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

From: Douglas Bates <>
Date: Tue, 24 Jul 2007 10:31:15 -0500

On 7/24/07, Gabor Grothendieck <> wrote:
> Does this include datasets such as CO2 and ChickWeight
> which are in the datasets package?

> Could you post a list of the specific datasets you are referring to
> so there is no confusion what this is about.

I am only referring to the datasets in the MEMSS package. There will be CO2, ChickWeight, Theoph, etc. datasets in the MEMSS package without the groupedData classes. However, the versions in the datasets package will stay as they are unless and until R-core decides to change them.

Having datasets in the datasets package and in the MEMSS package with the same name will produce a warning when you attach the MEMSS package. However, I generally use datasets with a call like

data(Rail, package = "MEMSS")

which doesn't cause a warning (it is assumed that if you are this explicit about the data set then you probably want exactly that version and haven't accidently overridden the other).

The bottom line is that unless you have been in the habit of attaching the MEMSS package or getting data sets from it as above then you won't notice any difference.

> On 7/24/07, Douglas Bates <> wrote:
> > 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.
> >
> > ______________________________________________
> > mailing list
> >
> >
> mailing list Received on Tue 24 Jul 2007 - 16:09:53 GMT

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