[Rd] Changes in the MEMSS package (data sets from Pinheiro and Bates, 2000, without the groupedData classes)

[Douglas Bates]

Some time ago Deepayan and I created a package called MEMSS for the
data sets from the nlme package  as data frames but not groupedData
objects.  Because of advances that Deepayan has made in lattice
graphics many of the specialized plotting methods for the groupedData
objects are no longer needed.  It is easier and less confusing to
store these data sets as data frames rather than as groupedData
objects.

I propose making two further changes in these objects.  Those objects
typically had factors converted to ordered factors in an artificial
way and I plan to revert them to factors.  Also, I will relabel any
factors with (26 or fewer) numeric levels with letters and to remove
the "ginfo" attribute.

Please tell me if this will cause you hardship because you have used
these data sets in your work and depend on the current formulation.