Fixed sub-model

Primary fixed terms

The fixed list in the model formula
  • describes the fixed covariates, factors and interactions including special functions to be included in the ANOVA table,
  • generally begins with the reserved word mu which fits a constant term, mean or intercept,
  • are listed BEFORE any random terms,
  • the combined size of primary fixed terms is controlled by the !DENSE qualifier.
  • terms should be listed in a systematic Analysis of Variance order if tests of fixed effects are required because of the way ASReml generates singularities.

    Sparse fixed terms

    The !f sparse_fixed terms in model formula
  • are the fixed covariates (for example, the fixed lin(row) covariate now included in the model formula below), factors and interactions including special functions and reserved words (for example mv), for which ANOVA type tests are NOT required,
  • are listed AFTER any random terms,
  • include large (> 100 levels) terms.

    Example


     NIN Alliance Trial 1989
      variety
      ...
      row 22
      column 11
     nin89.asd !skip 1
     yield ~ mu variety !r repl !f mv lin(row)
     residual ar1(column).ar1(row)
    

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