StructureClasses           package:methods           R Documentation

Classes Corresponding to Basic Structures

Description:

     The virtual class 'structure' and classes that extend it are
     formal classes analogous to S language structures such as arrays
     and time-series.

Usage:

     ## The following class names can appear in method signatures,
     ## as the class in as() and is() expressions, and, except for
     ## the classes commented as VIRTUAL, in calls to new()

     "matrix"
     "array"
     "ts"

     "structure" ## VIRTUAL

Objects from the Classes:

     Objects can be created by calls of the form 'new(Class, ...)',
     where 'Class' is the quoted name of the specific class (e.g.,
     '"matrix"'), and the other arguments, if any, are interpreted as
     arguments to the corresponding function, e.g., to function
     'matrix()'.  There is no particular advantage over calling those
     functions directly, unless you are writing software designed to
     work for multiple classes, perhaps with the class name and the
     arguments passed in.

Extends:

     The specific classes all extend class '"structure"', directly, and
     class '"vector"', by class '"structure"'.

Methods:

     coerce Methods are defined to coerce arbitrary objects to these
          classes, by calling the corresponding basic function, for
          example, 'as(x, "matrix")' calls 'as.matrix(x)'.

     Ops, Math Group methods (see, e.g., 'S4groupGeneric') are defined
          for combinations of structures and vectors (including special
          cases for array and matrix), implementing the concept of
          vector structures as in the reference.

References:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

Examples:

     showClass("structure")

     ## explore a bit :
     showClass("ts")
     (ts0 <- new("ts"))
     str(ts0)

     showMethods("Ops") # six methods from these classes, but maybe many more

