anova                 package:stats                 R Documentation

Anova Tables

Description:

     Compute analysis of variance (or deviance) tables for one or more
     fitted model objects.

Usage:

     anova(object, ...)

Arguments:

  object: an object containing the results returned by a model fitting
          function (e.g., 'lm' or 'glm').

     ...: additional objects of the same type.

Value:

     This (generic) function returns an object of class 'anova'. These
     objects represent analysis-of-variance and analysis-of-deviance
     tables. When given a single argument it produces a table which
     tests whether the model terms are significant.

     When given a sequence of objects, 'anova' tests the models against
     one another in the order specified.

     The print method for 'anova' objects prints tables in a 'pretty'
     form.

Warning:

     The comparison between two or more models will only be valid if
     they are fitted to the same dataset. This may be a problem if
     there are missing values and R's default of 'na.action = na.omit'
     is used.

References:

     Chambers, J. M. and Hastie, T. J. (1992) _Statistical Models in
     S_, Wadsworth & Brooks/Cole.

See Also:

     'coefficients', 'effects', 'fitted.values', 'residuals',
     'summary', 'drop1', 'add1'.

