

lmeObject(nlme)                              R Documentation

_F_i_t_t_e_d _l_m_e _O_b_j_e_c_t

_D_e_s_c_r_i_p_t_i_o_n_:

     An object returned by the `lme' function, inheriting
     from class `lme' and representing a fitted linear
     mixed-effects model. Objects of this class have methods
     for the generic functions `anova', `coef', `fitted',
     `fixed.effects', `formula', `getGroups', `getResponse',
     `intervals', `logLik', `pairs', `plot', `predict',
     `print', `random.effects', `residuals', `summary', and
     `update'.

_V_a_l_u_e_:

     The following components must be included in a legiti-
     mate `lme' object.

   apVar: an approximate covariance matrix for the variance-
          covariance coefficients. If `apVar = FALSE' in the
          list of control values used in the call to `lme',
          this component is equal to `NULL'.

    call: a list containing an image of the `lme' call that
          produced the object.

coefficients: a list with two components, `fixed' and `ran-
          dom', where the first is a vector containing the
          estimated fixed effects and the second is a list
          of matrices with the estimated random effects for
          each level of grouping. For each matrix in the
          `random' list, the columns refer to the random
          effects and the rows to the groups.

contrasts: a list with the contrasts used to represent fac-
          tors in the fixed effects formula  and/or random
          effects formula. This information is important for
          making predictions from a new data frame in which
          not all levels of the original factors are
          observed. If no factors are used in the lme model,
          this component will be an empty list.

    dims: a list with basic dimensions used in the lme fit,
          including the components `N' - the number of
          observations in the data, `Q' - the number of
          grouping levels, `qvec' - the number of random
          effects at each level from innermost to outermost
          (last two values are equal to zero and correspond
          to the fixed effects and the response), `ngrps' -
          the number of groups at each level from innermost
          to outermost (last two values are one and corre-
          spond to the fixed effects and the response), and
          `ncol' - the number of columns in the model matrix
          for each level of grouping from innermost to out-
          ermost (last two values are equal to the number of
          fixed effects and one).

  fitted: a data frame with the fitted values as columns.
          The leftmost column corresponds to the population
          fixed effects (corresponding to the fixed effects
          only) and successive columns from left to right
          correspond to increasing levels of grouping.

   fixDF: a list with components `X' and `terms' specifying
          the denominator degrees of freedom for, respec-
          tively, t-tests for the individual fixed effects
          and F-tests for the fixed-effects terms in the
          models.

  groups: a data frame with the grouping factors as columns.
          The grouping level increases from left to right.

  logLik: the (restricted) log-likelihood at convergence.

  method: the estimation method: either `"ML"' for maximum
          likelihood, or `"REML"' for restricted maximum
          likelihood.

modelStruct: an object inheriting from class `lmeStruct',
          representing a list of mixed-effects model compo-
          nents, such as `reStruct', `corStruct', and `var-
          Func' objects.

 numIter: the number of iterations used in the iterative
          algorithm.

residuals: a data frame with the residuals as columns. The
          leftmost column corresponds to the population
          residuals and successive columns from left to
          right correspond to increasing levels of grouping.

   sigma: the estimated within-group error standard devia-
          tion.

  varFix: an approximate covariance matrix of the fixed
          effects estimates.

_A_u_t_h_o_r_(_s_)_:

     Jose Pinheiro and Douglas Bates

_S_e_e _A_l_s_o_:

     `lme', `lmeStruct'

