

   EExxttrraacctt PPoooolleedd SSttaannddaarrdd DDeevviiaattiioonn

        pooledSD(object)

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

     object: an object inheriting from class `lmList'.

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

        The pooled estimated standard deviation is obtained by
        adding together the residual sum of squares for each
        non-null element of `object', dividing by the sum of
        the corresponding residual degrees-of-freedom, and tak-
        ing the square-root.

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

        the pooled standard deviation for the non-null elements
        of `object', with an attribute `df' with the number of
        degrees-of-freedom used in the estimation.

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

        Jose Pinheiro and Douglas Bates

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

        `lmList', `lm'

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

        library(lme)
        data(Orthodont)
        fm1 <- lmList(Orthodont)
        pooledSD(fm1)

