

   CCrreeaattee oorr aadddd ttoo aa ttiimmee--ccoonnssttaanntt ccoovvaarriiaattee ((ttccccoovv)) oobbjjeecctt

        tcctomat(ccov, names=NULL, oldccov=NULL)

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

       ccov: A vector or matrix containing time-constant base-
             line covariates with one row per individual, a
             model formula using vectors of the same size, or
             an object of class, tccov.

      names: The names of the covariates (if the matrix does
             not have column names).

    oldccov: An object of class, tccov, to which ccov is to be
             added.

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

        `tcctomat' transforms a vector or matrix containing
        time-constant baseline covariates or a model formula
        into an object of class, tccov, or combines two such
        objects.

        Such objects can be printed. Methods are available for
        extracting the covariates, their names, and the for-
        mula.

        To obtain the indexing to expand time-constant covari-
        ates to the size of a repeated measurements response,
        use `covind'.

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

        Returns an object of class, tccov, containing one
        matrix for the covariates (z$ccov) with one row per
        individual and possibly the model formula (z$linear).

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

        J.K. Lindsey

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

        `read.list', `restovec', `rmna', `tvctomat'.

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

        x1 <- gl(4,1)
        tcctomat(~x1)
        x2 <- c(0,0,1,1)
        tcctomat(~x2)

