

   CCoommppaarree FFiitttteedd OObbjjeeccttss

        compareFits(object1, object2, which)

   AArrgguummeennttss::

   object1,object2: data frames, or matrices, with the same row
             names, but possibly different column names. These
             will usually correspond to coefficients from fit-
             ted objects with a grouping structure (e.g. `lme'
             and `lmList' objects).

      which: an optional integer of character vector indicating
             which columns in `object1' and `object2' are to be
             used in the returned object. Defaults to all
             columns.

   DDeessccrriippttiioonn::

        The columns in `object1' and `object2' are put together
        in matrices which allow direct comparison of the indi-
        vidual elements for each object. Missing columns in
        either object are replaced by `NA's.

   VVaalluuee::

        a three-dimensional array, with the third dimension
        given by the number of unique column names in either
        `object1' or `object2'. To each column name there cor-
        responds a matrix with as many rows as the rows in
        `object1' and two columns, corresponding to `object1'
        and `object2'. The returned object inherits from class
        `compareFits'.

   AAuutthhoorr((ss))::

        Jose Pinheiro and Douglas Bates

   SSeeee AAllssoo::

        `plot.compareFits', `pairs.compareFits', `comparePred',
        `coef', `random.effects'

   EExxaammpplleess::

        library(lme)
        data(Orthodont)
        fm1 <- lmList(Orthodont)
        fm2 <- lme(fm1)
        compareFits(coef(fm1), coef(fm2))

