[Rd] S3 vs S4 classes
Rossi, Peter E.
Peter.Rossi at chicagogsb.edu
Sat Feb 17 17:54:43 CET 2007
I have developed a package, bayesm, which uses existing classes of
objects. I would like
to add a new class corresponding to objects from this package.
I have been reading about classes and all sources tell me that I should
so-called "new" or S4 classes.
However, a major purpose of defining a class for my package would be to
add methods to the existing generic functions: print, plot, and
summary. My understanding
is that these functions work with the "old" or S3 classes.
If I want to use S4 classes, do I need to write new generic functions or
as way to "extend" the existing generics to work with S4 classes and
objects. I may
be using the wrong word here "extend" but I hope that everyone
understands the point.
If I have to write new generic functions, it is a simply matter of
registering the pre-existing
methods based on S3 objects? Or do you basicaly have to start from
scratch -- i.e.
the two types of classes, methods and generic functions are distinct?
Peter E. Rossi
Joseph T. and Bernice S. Lewis Professor of Marketing and Statistics
Editor, Quantitative Marketing and Economics
Rm 353, Graduate School of Business, U of Chicago
5807 S. Woodlawn Ave, Chicago IL 60637
Tel: (773) 702-7513 | Fax: (773) 834-2081
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