

   CCoorrrreellaattiioonn SSttrruuccttuurree CCllaasssseess

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

        Standard classes of correlation structures
        (`corStruct') available in the `lme' library.

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

        Available standard classes:

     corAR1: autoregressive process of order 1.

    corARMA: autoregressive moving average process, with arbi-
             trary orders for the autoregressive and moving
             average components.

    corCAR1: continuous autoregressive process (AR(1) process
             for a continuous time covariate).

   corCompSymm: compound symmetry structure corresponding to a
             constant correlation.

     corExp: exponential spatial correlation.

    corGaus: Gaussian spatial correlation.

      corHF: Huyn-Feldt correlation.

     corLin: linear spatial correlation.

   corSpher: spherical spatial correlation.

    corSymm: general correlation matrix, with no additional
             structure.

   NNoottee::

        Users may define their own `corStruct' classes by spec-
        ifying a `constructor' function and, at a minimum,
        methods for the functions `corMatrix' and `coef'. For
        examples of these functions, see the methods for
        classes `corSymm' and `corAR1'.

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

        Jose Pinheiro and Douglas Bates

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

        `corAR1', `corARMA', `corCAR1', `corCompSymm', `cor-
        Exp', `corGaus', `corHF', `corLin', `corSpher',
        `corSymm'

