Optional argumentslevels6.2 The predict method 62a list of length the number of classified tables, and named by the classify set.Each list component is also a list, named by the margins of the classified table,of vectors specifying the levels at which predictions are required. If omitted,factors are predicted at each level, simple covariates are predicted at theiroverall mean and covariates used as a basis for splines or orthogonal polynomialsare predicted at their design points. The factors mv and units are alwaysignored.averagepresentparallelexceptignoreuseonlyusealiaseda list of length the number of classified tables, and named by the classify set,specifying which variables to include in the averaging set and optional vectorsof weights. Optionally, each component of the list is also a list, named by themargins of the classified table, of vectors specifying the weights to use in theaveraging process. If omitted, equal weights are used.a list of length the number of classified tables, and named by the classify set,specifying which variables to include in the present set for each table. Thepresent set is used when averaging is to be based only on cells with data. Eachcomponent of the list may be a character vector specifying the variables to beused in present averaging, or, may in turn also be a list. In this case, therecan be a maximum of two components, each a character vector of variablenames, representing non-overlapping present categorisations and one optionalcomponent named prwts containing a vector of weights to be used for averagingthe first present table only. The vector(s) of names may include variables inthe classify set but not those in the average set. At present, the model mustcontain the factor as a simple main effect.a list of length the number of classified tables, and named by the classify set,specifying which variables to expand in parallel. Each component of the list isa character vector specifying up to four of the classifying variables to expandin parallel.a list of length the number of classified tables, and named by the classify set,specifying which variables to exclude in the prediction process. That is, theprediction model includes all fitted model terms not in the exclude list. Eachcomponent of the list is a character vector specifying the variables to be excluded.a list of length the number of classified tables, and named by the classify set,specifying which variables to ignore in the prediction process. Each componentof the list is a character vector specifying the variables to be ignored.a list of length the number of classified tables, and named by the classify set,specifying which variables to add to the prediction model after the default ruleshave been invoked. Each component of the list is a character vector specifyingthe variables to be used.a list of length the number of classified tables, and named by the classify set,specifying which variables form the prediction model, that is, the default rulesare not invoked. Each component of the list is a character vector specifying thevariables to be used.a list of length the number of classified tables, and named by the classify set.Each component is a logical scalar (default F) that determines whether or notthe predicted value is returned for non-estimable functions.
6.2 The predict method 63sedvcova list of length the number of classified tables, and named by the classify set.Each component is a logical scalar (default F) that determines whether or notthe full standard error of difference matrix is returned.a list of length the number of classified tables, and named by the classify set.Each component is a logical scalar (default F) that determines whether or notthe full variance matrix of the predicted values is returned.6.2.1 An illustrationA simple example is the prediction of variety means from fitting model 2a (Section 4.2)to the NIN field trial data. Recall that a randomised block model with random replicateeffects is fitted to this data by:> rcb.asr rcb.pv rcb.pv$predictions$Variety$Variety$pvalsNotes:- Rep terms are ignored unless specifically included- mv is averaged over fixed levels- Variety is included in the prediction- (Intercept) is included in the prediction- mv is ignored in this predictionVariety predicted.value standard.error est.status1 ARAPAHOE 29.4375 3.855687 Estimable2 BRULE 26.0750 3.855687 Estimable3 BUCKSKIN 25.5625 3.855687 Estimable...54 TAM107 28.4000 3.855687 Estimable55 TAM200 21.2375 3.855687 Estimable56 VONA 23.6000 3.855687 Estimable$Variety$avsed[1] 4.979075The list orientated nature of predict.asreml() is potentially complex, particularly whenmore than one classified table is specified in a single function call. The principal reason forthis potential complexity lies in the fact that each predict.asreml() call requires at least onefurther iteration of the fitting routines (to construct the prediction design matrix). Forsituations where execution time is not limiting, it may be simpler to call predict.asreml()separately for each required classification table.To illustrate the potentially complex syntax of a predict function call, consider a hypotheticalexample where two predict tables are required, classified by factors (or compoundterms) ’A’ and ’B’. For the predictions classified by ’A’, present averaging is necessaryand the table of standard errors of difference is required. For those classified by ’B’, twomutually exclusive lists defining present averaging are required and we wish to weightthe cells of the first present hyper-table. The table of SED’s is not desired in this case.