Dim.RdThis function is generic; method functions can be written to handle
specific classes of objects. Classes which already have methods for
this function include: "corSpatial", "corStruct",
"pdCompSymm", "pdDiag", "pdIdent", "pdMat",
and "pdSymm".
Dim(object, ...)will depend on the method function used; see the appropriate documentation.
If dim allowed more than one argument, there would be no
need for this generic function.