summary                 package:base                 R Documentation

Object Summaries

Description:

     'summary' is a generic function used to produce result summaries
     of the results of various model fitting functions.  The function
     invokes particular 'methods' which depend on the 'class' of the
     first argument.

Usage:

     summary(object, ...)

     ## Default S3 method:
     summary(object, ..., digits = max(3, getOption("digits")-3))
     ## S3 method for class 'data.frame':
     summary(object, maxsum = 7,
            digits = max(3, getOption("digits")-3), ...)

     ## S3 method for class 'factor':
     summary(object, maxsum = 100, ...)

     ## S3 method for class 'matrix':
     summary(object, ...)

Arguments:

  object: an object for which a summary is desired.

  maxsum: integer, indicating how many levels should be shown for
          'factor's.

  digits: integer, used for number formatting with 'signif()' (for
          'summary.default') or 'format()' (for 'summary.data.frame').

     ...: additional arguments affecting the summary produced.

Details:

     For 'factor's, the frequency of the first 'maxsum - 1' most
     frequent levels is shown, where the less frequent levels are
     summarized in '"(Others)"' (resulting in 'maxsum' frequencies).

     The functions 'summary.lm' and 'summary.glm' are examples of
     particular methods which summarize the results produced by 'lm'
     and 'glm'.

Value:

     The form of the value returned by 'summary' depends on the class
     of its argument.  See the documentation of the particular methods
     for details of what is produced by that method.

References:

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

See Also:

     'anova', 'summary.glm', 'summary.lm'.

Examples:

     summary(attenu, digits = 4) #-> summary.data.frame(...), default precision
     summary(attenu $ station, maxsum = 20) #-> summary.factor(...)

     lst <- unclass(attenu$station) > 20 # logical with NAs
     ## summary.default() for logicals -- different from *.factor:
     summary(lst)
     summary(as.factor(lst))

