representation            package:methods            R Documentation

Describe A Class Representation

Description:

     Constructs a description of a class (without verifying the
     validity of the description).  A convenience function in calls to
     `setClass'.

Usage:

     representation(...)

Arguments:

     ...: The call to representation takes arguments that are single
          character strings.  Unnamed arguments are classes that a
          newly defined class extends; named arguments name the
          explicit slots in the new class, and specify what class each
          slot should have.     

Details:

     The `representation' function applies tests for the validity of
     the arguments.  Each must specify the name of a class.

     The classes named don't have to exist when `representation' is
     called, but if they do, then the function will check for any
     duplicate slot names introduced by each of the inherited classes.

Value:

     The value is just the list of arguments, after these have been
     checked for validity.

Author(s):

     John Chambers

References:

     The web page <URL: http://www.omegahat.org/RSMethods/index.html>
     is the primary documentation.

     The functions in this package emulate the facility for classes and
     methods described in Programming with Data, (John M. Chambers,
     Springer, 1998). See this book for further details and examples.

See Also:

     `setClass'

Examples:

     ## representation for a new class with a directly define slot "smooth"
     ## which should be a "numeric" object, and extending class "track"
     representation("track", smooth ="numeric")

