dropped.

asrtests.obj

an asrtests object for a fitted model that is a list containing an asreml object, a wald.tab data.frame with 4 columns, and a

add

whether to add or remove terms from the model.

random

whether terms are to added or removed from the fixed or random model.

label

a character string to use as the label in test.summary and which indicates what is being tested. If label is NULL, either Fixed terms or Random terms is used,

denDF

Specifies the enthod to use in computing approximate denominator degrees of freedom when wald.asreml is called. Can be none to suppress the computations, numeric for numerical methods,

trace

if TRUE then partial iteration details are displayed when ASReml-R functions are invoked; if FALSE then no output is displayed.

update

if TRUEthen update.asreml is called in removing and adding terms to the model. In doing this the arguments R.param and G.param are set to those in the asreml

set.terms

a character vector specifying the terms that are to have constraints and/or initial values set prior to fitting.

ignore.suffices

a logical vector specifying whether the suffices of the asreml-assigned names of the variance terms (i.e. the information to the right of an "!", other than "R!") is to be igno

constraints

a character vector specifying the constraints to be applied to the terms specified in terms. This vector must be of length one or the same length as terms. If it i

initial.values

a character vector specifying the initial values for the terms specified in terms. This vector must be of length one or the same length as terms. If it is of leng

...

further arguments passed to asreml and to wald.asreml.

Value

• An asrtests object, which is a list containing:
  1. asreml.obj: anasremlobject containing the fit of the model after all boundary and singular terms have been removed;
  2. wald.tab: a 4-columndata.framecontaining a pseudo-anova table for the fixed terms produced bywald.asreml;
  3. test.summary: adata.framewith columnsterm,DF,denDF,pandaction. A row is added to it for each term that is dropped, added or tested or a note that several terms have been added or removed. A row contains the name of the term, the DF, the p-value and the action taken. Possible codes are:Dropped,Retained,Swapped,Unswapped,Significant,Nonsignificant,Absent,Added,RemovedandBoundary. If the changed model did not converge,Unconvergedwill be added to the code. Note that the logicalasreml.obj$convergealso reflects whether there is convergence.

See Also

asrtests, rmboundary.asrtests, testranfix.asrtests, testrcov.asrtests, newfit.asreml, sig.devn.reparam.asrtests, choose.model.asrtests

Examples

terms <- "(Date/(Sources * (Type + Species)))"
  current.asrt <- addrm.terms.asrtests(terms, current.asrt, add = TRUE)

  current.asrt <- addrm.terms.asrtests("A + B", current.asrt, denDF = "algebraic")