old-classes: Class "unit" and "viewport" as S4 classes
Description
Package "hexbin" now uses S4 classes throughout and hence
needs to setOldClass
both "unit"
and
"viewport"
(which are S3 classes from the grid package),
in order to be able to use those in slots of its own classes.Objects from the Class
A virtual Class: No objects may be
created from it.Extends
Class "oldClass"
, directly.Methods
No methods defined with class "unit" in the signature.